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Volgenau School of Engineering

2020

Senior Design ProjectsD E P A R T M E N T O F M E C H A N I C A L E N G I N E E R I N G

Welcome

MECHANICAL ENGINEERING DESIGN is a two-semester capstone design sequence. The capstone design courses provide students an industry-like experience that includes technical, business, and professional skills

development. Topics vary, but include engineering proposal development, design, simulation, analyses, fabrication, test, and related program management activities.

In the fall semester, students form design teams and then progress from the proposal phase through the critical design stages of the project. In the spring, they continue with prototyping, fabricating, testing, and evaluation. Students share their findings and document their designs during a Capstone Day event. The 2019 – 2020 academic year marks the fourth time the George Mason University Department of Mechanical Engineering has offered this sequence and the first time we’ve hosted Capstone Day as a virtual event. We are enormously proud of the accomplishments of the 14 student teams.

Benefits to StudentsIndustry wants graduating engineers to be well rounded, have a strong technical foundation, and possess strong business acumen. The capstone design sequence provides students a real-world experience to ensure they are ready to practice engineering when they graduate. The scope replicates the engineering project business cycle, and the students’ involvement provides a competitive edge, not only during the hiring process, but also as they begin their careers.

Benefits to SponsorsIndustry sponsors benefit by engaging in our students’ capstone experience through the advancement of a meaningful project, the work of five students for 30 weeks, and the low-risk evaluation of alternative solution concepts. Over the two semesters, sponsors may evaluate students as potential new employees and work with faculty subject-matter experts assigned to the project. Sponsorship also provides goodwill and brand awareness for their organization.

Milestones and DeliverablesAll student teams produce the following milestones and deliverables for their sponsors:

■ Proposal in response to sponsor statement of work; ■ System design review; ■ Preliminary design review; ■ Critical design review; ■ Comprehensive reports that document the design process, prototype fabrication, testing and evaluation, plus attendant analyses, simulation and modeling results;

■ Virtual Capstone Day presentation.

Please join me in congratulating the undergraduates, faculty, and sponsors

for their outstanding work.

Oscar Barton, Jr., PhD, PEChair, Department of Mechanical Engineering

THE FUTURE OF ENGINEERING IS HERE.

2020 Senior Design ProjectsGeorge Mason University and the Volgenau School of Engineering are proud of the

significant accomplishments of the student teams. While their work was interrupted by the COVID-19 outbreak, they rose to the challenge and their ingenuity shines

through in the projects presented at Capstone Day.

Team Barracuda . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Project: Promoting Electric Propulsion: Propulsion Team

Team BOAT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4Project: Promoting Electric Propulsion: Hull Team

Team GreenMARK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6Project: Waste Disposal Infrastructure Improvement

Team CAVS—Chemical Agent Vehicle Sprayer . . . . . . . . . . . . . . . . . . . . . 8Project: Localized Vehicle Contamination Detection

Team VCI—Vehicle Contamination Inspection . . . . . . . . . . . . . . . . . . . . 10Project: Vehicle’s Undercarriage Contamination Inspection

Team LRDZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Project: Accelerated Corrosion Test Chamber

Team DewPointe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Project: Accelerated Corrosion Test Chamber

Team DA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16Project: Autonomous Paint Application & Quality Detection System

Team PHIL—Portable Hazard Imager and Locator . . . . . . . . . . . . . . . . 18Project: Patriot Green Fund Infrastructure Improvement Project (Thunder Rat II)

Team AutoLine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20Project: Printed Circuitboard Accumulator

Team VIPER—Versatile Inline Pipe Examination Robot . . . . . . . . . . . .22Project: Versatile Inline Pipe Examination Robot (VIPER)

Team PairaMax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24Project: Backpack Chair

Team CHARIOT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26Project: Handcycle Modification Project

Team SEAD—Secure Efficient Accessible Delivery . . . . . . . . . . . . . . . .28Project: Design and Fabrication of a Home Delivery Receptacle

1mechanical.gmu.edu 2020 Department of Mechanical Engineering Senior Design

Team Barracuda

Promoting Electric Propulsion: Propulsion Team

THE AMERICAN SOCIETY OF NAVAL ENGINEERS (ASNE) tasked Team Barracuda to develop an electric marine propulsion system for use on the vessel developed by Team BOAT. The propulsion system fabricated must complete and race in the ASNE Promoting Electric

Propulsion (PEP) for Small Craft competition course, which has a length of five miles with five laps (one mile per lap) and nine turns.

An outboard configuration was in line with the sponsor’s criterion for the vessel team to create a template one-design vessel. This configuration allows for easy attachment to the vessel, which enables the propulsion system to not heavily influence the vessel template design. Two alternative outboard designs were explored: jet drive outboard and a conventional design outboard. Due to the simplicity of design, budget constraints, and equipment available for fabrication, the conventional outboard design was chosen.

The motor and battery selection drive the team’s conventional outboard design. Three options were explored for electric motors: permanent magnet alternating current (PMAC), brushless direct current (BLDC), and brushed permanent magnet DC (PMDC). PMAC motors operate at higher efficiencies, greater torque densities, and higher rotational speeds compared to a PMDC motor. Due to the availability of compatible controllers for the electric motor, a PMAC motor was chosen.

Two types of battery sources were explored: absorbent glass material (AGM), and lithium-ion (LiFePO4). Although lithium-ion batteries are lighter weight and offer a better depth of discharge, absorbent glass material batteries were chosen due to relative cost. Although AGM batteries are cost-effective at the same battery rating, the team recognized that the cost would still be a huge part of the budget.

To stay within budget, the team repurposed a casing and parts from gas outboard motors donated by the Washington Marina. Much of the team’s design focused on innovations toward converting the donated gas outboard to electric, including the design of a jaw coupling to transmit rotational motion from the electric motor to the driveshaft. A hollow cylindrical rod was designed to mate the driveshaft end and jaw coupling and to allow proper alignment and connection. A placement bracket was designed to hold the motor controller, electric components, and electric motor stationary

Team Barracuda TEAM MEMBERS: Joseph Canlas (team lead), Michael Geary, Mahmoud Hassan Mohamed, Dean Mueller, Steven Tran

SPONSOR: American Society of Naval Engineers (ASNE)

FACULTY ADVISOR: Dr. Leigh McCue

ACKNOWLEDGEMENTS: Mr. Mike Briscoe, Mr. Fred Latrash, and CAPT Dale Lumme, USN (Ret.), ASNE; Dr. Steve Russell, Office of Naval Research (ONR); Mr. Tom Kyle, Washington Marina; Dr. Leigh McCue and Mr. Johnnie Hall IV, GMU

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and Original Deliverables

2 THE FUTURE OF ENGINEERING IS HERE.

in the upper unit. Electrical components were placed in the upper unit to seal these components in the waterproof outboard hood.

Analysis provides the team with cost-effective estimated results on how the system could perform. Inventor finite element analysis (FEA) software was utilized for linear static analysis on three critical parts: the machine key, the hollow cylinder rod, and the motor placement bracket. The maximum torque (imparted by the motor) on the machine key and hollow cylindrical rod were simulated using the FEA software. For the bracket, the weight of components and vibrations imparted by the electric motor were simulated. The results showed that the dimensions and material choice for the critical parts were appropriate for fabrication, as well as where stress concentrations may occur. These stress concentrations allowed the team to evaluate where cyclical dynamic loads may cause failure.

Fatigue stress life analysis was done using Nastran FEA software. Mechanical fatigue on the placement bracket, caused by the vibration of the rotating motor and the weight load, showed that the bracket can endure numerous cycles where fatigue life is sufficient for long-time use.

Dynamic loads for the shaft hub piece analysis were

constrained to full torque load, half torque load, and unloaded, to represent the operation of the system in various throttles. With dynamic loads, the shaft hub piece was found to be able to also endure numerous cycles where fatigue life is sufficient for long-time use.

Heat transfer analysis was carried out on the motor controller where overheating could cause failure of the system. Conditions for the motor controller with and without a heatsink were mathematically modeled to determine the controller operating temperature during competition. The team determined that an aluminum finned heatsink and a fan could moderate the motor controller temperature. The heatsink increased the surface area for heat to diffuse from, while the fan increased the airflow rate. Working in unison, the heatsink and controller increase the overall convective cooling to keep the motor controller from overheating.

Looking to the future, the system was designed for maximum flexibility with the procurement of a new electric motor if desired. Whether there are different horsepower requirements or an increase in power from a different battery configuration, the motor controller can be reprogrammed to accommodate higher power inputs for the current electric motor chosen.


Team BOAT TEAM MEMBERS: Alexander Stickel (team lead), Brian Lichtenfels, Joshua Stickel, Philip Stolfi

SPONSOR: American Society of Naval Engineers (ASNE)

FACULTY ADVISOR: Dr. Leigh McCue

ACKNOWLEDGEMENTS: Mr. Mike Briscoe, Mr. Fred Latrash, and CAPT Dale Lumme, USN (Ret.), ASNE; Dr. Steve Russell, ONR; The Alexandria Seaport Foundation; Mr. John Recktenwald, Mr. Denys Kurathenko, and Mr. Johnnie Hall IV, GMU; Prof. Ben Ashwart, Prof. Peter Winant, Prof. Robert Handler, Dr. Erik Knudsen, Prof. Jeffrey Moran, Prof. Ahmad Shahba, and Dr. Colin Reagle, GMU

Team BOAT

Promoting Electric Propulsion: Hull Team

TEAM BOAT WAS TASKED with creating an efficient and easy to construct hull which could serve as a platform for different types of electric propulsion systems. Team BOAT worked closely with the electric propulsion Team Barracuda. The combined BOAT/Barracuda projects are planned for

entry in the American Society of Naval Engineers (ASNE) Promoting Electric Propulsion (PEP) for Small Craft race. The hull was designed for use in a one-design style competition.

Alternative Designs, Evaluation, and SelectionInitially, four designs were considered: two monohulls and two trimarans. Designs with both flat top and bottom or rounded top and bottom were considered in order to evaluate tradeoffs between ease of construction and hydrodynamic efficiency. The hull has been designed to carry at least 1,400 pounds, with outrigger supports that are standard steel pipes. All designs had a hull shape dictated by the Sears-Haack equation, a formula designed to minimize wave drag. A displacement hull was chosen over planing or other hulls in case future teams could not provide enough power to get their hull to plane, which would cause a drastic difference in performance between two similar engine designs.

Final Design DescriptionTeam BOAT moved forward with the rounded trimaran, with intent to utilize a 3D hang printer

for quick, cheap manufacture of complex hull mold geometries. This allowed Team BOAT to move forward without compromising performance.

FabricationThe team decided that to construct such a complicated hull shape, some form of mold would have to be made and used to shape the final hull. Utilizing an external machine shop to cut large foam blocks was considered, but deemed to be both cost and time prohibitive. Instead, the team supported upgrades to the 3D hang printer operated by the Mason Innovation Exchange (MIX) for 3D printing the hull mold in sections. The hang printer has maximum print dimensions in excess of 3 feet by 3 feet with a maximum theoretical height of the ceiling, but has a pyramid shaped print volume, meaning taller objects must narrow accordingly.

The mold was to be printed in smaller sections, which would be moved to the location where they

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would be fitted around a wooden frame then glued in place before being covered in fiberglass. Because of the relative thinness and potential strength benefits, the plastic mold would be left in. The wooden frame would be made by printing out a full-scale cutting template that would then be affixed to wood and cut out, then assembled using mortise and tenon joints for maximum strength.

Analysis and ResearchNaval engineering is a complex subject, so a great deal of research was needed to even begin to understand the more technical documents’ terminology. With extensive help from our advisor Dr. McCue, we were able to progress.

One of the largest sources of utilized knowledge was Design for Fast Sailing by Edmond Bruce and Harry Morss. Bruce and Morss compiled many of the key design factors and their impact, including length to breadth ratios and their effect on drag. The 8:1 ratio was chosen due to its balance of low drag and practical size.

Displacement craft are limited at their top speed by the wave generation drag. This led to the Sears-Haack body shape chosen, a shape that is mathematically perfect for mitigating wave drag, leading to our very sleek, streamlined looking hull.

Structural stability was also a concern given the potentially large load of batteries, resulting in finite element model studies being done to determine the maximum stresses on the craft. These ultimately led to the wooden frame, as it proved to be a cost-effective way to strengthen the craft to within acceptable levels.

ConclusionsThe hull was designed for minimal drag in a straight line, allowing the electric propulsion system to be the deciding factor in a race. All components can survive the expected loads with at least a safety factor of 1.5 and should provide a stable, fast platform mount capable of supporting outboard electric motors.

An example of a body made with the Sears-Haack equation

The final design for the hull


Team GreenMARKTEAM MEMBERS: Austin Lazo (team lead), Randy Castro, Maris Ravenstahl, Khalid Rayan

SPONSOR: George Mason University—Patriot Green Fund (GMU—PGF)

FACULTY ADVISOR: Prof. Roger Agbanlog

ACKNOWLEDGEMENTS: Mr. Johnnie Hall IV, Ms. Sarah D’alexander, Mr. Steven Pulis, and Dr. Erik Knudsen, GMU

Team GreenMARK

Waste Disposal Infrastructure Improvement

IN AN EFFORT TO PROGRESS THE WASTE REDUCTION SUSTAINABILITY INITIATIVE set out by the Patriot Green Fund, the George Mason University Facilities Management commissioned Team GreenMARK to provide a means of quantifying waste in Mason’s Vert-I-Pack ® compactors.

These waste compactors can be found throughout Mason’s campuses, with over 40 units currently in service. With the successful completion of this project, Mason Facilities would gain access to accurate waste data, enabling more cost-efficient waste management. For GreenMARK, this project provided an opportunity to give back in a way that would benefit the Mason community for years to come.

First StepsGreenMARK was tasked with the design and fabrication of a sensing system capable of measuring and reporting the weight, volume, and density of waste within a compactor. The design was more accurately defined as a proof-of-concept, as Mason Facilities expected that full completion of the project would require multiple years of work. As such, GreenMARK’s goal for the 2019-2020 academic year was to provide a model prototype (approximately 1:3 scale) capable of quantifying waste and to make high-level design decisions from the insight gained that would ensure the project’s eventual success.

Two direct measurements were needed: 1) Force normal to the inner surface of the compactor receptacle, used to calculate the weight of contents, and 2) The height/level of the contained waste, used to extrapolate volume given knowledge of the receptacle’s internal geometry. From these two values, density would then be calculated.

Preliminary research showed that utilizing an Ultrasonic Sensor (USS) would be the most effective means of measuring volume, moving the focus to weight measurement. GreenMARK considered several different approaches to accurately measure weight, and ultimately decided on a design that implemented load cell sensors.

The final design consisted of a USS securely mounted to the container, directed to obtain the most consistent and accurate distance measurement. The weight was measured via a set of four load cells arranged in an axisymmetric, rectangular pattern with a 3/16-inch steel plate resting on top. The load cells were housed within 3D-printed bases fixed to the container bottom, and weldments were added at the corners

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( just above the plate) to act as guide rails, so as to limit horizontal translation and ensure the plate would not fall out of the container upon tipping. Both of these systems were run through appropriate data processing equipment, and a Raspberry Pi was used to calculate density, as well as consolidate and display the data. All electronics were housed outside the receptacle.

Pieces of the PuzzleWith fabrication of the model container and compacting plate underway, the range and accuracy of the sensing components were verified concurrently utilizing rigorous testing procedures. For the load cells, this involved comparing empirically derived weight measurements to the manufacturer-provided calibration curve. For the USS, GreenMARK devised a testing apparatus and procedure to verify that the functionality, range, accuracy, and resolution were all in accordance with manufacturer specifications, and applicable to the project. The results of these tests provided confidence in the load cell implementation strategy while yielding much needed insight into the capabilities of the USS. Through testing, the USS was found to meet specification only when directed completely normal to the desired surface (± 5º).

As was expected, fabrication came with its own set of challenges. In the assembly of the model container, minor

modifications to the lower portion were necessary for ease of manufacturing, requiring the re-cutting of all lower side panels. Additionally, with the insight from the USS testing, a new method of mounting the sensor above the container’s center was devised. This revision enabled the USS to provide actionable data for use in the overall system and allowed room for optimization of that portion of the overall sensing system.

Findings and the FutureHaving found success in testing the weight measurement system with weight plates in a variety of distribution patterns, this strategy could be improved by modifying the plate surface geometry to better capture waste resting on the angled portions of the receptacle. As for the volume sensing, the extent to which the rough surfaces of compacted materials could cause inaccuracies was underestimated. While GreenMARK was able to achieve relatively accurate volume measurements under ideal conditions, the design was unable to sufficiently account for real-world inconsistencies. That said, many alternative methods exist and these results will act as guidance for future utilization of such methods. Ultimately, GreenMARK’s proof-of-concept proved successful as a first iteration of a sensing system that met the needs set out by Mason Facilities, providing a firm foundation for the design of its successor.


Team CAVSTEAM MEMBERS: Vineet Nair (team lead), Matias Gipler, Devin Rolon, Ivory Sarceño, Angelica Watson

SPONSOR: Defense Threat Reduction Agency (DTRA)

FACULTY ADVISOR: Dr. Pei Dong

ACKNOWLEDGEMENTS: Dr. Erik Knudsen and Dr. Nathan M. Kathir, GMU

Team CAVSChemical Agent Vehicle Sprayer

Localized Vehicle Contamination Detection

CHEMICAL WARFARE AGENTS (CWAs) are a type of weapon of mass destruction that can cause severe pain, lung damage, blindness, and death. In war-torn areas, it is very possible that military vehicles can become exposed to these harmful chemicals such as chlorine, sarin or

mustard gas. This is the reason why the military conducts thorough inspections of all vehicles returning to “clean” zones.

The current techniques used to inspect vehicles before entering clean zones are labor intensive, monotonous, and time-consuming to the personnel involved. Vehicles are manually sprayed with detection sprays (Agentase C2) and are visually inspected for contamination, determined by a red color change. This process has proven costly, since safely disposing the wastewater after this process is a concern.

In order to address the problems of current inspection methods, the Defense Threat Reduction Agency (DTRA) has asked Team CAVS to develop a prototype that can automate the spraying process and map contamination sites. When contaminants are successfully located, the decontamination process will only need to target specific areas, thus minimizing waste and saving time.

In order to meet DTRA’s requirements, Team CAVS developed three original design approaches. The first design alternative was a sprayer frame that could be manually placed on any side of the vehicle and accurately spray and map

contaminants by using the frame as a plane and coordinate system.

The second proposed solution was a semi-autonomous robot that would be able to navigate around the vehicle using sensors to spray and locate contaminants, and the third alternative was also a robot, but with the constraint that it can only spray the length of one side of a vehicle at a time from a preset distance.

Team CAVS analyzed the three potential solutions from the perspectives of cost, ease of manufacturability, spray ability, programmability, and portability using a weighted decision matrix.

The sprayer frame was designed to be portable; it is easily assembled and disassembled by removing a few bolts and angle brackets. The fluid delivery system was kept separate from the

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frame to reduce the weight of the frame. Using a Raspberry Pi and Arduino UNO, Team CAVS was able to program a spraying and image processing sequence. NEMA-23 stepper motors were used to control the vertical and lateral motion of the sprayer module, and a solenoid valve was programmed to control spraying. After the Agentase C2 reacts with the chemical surrogate, the deployable sprayer takes six pictures in a three by two grid and the images are immediately processed for contamination. Images containing red color change larger than two centimeters squared were saved in a folder with its location.

Team CAVS faced several unique challenges. The team noticed that the 90-degree brackets selected for the corners of the frame were too thin and would flex under heavy loads. In order to reinforce the strength of the frame, the team resorted to welding certain sections. A power supply unit housed our electric components consisting of drivers, relay boards, and switches. A pump was fed by plastic tubing connected to a reservoir for our fluid delivery system. Due to unforeseen circumstances, the frame was never fully assembled.

Team CAVS designed a program that could coordinate the movement of the sprayer and camera module and later take pictures to map the contamination sites. To test the image

analysis program, Team CAVS used a canvas and red paint. Choosing the right nozzle was an important factor for fluid

delivery. The nozzle needed to provide a bandwidth height of one meter to cover a desired height of two meters in two horizontal passes. Team CAVS tested several brass and plastic angle nozzles using a pressure of 30 psi and two gallons per minute flow rate. The 50-degree brass nozzle was selected using spray height as the criteria.

A finite element model in Nastran was created to assess the structural integrity of the frame. The decision to 3D print the brackets was weighed against precision milled aluminum brackets. After running the analysis, it was shown that 3D printed parts using ABS could support the tensioning system and stepper motors, saving cost and time.

Although the final design is not fully assembled, it is capable of mapping contamination with a 95 percent accuracy.

This design addresses the problems of having military personnel manually inspect a vehicle. Since the device is autonomous, it can be operated at a safe distance. It also aims to address the amount of waste produced by current decontamination techniques by targeting contamination sites.


Team VCITEAM MEMBERS: Zoe Waide (team lead), Jack Miller, Thanh Tran, Robert Yew

SPONSOR: Defense Threat Reduction Agency (DTRA)

FACULTY ADVISOR: Dr. Pei Dong

ACKNOWLEDGEMENTS: Mr. Nick Dobson and Mr. Stephen Waide, ThermaDynamicsRail LLC; Mr. Damien Miller, US AFOSI (Retired); Mr. Johnnie Hall IV, Mr. Sandor Nyerges, and Dr. Daniel Lofaro, GMU; Mr. Malcolm Forbes, GMU Alumni

Team VCIVehicle Contamination Inspection

Vehicle’s Undercarriage Contamination Inspection

TEAM VEHICLE CONTAMINATION INSPECTION (VCI) has taken on the challenge to design and fabricate a device that can locate, identify, and decontaminate contamination on vehicle undercarriages. This is specific to, but not limited to, vehicles that have been exposed

to a chemical warfare environment. The project was sponsored by the Defense Threat Reduction Agency (DTRA).

The operation of the device utilizes Agent Disclosure Spray (ADS) and the Contamination Indicator/Decontamination Assurance System (CIDAS). The process begins with applying ADS to the undercarriage of the vehicle in question. This initiates a chemical reaction, in which contaminated areas on the vehicle turns red to indicate the presence of a contaminant. The colored area then can be decontaminated by applying CIDAS to its surface.

Final Design DescriptionTo fully capture the final overall design of the device, the systems can be broken down to fluid, actuation, and vision systems.

The fluid system of the device includes a tank, a pump, a nozzle, and a solenoid control valve. The tank and pump will be placed on the side of the device. The nozzle and the solenoid control valve are mounted directly on a block within the device.

The structure of the device consists of two main systems: the long rail system, which moves along the vertical axis of the vehicle, and the cross rail system, which moves along the horizontal axis across the vehicle. Both of these systems are driven using a lead-screw drive system, which is controlled and operated through a combination of motors, drivers, and Arduino Uno.

A camera mounted on the block along with the spray nozzle allows the operators to observe and map the contaminated areas of the vehicle’s undercarriage. The camera is controlled by a Raspberry Pi. An algorithm for the vision system allows it to automatically recognize the contaminated area and determine its size using Python and the open-source OpenCV libraries for Python.

Discussion of and Challenges in FabricationChallenges which arose during fabrication included much delay caused by reevaluating, reordering, and retesting components repeatedly. Other design challenges included a constantly changing schematic

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of the device, and thus components which were intended for one version of the design were no longer usable in the next version. In addition, fabrication processes would take much longer than anticipated. Amongst all the difficulties, it was valuable to face the reality of the pace of fabrication and the roadblocks that accompany the building process.

Analysis, Simulation, Modeling, and Testing Results ■ Motor Testing—Both stepper motors used in the long and cross rail systems were tested to determine optimal rotational acceleration, velocity, and torque. These parameters were applied in finite element analysis simulations to determine resulting stresses in the system. The final design was optimized for mechanical strength, weight, and operational efficiency.

■ Nozzle testing—An initial test was run using the female nozzle with a 120-degree spray radius. Using the purchased pump and hoses, the nozzle was able to output a sufficient spray for the fluid coverage requirements. The spray coming from the nozzle at the pump’s power of 120 VAC was less uniform than expected, but still adequate.

■ Code testing—Using a test image of multicolored dots

against a white background, the code to control the vision system was able to identify the red dots in the image and calculate the total area of red coloring in the image. The color red was chosen because the contamination on the vehicle undercarriage turns a red color when exposed to agent disclosure spray.

Conclusions, Benefits, and ApplicationsReducing risk of dangers to human life is an utmost priority in a wartime environment, and such a goal was behind the device designed and fabricated by Team VCI. With the device, the user no longer has to approach the vehicle at close proximity to decontaminate it and risk exposure to harmful substances.

The benefits of using the device also include increased accuracy of contamination identification, such as size contaminated region and location. The proposed design can lead to relatively fast inspection times, with the current process taking around 30 minutes to complete, and using the system designed by VCI, it would take under three minutes. Applications include military vehicles returning from exposure to wartime chemicals that require evaluation before being eligible for use again.


Team LRDZTEAM MEMBERS: John Recktenwald (team lead), Farhad Dawodi, Jack Lloyd, Wint Zaw

SPONSOR: Office of Naval Research (ONR)

FACULTY ADVISOR: Dr. Mehdi Amiri

ACKNOWLEDGEMENTS: Dr. Anisur Rahman, ONR; Mr. Johnnie Hall IV, GMU

Team LRDZ

Accelerated Corrosion Test Chamber

CORROSION OF METAL COMPONENTS in infrastructure, automobiles, and aircraft is estimated to cost the global economy $2.5 trillion annually.1 It is estimated that by properly applying corrosion testing and protection this preventable deterioration could be reduced by up to

35 percent or $875 billion.1 Team LRDZ has been commissioned by the Office of Naval Research (ONR) to develop and construct a Cyclic Accelerated Corrosion Testing Machine. These machines at their core are a chemically neutral chamber which is capable of creating a highly corrosive environment. Samples of candidate materials for corrosion prone environments are placed within the chamber and exposed to concentrated salt, acid, or other corrosive elements in the form of a mist spray. This is intended to simulate their degradation patterns over their potential decades of exposure to natural corrosive elements in the course of a few hours or days to aid with material and coating selection.

Early designs principally revolved around varying arrangements and materials of the test chamber. The first design concept was top-loaded as is the current standard for corrosion chambers. However, in our ambition to create a more homogeneous spray distribution within our chamber we determined that our spray nozzle should be high in the chamber, impeding top loading. Accordingly, the second design concept resembled an industrial dishwasher, which allowed for excellent accessibility to samples but had flaws as well. This configuration would have provided ease of use, but added complexity to the chamber, and the lifting pistons necessary for this design could not be sourced in corrosion resistant materials.

The final design was dubbed the “Tri-Layer Oven” in the prototyping stage. The innermost

layer is a two by two by three-inch chamber of a 0.4 inch glass wrapped in one-inch silica fiber insulation. External to this layer are two support system closets, containing fluid storage, fluid processing, and controls hardware. The outermost layer is a painted tube steel cage covered with acrylonitrile butadiene styrene (ABS) polymer paneling providing a structurally sound corrosion resistant industrial exterior.

The fabrication process was broken into four subcategories: structural, electrical, plumbing, and

1. http://impact.nace.org/documents/Nace-International-Report.pdf

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thermal. The structure, a two by four by three-inch square cage of 1.25 inch tube steel, was welded together using one eighth inch 7018 stick welding material.

The electronics power supply system is below consisting of four 300 watt AC to DC power supplies capable of providing a total of 1200 watts of power to the chamber’s systems. Power routing is managed by a series of relays controlled by an Arduino MEGA microcontroller allowing users to program cycles of varying humidity, temperature, and corroding fluid flow. This functionality classifies our chamber as a “cyclic corrosion chamber.” The ABS electronics panel is utilized to provide a centralized and nonconductive control box.

The hydraulic and pneumatic system consists of a hydraulic loop to move corroding fluid and a pneumatic loop which injects wet and dry compressed air into the chamber to control humidity. The fluid-handling system consists of a 20-gallon storage tank to hold corrosive fluid, and a much smaller heated siphon tank, which is automatically refilled

when low to maintain a consistent height for the siphon fed nozzle.

The thermal system is composed of two components: a condenser drain for cooling and dehumidifying exhaust gases and our in chamber heating elements. The condenser drain is a heatsink where compressed air is sprayed over a series of corrosion resistant 954 bronze tubes through which exhaust gasses from the chamber flow.

Team LRDZ utilized ANSYS, a computational fluid dynamics (CDF) software to conduct finite element analysis of the chamber. 2D and 3D simulations of the chamber were completed to analyze heat flow. The analysis aided the team in the proper selection of a heating system and with the final system capable of bringing the air in the chamber to 140-degrees Fahrenheit within a minute.

The testing chamber is fully programmable, allowing users to pre-program custom schedules of humidity, temperature, and flow rates through our custom graphical user interface.


Team DewPointeTEAM MEMBERS: Peter Aram (team lead), Kyle Mummau, Jin Gam Park, Chris Smith

SPONSOR: Office of Naval Research (ONR)

FACULTY ADVISOR: Dr. Mehdi Amiri

ACKNOWLEDGEMENTS: Dr. Anisur Rahman, ONR; Mr. Johnnie Hall IV, and Dr. Nathan M. Kathir, GMU

Team DewPointe

Accelerated Corrosion Test Chamber

CORROSION AS A CONCEPT is one that is relatively simple to understand; if you are acquainted with rust on a metallic surface, you have encountered corrosion in its most raw form. Corrosion affects all metallic elements in a manner that is still not yet fully understood, costing the maritime

industry an estimated $2.5 trillion annually in prevention and repairs according to NACE IMPACT. Failure to identify the root of corrosion, or even how a specific material corrodes, can result in ultimate failure of the material during use. This could lead to catastrophic failure that would ultimately be exorbitantly costly for the operator. The Office of Naval Research in conjunction with the Navy Naval Air Systems Command at Naval Air Station Patuxent River invited Team DewPointe to join in the challenge of developing an Accelerated Corrosion Test (ACT) chamber that more closely mimics real-world conditions to test how a material will corrode during use, in order to better predict lifetimes and repair cycles.

Proposed Designs and Ultimate Design Selection CriteriaIn order to meet the design requirements that were given by our sponsor, while also being feasible with the time and resources allotted to us, Team DewPointe designed one overall chamber with three different designs for each component, for a total of 12 unique component designs. The team determined that it would be feasible to choose one overall design for the chamber, which worked out to be a cube with an A-frame roof, and then design the components that would maintain the environment required based on that (Figure 1). This resulted in a variety of designs spanning the spectrum in cost, efficiency, and efficacy. These designs were then ranked against a list of design criteria weights provided by the sponsor in order to determine the best design.

The ultimate design was capable of cyclic testing, where different environmental conditions were applied and varied in a cyclical manner. It consisted of a double-walled chamber with a heating element between the two walls to heat the interior. There would be a venturi exhaust system so that all the gases inside the chamber could be scrubbed of any corrosive elements and then freely released into the exterior environment during the dry cycle, allowing for safe use in laboratory environment. A system for altering humidity while holding temperature constant was also designed using a combination of

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fans and hydraulic nozzles which from all research appears to be a novel concept.

Fabrication StageThe final design was composed of multiple systems fabricated simultaneously to ensure completion on time. We planned to first fabricate the components that require long fabrication time while completing those that were less time-consuming next. The entire process utilized various machining techniques such as milling, welding, drilling, and tapping because the team worked with raw materials such as aluminum and brass. The double-walled chamber comprised of an interior aluminum cube enclosed by acrylonitrile butadiene styrene (ABS) proved to be the most difficult, as the aluminum was tungsten inert gas (TIG) welded into its shape. The team also designed a custom rack to hold test specimens in the chamber. To build the exhaust system, most of the fabrication was to be outsourced since it was

polyvinyl chloride (PVC) material in the shape of a venturi tube and there were not plastic molding capabilities available in the shop.

BenefitsPerforming corrosion testing at small scale with accurate results is a difficult task, which our team planned to address. Similar ACTs on the market tend to be expensive and take up large amounts of space whereas the team’s proposed deliverable has the advantage when comparing size and cost. The compact design is most beneficial when considering portability and space occupied while operating. Also, the chamber is comparably cost effective, totaling less than half the price of commercial chambers capable of cyclic testing. The designed chamber also provides capability of performing cyclic corrosion tests without lid opening, thereby operating safely in laboratory environment.


Team DATEAM MEMBERS: Samantha Pullman (team lead), Nauman Bhangu, Dylan Cahill, Sergio Ramos

SPONSOR: Vision Point Systems, Inc.

FACULTY ADVISOR: Dr. Erik Knudsen

ACKNOWLEDGEMENTS: Mr. Efrain Arredondo, Dr. Michael McFadden, and Dr. Erik Knudsen, GMU

Team DA

Autonomous Paint Application & Quality

Detection System

AUTOMATED PAINT APPLICATION TECHNOLOGY has been around for a while, but is proprietary, expensive, and not easily applicable to many military platforms. The application of paint to these components is a critical process, which traditionally is monitored by a human

technician applying the paint, and subsequently testing the thickness in a few random locations. Current automated systems are not designed to “see” the target and adapt their spray patterns to achieve a desired application thickness. As a result, Vision Point Systems, Inc. has tasked Team DA with the development of a proof-of-concept test apparatus to apply paint and sense the thickness and quality of said paint application in real time.

Alternative Design Concepts, Evaluation, and SelectionThe team was advised that hand-held spray equipment could be adapted to provide feedback to the operator and QA personnel, in order to visualize the applied coating thicknesses on a given piece of equipment. Given the ultimate desire of this project was to advance the capability of spray equipment to include an estimate of how much paint has been sprayed onto an arbitrary target, the team chose to integrate an existing paint sprayer into their design. During the fall semester, Team DA selected three design alternatives for the system which were analyzed for structural stability, cost, and modularity. This ultimately led to the selection of the final solution, which was chosen for its low-cost, low center-of-

gravity design. By utilizing existing components such as pre-fabricated linear belt-drives and an Arduino ATmega controller board, the team was on track to a low-cost, easily replicated system that accomplished all design goals. The prototype sensing and painting systems underwent rigorous testing and analysis.

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Final Design DescriptionThe final design includes a tri-directional gantry with ball screw driven linear guide rails in the X and Z direction for stability and precision, and a belt-driven linear guide stage in the Y direction for increased speed. This allows the system to stabilize the most sensitive components (the sensor and paint applicator), while allowing the paint target to be translated quickly by the stage. The gantry is controlled by an Arduino controller board that directs not only the motion and positioning of the gantry, but also controls the spray pattern of the paint applicator, and interacts with the sensor to correct paint defects by identifying areas of inconsistent paint application and directing the gantry to reapply in the specified location.

Fabrication DescriptionThe design benefits from almost all components being pre-fabricated, which leads to faster construction times. Some non-critical components were designed to be 3D-printed to reduce the overall cost of the system and allowed the team to fabricate custom parts for items such as magnetic covers for easy cleaning after use of the system. The gantry consists of pre-machined aluminum extrusions, and the guide rails were purchased from companies who specialize in manufacturing precision components. Overall, this allows for the design to be easily fabricated while also reducing the time and money required for maintenance and repairs.

Analysis, Modeling, and Testing ResultsThe developed gantry was analyzed using Autodesk Inventor, fluid mechanics analysis calculations were done using closed

form expressions, and all coding was done with Arduino. The key parameters that were modeled during full-scale testing of the system included mechanical stability and modularity, accuracy of the paint sprayer and sensor, and power consumption.

Discussion of Performance ResultsFull-scale testing of the paint sprayer revealed that through the paint thickness would vary in a range of approximately 50 micrometers. When test plates were measured, graphed, and averaged, there were distinct areas of layering that could be displayed to the user and analyzed for defects, allowing the Arduino to identify regions of undercoating and direct the paint sprayer to recoat any imperfections. Full-scale motor test results showed that these components were powerful enough to move the system to an exact location specified by the user, while reducing vibrations to the sensor and sprayer. The laser triangulation sensor was tested for accuracy and was found to be extremely sensitive to changes in thickness of paint applied to the aluminum test plates and graphed them with extreme accuracy. Further testing is needed to integrate the paint sprayer and sensor to the gantry for a fully autonomous system.

BenefitsTeam DA’s design is very affordable compared to similar autonomous painting system with no sensor equipment or size variability, where the cost including installation could exceed $100,000. Team DA has provided an outline for a future highly repeatable solution that offers modularity, ease of cleaning, low cost, and highly accurate results.


Team PHILTEAM MEMBERS: Kevin Arellano (team lead), Matthew Farnsworth, Robert Keenan, Danielle Maynard

SPONSOR: George Mason University—Patriot Green Fund (GMU—PGF)


ACKNOWLEDGEMENTS: Ms. Sarah D’alexander, Ms. Zhongyan Xu, and Prof. Elisabeth Lattanzi, GMU; BAE Systems (Chassis Fabrication)

Team PHILPortable Hazard Imager and Locator

Patriot Green Fund Infrastructure Improvement

Project (Thunder Rat II)

GEORGE MASON UNIVERSITY Facilities Management sought to inspect and preserve the existing storm drain infrastructure using robotic inspection to identify deterioration in the pipe systems on campus for sustainability. A student team from a previous year built a robotic

corrosion detection system to meet this need. In subsequent years the model experienced internal water damage, battery corrosion, and maintenance difficulties. Team PHIL was tasked with improving the existing model to make it watertight, durable, and easier to transport and operate while fitting into a 12-inch pipe.

Alternative Design Concepts, Evaluation, and Selection Three design concepts were created for the customer’s consideration. All designs used a Raspberry Pi (RPi) as its internal computer system, tethered to the user using an ethernet cable, rotated the camera 360 degrees using two servo motors, and improved waterproofing.

Design A was chosen because the wireless camera decreased risk of water entry, GoPro had the highest quality image, and the tracks system was most efficient for driving over obstacles/absorbing impact from falls. Additionally, the GoPro has a removable battery allowing the user to only replace its battery (not the entire camera) when it reaches the end of its lifecycle.

Final Design DescriptionThe final system uses tracks powered by two motors. The chassis was fabricated and painted for corrosion resistance by BAE Systems. The lid was sealed using a rubber gasket and 14 sealing screws. All motor entries were sealed using rubber gaskets, and the ethernet cable entered the internal circuit using a waterproof connection. The camera was placed in a commercial case mounted to two L-brackets, which rotated it 360 degrees using servo motors.

The internal circuit was designed to sustain at least 1 hour of battery life, assuming the user operated the robot at its maximum current draw 50 percent of the time, and at minimum current draw all other times. It had two batteries (one to power the RPi, the other to power motors, servo motors, and lighting). Batteries each had their

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Component Design A Design B Design C

Camera GoPro Camera Raspberry Pi Camera Module Raspberry Pi IR-CUT Night Vision Camera

Robot Software Commercial Camera Suite Customized Python Code Customized Python Code

Movement System Tracks Wheels Tracks

# of Motors 2 4 2

Pros Wireless camera; chassis entry points for water are limited.

Most similar to the previous model, more space in chassis.

Night vision camera quality is unpredictable.

Cons Use of the GoPro may be dependent on functionality of Camera Suite.

Hard-wired camera produces waterproofing difficulties.

Hard-wired camera produces waterproofing difficulties.

own power button switches. There were two charging ports accessed on the outside of the chassis. The GoPro has its own charging port and charger.

The robot received user commands via Xbox controller, hard wired to the external computer, which was hard wired to the internal RPi using an ethernet cable. The GoPro Hero 5 Camera communicated to the RPi inside the chassis wirelessly using RPi Wi-Fi capability. The Camera Suite package was unsuccessful so Python code software was developed for the user interface.

Discussion and Challenges in FabricationThe chassis is a constrained space, which students struggled with when internal circuitry needed alterations. Research indicated batteries in parallel discharge irregularly and corrode each other. The team chose to separate the batteries and give them separate charging and power buttons. Mechanical testing and fabrication were based around the timeline for fabricating the chassis so the overall fabrication schedule required flexibility.

Analysis, Simulation, Modeling, and Testing ResultsTorque on the tracks (and thus on the motors) was calculated theoretically and used to project the speed of the system in wet and dry concrete conditions (with accepted frictional coefficients). The battery life was calculated by theoretically

determining the current draw of all components. Finally, the projected maximum distance the robot could travel was determined using the theoretical battery life and projected speed.

Testing results revealed theoretical calculations were slightly off due to discrepancies in expected chassis weight versus measured chassis weight. This altered the expected torque value which affected all following calculations. The testing results found most values to be less than the theoretical values.

Discussion of Performance ResultsTesting results indicate the system will perform with a minimum travel distance of 1,400 feet, speed of 0.7 feet per second in wet conditions and 0.6 feet per second in dry conditions, and battery life of at least one hour. All user requirements were met.

Conclusions, Benefits, and ApplicationsThis system allows for observation of slow drain deterioration, potentially reducing structural repair costs. It allows users to create assessment practices while the drain system maintains its bulk integrity. The tethered observation circuit layout also sees applications in situations that convey information to the user from a restricted space (for example underwater).


Team AutoLineTEAM MEMBERS: Albert Ujevic (team lead ), Sam King, Drake Moretz, Jacob Sanders, Will Smith

SPONSOR: TTM Technologies, Inc.


ACKNOWLEDGEMENTS: Ms. Peggy LeGrand, Mr. Jhonatan Lavayen, and Mr. Robert Link , TTM Technologies, Inc.

Team AutoLine

Printed Circuitboard Accumulator

TTM TECHNOLOGIES, INC. was looking to automate their manufacturing process of printed circuit boards (PCBs) for systematic handling and delivery within the production facility.

Previously, a majority of the production lines were loaded and unloaded by operators which carried the risk of human error in handling these expensive and delicate products. Through integrated automation, TTM will be able to reduce the number of panels scrapped, saving both money and materials. Some of the conveyor lines contain accumulators that collect and release PCBs into the machines. These accumulators are very expensive and have long lead times for installation. TTM aimed to commercialize their own accumulators to be implemented within the production facility.

When developing various distinct designs, the deciding factors between each concept were the drivetrain, complexity (both to build and to use), and price. The proposed methods for transmission were a series of connecting gears or using a chain and sprocket to rotate the shaft. Additionally, the preferred design would have the least amount of moving components to ensure simplicity in the fabrication of the machine as well as the operation and maintenance of it. Naturally, striking a balance between budget and functionality was important as well.

The final design utilized the gears since they proved to be the preferred choice as it had less points of failure than the chain and sprocket. The gears also translate higher torque and save space. The overall drivetrain consisted of three rotary shafts that the chains would rotate around. Having three shafts would reduce the slack in the chain and slippage around the sprockets to keep the

motion consistent. A conveyor belt is placed on the front of the accumulator to allow the products to be collected and distributed from the production lines. On this conveyor, sensors are used to align the panels for the accumulator to grab/drop them safely.

The main challenge in the fabrication process has been keeping the drilling uniform. The accumulator contains shelves that are used to hold the products. Each shelf is made up of an ABS bar with four threaded rods drilled into it and an aluminum L-bar attached at the bottom. It is vital that the holes are drilled in the correct location to keep the alignment consistent with the chains. Errors in these holes could result in defective performance.

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Due to the number of shelves that the accumulator holds, it was essential that they were able to withstand the maximum load of 15 pounds. Testing of this assembly consisted of clamping the shelves to the side of a table and applying various loads while measuring the displacement. TTM provided Team AutoLine with blank panels to perform this testing. This experiment would be repeated multiple times with various alignments of the panels. As a result, the shelves were able to withstand all of the loads. Furthermore, testing on the software needed to be evaluated as well. Each electrical component was analyzed individually to ensure that the wiring was properly handled. After they had been assessed, certain scenarios (i.e. emergency stop, panel overload, manual control, reverse direction) were performed to make sure the controller executed the commands as planned. Finally, all of

the elements would then come together to verify that the logic had been programmed appropriately.

Upon assembly of the prototype, all applications of the product were tested and verified. Once it was determined that the accumulator could properly load and unload panels of the designated maximum weight, and that the software could direct the machinery as it was meant to, the product was deemed complete and the project successful.

Considering how much designing, simulation, testing, and redesigning occurred prior to building the prototype, it should be no surprise that the project was ultimately successful in spite of multiple setbacks. Should TTM choose to make use of this product, they will have a method of further automating their PCB production lines that costs less, ships faster, and maintains more easily than currently available options.


Team VIPERTEAM MEMBERS: Rachid Karame (team lead), Moises Angulo, Hannah Ferrante, Christian Reiter

SPONSOR: Vision Point Systems, Inc.

FACULTY ADVISOR: Prof. Gino Manzo

ACKNOWLEDGEMENTS: Dr. Michael McFadden, Dr. Nathan M. Kathir, Dr. Erik Knudsen, and Ms. Ardiana Brahja, GMU; Mr. Wayne McGaulley and Mr. Jeff O’Dell, Vision Point Systems, Inc. (VPS)

Team VIPERVersatile Inline Pipe Examination Robot

Versatile Inline Pipe Examination Robot (VIPER)

THE LIFECYCLE OF UNDERGROUND STEEL PIPELINES is often shortened by the corrosive environment around it which warrants the need for protective exterior coatings. The methods currently employed to detect coating anomalies in underground pipelines can be extremely

cumbersome and require expert personnel to manually conduct inspections stretching over hundreds of miles. Vision Point Systems, Inc. (VPS) has sought to develop an innovative solution for pipeline inspections by tasking Team VIPER to design and fabricate a prototype for an autonomous inline inspection device, capable of navigating inside a pipe and examine its outer coatings by utilizing four-wire current mapping, thus eliminating the need for any initial excavation or manual surveying. By running a high current within the pipe’s metal, four-wire current mapping can detect coating abnormalities by measuring the varying voltage drops due to coating defects on that metal.

Alternative Design Concepts, Evaluation, and SelectionDuring the 2019 Fall Semester, Team VIPER finalized three preliminary prototype designs for the Versatile Inline Pipe Examination Robot (VIPER), offering various models of operation and design configurations. The three designs displayed a range of mechanical, structural, drivetrain, sensor, and data collection concepts. The first two concepts combined an autonomous four-wheel robot design, fitted with Omni-wheels to facilitate 90-degree turns within the pipeline. The first one operates wirelessly and carries a four-wire current mapping sensor package. The second design is powered by an auxiliary source and incorporates an open loop circuit sensor that

would close due to a coating failure that releases a stray current. The third prototype carried the same current mapping sensor package as the first prototype, but had a tank tread drivetrain concept, which was designed to be wirelessly controlled due to the complexity of autonomously navigating turns and corners with tank tracks.

By the end of the Fall semester, and after consulting with the sponsor, technical advisors and industry professionals, Team VIPER finalized its decision to move forward with developing the VIPER I prototype and started to further improve its design details and controls configuration in order to offer optimal maneuverability and detection accuracy.

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Final Design Description VIPER I’s chassis is built around an off-the-shelf UNIROI Robot frame. The device is able to accommodate a custom Arduino UNO configuration (a microcontroller board used to program and automate the vehicle) to operate both the navigation and four-wire sensor package.The Arduino controls the motors powering all dynamic elements of the robot. The sensor package, which is housed in a custom designed 3D-printed enclosure structured around the chassis, consists of a system integrating a separate current source, multimeters, a data logger and a servo operated scissor lift designed to safely deploy the sensor probes onto the pipe’s interior bare metal surface. The sensor’s operation model is programmed to measure voltage drops via a stop-and-go movement. The system also incorporates an odometer built through an encoder, providing the location of the robot in the pipe based on the distance traveled. The Arduino can register and combine the information transmitted by both the odometer and the sensor and use their common timestamps to generate a set of data that allows the user to identify the accurate location of coating defects.

Discussion and Challenges in FabricationThe fabrication began with assembling the chassis and drivetrain, verifying its functionality and configuring the control systems. The team also conducted alterations such as material upgrades, motor parts replacement, and microcontroller reprogramming. To facilitate maintenance, the 3D-printed parts of the enclosure were geometrically designed to allow easy access to all subsystems of the robot once fully assembled. In addition, various types of 3D printing resin were tested to match the right 3D material with the right part, depending on its function. Another challenge that the team faced was selecting testing material. Currently in the field, four-wire current mapping is conducted by running high amounts of currents along the pipeline, reaching up to 10A, in order to detect electrical interferences that result from coating defects. Due to the hazards that high currents may cause, the team limited the sensor testing to 200mA, all while using appropriate PPE. At 200mA, no voltage drop could be detected across a corroded section of a 12 inch steel pipe due to the extremely low electrical resistance of its metal. To get around that, the target test specimen was scaled

down to a thin gauge metal wire. The team researched and explored the properties of multiple metal types under various environmental conditions, acquired a variety of test samples and tested their resistivity based on the gauge sizes. After conducting trials on stainless steel, copper, tungsten and other types of metal samples of various cross sectional areas, it was found that a 38 gauge Manganin wire (Cu 84 percent, Mn 12 percent, Ni 4 percent) displayed the most adequate experimental results.

Analysis, Simulation, Modeling, and Testing ResultsA finite element analysis (FEA) simulation was conducted on the sensor package enclosure to verify its structural integrity. The FEA results show that the lowest safety factor is 4.39 at the bottom axle hole of the scissor lift, which occurs when a 4lb bearing load is applied to simulate the force of the lift being pushed against the pipe wall.

Before incorporating the final sensor design with the entire system of the robot, a series of four-wire current mapping tests was conducted on a 40-centimeter Manganin wire to verify the validity of the test. While going through a five-day accelerated corrosion cycle, the sample was tested at the beginning, in the middle, and at the end of the cycle. The four-wire test results clearly displayed a gradual increase in voltage drops across the wire as a result of the increase in resistance due to corrosion, therefore verifying the team’s testing approach.

Conclusions, Benefits, and ApplicationsThe prototype that Team VIPER has designed serves as a proof of concept of the ability to detect exterior coating anomalies on pipelines – to include delamination, disbondment, corrosion, cracks, etc. – through the use of four-wire current mapping from within the pipe. If further developed to incorporate a multi-robot system stretching over miles of underground pipelines, this project has the potential to save the pipeline industry’s valuable resources and labor costs, as well as make pipeline inspection operations safer and more user friendly.


Team PairaMaxTEAM MEMBERS: Josue Arana (team lead), Nasser M. Almaki, Lily Patterson, Kaiyao Xie

SPONSOR: QL+

FACULTY SPONSORS: Dr. Nathan M. Kathir and Dr. Shri Dubey

ACKNOWLEDGEMENTS: Dr. Robert D. Wolff, QL+; Mr. Alex Lee, Challenger; Mr. Johnnie Hall IV, Mr. Sandor Nyerges, and Dr. Daniel Lofaro, GMU

Team PairaMax

Backpack Chair

TEAM PAIRAMAX was given the task of creating a device to assist a disabled veteran to help him facilitate various activities outside his home. The initial meeting with the veteran and the program manager for QL Plus, clarified that their vision included a portable chair design, something which

could be automatically deployed, quickly and comfortably, from a storage compartment about the size of a backpack.

Alternative Designs and EvaluationIn the development process, Team PairaMax produced a number of different alternatives which served to guide our selection for the ultimate design. These designs were all evaluated by several metrics: cost of production, comfort, core and peripheral function, durability, and weight. The initial designs produced by the team loosely fulfilled these criteria, and successive designs largely made up these incongruencies. Through the process of our iterative tests, our team determined that our initial material suggestion was over-engineered for the design, and that parts made of proposed steel and titanium were too heavy or expensive, as well as being too mechanically sound, to be practical to use in the design. As such, the team decided to switch the majority of the components of manufacture to aluminum, a lighter weight, less expensive material that could still withstand the chair’s normal loading. For the mechanical components of the chair, our team considered several alternatives, including telescoping hydraulic or pneumatic legs, as well as scissor joints, before determining that linear

actuators would be the best solution for this problem. Since these were added weight to the system, we minimized the quantity of their use in the ultimate design, guided by our adherence to weight, stability, and strength in our decision-making process.

Final Design DescriptionThe team’s final backpack chair design consisted of the following: a mechanical system comprised of two linear actuators made by Progressive Automation, which served as leg and chair deployment, a control system, compatible to the actuators, allowing presets for their deployment, and a structural design, including the frame and all other components. Several critical parts for this design required collaboration with an outsourced manufacturer, including the foot, seat brackets, and seat bar. This allowed the team to complete the project within the time constraints set by Mason.

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All contact surfaces are padded for comfort, and the system is powered by a portable battery, which will sustain the product’s use time between charges for a full day. These components would be enclosed in a weatherproof, high-hold capacity shell of a hiking backpack.

Other components to the main core of the chair mechanism include the armrests and other accessories. The armrests were a point of lengthy discussion amongst the team, and it was ultimately decided that a manual armrest apparatus be used instead of an automated one, due to the technical and functional constraints such a system would pose. The addition of armrests, however, provided the team a convenient location to provide crutch holders to the customer, which would free up the user’s hands while sitting. The team did their best to provide as many of the accessory features as possible, as requested by the veteran, tailoring the finished product to his specifications.

Analysis, Simulation, and Modeling Our team has, throughout the design process, ran simulated stress tests on every design to ensure they would withstand everyday use. We used Autodesk CAD simulation software to determine the relative safety factor of each part and to visualize which areas required further design modification. Due to the mechanics of the system we designed, the seat bar and brackets proved critically stressed in our designs, so we made special assurances that these parts would not fail. These stress results were obtained through finite element analysis and led to the overall reduction of weight of the system and the strengthening of critical points. Working with a safety factor of larger than 2.5, our team is confident in the safety of this design.

In choosing the specifications for our actuators, our team determined the critical factors in our decision to

be the weight, force, and speed of actuators. To allow the largest function of our project, the force needed to lift, and minimization of the deployment time were indeed critical to ensure customer satisfaction in which both our actuators surpassed these constraints.

Discussion of FabricationThe parts that have been used to fabricate the project consist of three main components: the frame, the seat bar, and the foot. The frame was built using aluminum 6061, a band saw for cutting, and an arc welding machine (Syncrowave 250 DX/350 LX) for welding it together. For the seat bar, aluminum 5052 was used, as well as a bandsaw (28 inch throat capacity) for cutting and a Bridgeport machine (vertical Mill VM-949E-VS) for milling. The foot process was only reached to the simulation phase through CAM fusion and would have been made out of aluminum 6061, and a Tormach CNC machine (Tormach 770M+) would have completed the manufacturing.

Concluding StatementTeam PairaMax engaged with the process of designing and manufacturing a product to the specifications of a problem statement, of iterating on those designs to provide maximum fulfillment, and to utilize all good and necessary engineering practices to create a deliverable that is useful, operable, and safe.

Although our team is unable to complete the manufacturing process at this time, our designs and prior manufacture will be a testament to our team’s diligence and hard work on this project, and our sincere effort to the completion of the project deliverables. Our team is proud to have worked with QL Plus to assist a veteran and will continue to support them and their work.


Team CHARIOTTEAM MEMBERS: Mark Foss (team lead), Joey Dunleavey, Edgar Flores, Dexter Hubbard

SPONSOR: QL+

FACULTY ADVISOR: Dr. Ali Beheshti

ACKNOWLEDGEMENTS: Dr. Robert D. Wolff, QL+; Mr. Johnnie Hall IV, and Dr. Erik Knudsen, GMU; Major Peter Way, Challenger

Team CHARIOT

Handcycle Modification Project

THE HANDCYCLE MODIFICATION TEAM , also known as Team CHARIOT, was tasked with improving the comfort and performance of Army Major Peter Way’s handcycle. Major Way experienced limited mobility of the prosthetic cup on the right side and severe pain in his left knee

after riding the handcycle for extended periods of time. Accordingly, the team concluded that it was necessary to significantly alleviate the pain in his injured left knee and upgrade the handcycle with new hardware.

The largest sources of discomfort were the angle of the left knee tray, the mobility of the prosthetic cup, and the underpowered petal assist motor. These three grievances were the driving factors in the team’s designs. Since these factors required separate solutions, the team created multiple solutions for each problem which were narrowed down to the optimal combination of improvements that satisfied the challenger’s requirements.

The preliminary solutions included: a footrest that would allow the challenger to take pressure off his injured knee, two designs for a saddle to distribute the challenger’s weight from his knee to the handcycle’s frame, a rack system that allows the challenger to adjust the lateral position and angle of the existing knee tray, a rod end bearing (heim joint) connecting his prosthetic cup to another rack system that provides lateral adjustment and a full range of motion, and two potential locations to install a more powerful mid-drive motor (in the front of the vehicle or in the middle). To narrow down the solutions the team used numerical finite

element analysis, discussions with the challenger, sponsor, and advisers as well as cost analysis to determine the combination of solutions that comprised Team CHARIOT’s final design.

Rack systems were designed which adjust the positions of the knee tray and prosthetic cup. These racks were fabricated from aluminum 7075 to minimize the added weight to the vehicle while maintaining high strength. The left and right racks had several possible configurations.

The mid-drive motor was installed in front of the vehicle. This more powerful motor replaced the existing rear wheel pedal assist motor and allows the challenger to ride longer with less fatigue. Finally, out of two initially considered saddle options, the team developed an ergonomic design that presented several manufacturing challenges due to its complex shape. The saddle was cast in fiberglass, padded with impact resistant foam, and

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covered in a layer of marine vinyl to provide a tough, water-resistant covering.

The first challenge in fabrication was attaining rigorous and prolonged training in several manufacturing processes. Additionally, no one on the team had experience with fiberglass casting so we took it upon ourselves to learn how to implement this manufacturing technique. Significant self-learning and iterations were needed to cast the fiberglass in the desired shape. This further strained our timeline, but proper planning enabled the team to stay on schedule by tackling both the fiberglass and metal work concurrently. Thanks to our strong team dynamic and dedication from each team member, we were able to surpass all our challenges and made considerable strides in delivering our project with the quality it deserves.

To ensure that Team CHARIOT’s design would survive multiple years of use; a generalized dynamic analysis of the worst-case scenario for the handcycle was created to model the maximum possible acceleration that the handcycle may encounter. This maximum acceleration was applied to the handcycle in a point-mass analysis. The maximum force expected on the handcycle was then applied to each of the components of the stress and strain analysis using a finite

element simulation. The results of the simulation showed minimal deflections for each of the parts, proving that the adjustment racks may have been overbuilt; however, the added weight was minimal due to our usage of aluminum. Additionally, using the aforementioned data: infinite life fatigue analysis for bending stress analysis, and contact forces at joints were conducted on all metal components to examine and verify the structural integrity of our designs.

With the new design, the weight of the handcycle is only increased by 15 percent while drastically improving the power output of the motor. The motor was upgraded from 400 watts to 1200 watts which will allow the vehicle to travel up inclined planes at twice the previous maximum speed. With the better weight distribution of the saddle and the improved battery life, we envision the challenger to comfortably ride for at least four continuous hours.

In conclusion, these modifications would help our challenger better pursue his passion of handcycling by allowing him to comfortably ride for longer periods of time. Since our improvements are adjustable, we envision that this system can be used as a model for other handcycle modifications to anyone in a similar situation to Major Way.


Team SEADTEAM MEMBERS: Andrew Baskin (team lead), Ramez Atta, Daniel Colbert, Mark Malkoun, and Pedro Malpartida

SPONSOR: QL+

FACULTY ADVISOR: Prof. Gino Manzo

ACKNOWLEDGEMENTS: Dr. Robert D. Wolff; Mr. John Simms and Mr. Jack Simms, HomeValet, Inc.; Mr. Johnnie Hall IV, Dr. Erik Knudsen, and Dr. Nathan M. Kathir, GMU

Team SEADSecure Efficient Accessible Delivery

Design and Fabrication of a Home Delivery Receptacle

IN TODAY’S WORLD , more people rely on online shopping than ever before. Anything from medicine, to consumer products, to perishable goods, can be bought with just a click of a button. However, given all the ease, there are a number of problems that must still be addressed in the online shopping world

when it comes to deliveries. Packages left outside are susceptible to theft by porch pirates, spoilage if left out too long, or might even require a signature before it can be delivered. People with disabilities often find it stressful to reach the door in time to accept these deliveries. To solve this problem, Team SEAD has been tasked by our sponsor, Quality of Life Plus, and challenger, HomeValet, Inc., to design, fabricate, and test a prototype for a home delivery reciprocal that is secure, efficient, and accessible for people with disabilities.

The first semester primarily consisted of research and design of potential prototypes. The overall design consisted of three compartments: freezer, refrigerated, and ambient. The freezer and refrigerated compartments are temperature controlled using a micro compressor refrigeration system, a cold plate (or evaporator), and an Arduino control system. The compartments can be raised using a scissor jack lift system to make it more accessible for people with disabilities. All of which is enclosed by an exterior shell and a lid that houses most of the electronics. Enclosed in the lid is a camera to take pictures for proof of delivery, locking mechanism (manual and automatic), fans for circulating the cold air, and the Raspberry Pi with stored software.

Many alternative designs were proposed.

When designing the cooling system, one of the most important features was selecting the right compressor. Different compressors were considered for this project, such as hermetically-sealed compressors and rotary compressors. The variable speed rotary compressor was best suited for this application due to its small size, capacity, and variable output.

Another crucial component to the cooling system was selecting an evaporator that was small so that delivery space was maximized in the freezer but also had the capacity to absorb the required heat load.

As for the lift, various design discussions

Problem Definition



focused heavily on what mechanism would be used to drive the lift system. Electric motors and pneumatic air springs were taken into consideration, but careful analysis showed that linear actuators were the most cost efficient and reliable method of driving the scissor jack.

Following the CDR presentation, several design changes to the final product were made prior to fabrication. The exterior now has an aluminum frame covered in acrylic rather than very thin stainless steel to increase the product’s impact resistance. The lid thickness was reduced and one large fan to drive air from the freezer to the refrigerated compartment was replaced with two smaller fans.

The UPS, in the case of a power outage, was replaced with a smaller one that fit into the lid, while the camera, locking mechanism for security, a light strip for illumination, and an LED indicator light to show the state of the Smartbox (locked or unlocked) had design changes. The exterior frame houses the inner compartments and micro compressor unit, which are placed on the upper platform of the scissor jack lift system, that is driven by linear actuators.

Upon the completion of the machine shop training, and approval of our final design, the first order sheet for materials was placed and fabrication began. Both the interior compartments and the lift system were being constructed in parallel. The interior fabrication began with meticulously cutting to shape polystyrene insulation for the compartments and high-density polyethylene (HDPE) sheets to line the insulation. Once all the polystyrene and polyethylene was cut to shape, the HDPE sheets were glued to the insulation.

As Team SEAD progressed in the assembly process a few new problems were encountered. One of the biggest

problems was that the initial location of the cooling unit prevented proper airflow for the heat rejection from the condenser. Adjustments were made, and the unit was relocated outside of the compartments. However, to facilitate this change while maintaining the exterior dimensions, the interior compartment dimensions were decreased. These modifications allowed for the proper ventilation and functioning of the cooling system while adhering to the space requirements requested by the sponsor. Another difficult fabrication step was cutting to shape the swinging cabinet doors for compartment access.

The fabrication of the lift and frame began after the aluminum tubes were delivered. The frame was constructed of one inch by one inch rectangular hollow bars and the lift system out of two inches by one inch hollow bars. Circular rods with a diameter of three quarters of an inch were used to construct the scissor jack and bearings were connected at the ends to act as wheels.

The main challenge faced while constructing the lift system was the placement of the linear actuators. An analysis helped determine the optimum positioning of the actuators. The mounting location was then determined which enables the lift system to extend to a height of 18 inches.

Team SEAD hopes that the HomeValet Smartbox paves a new road for innovation in the world of online shopping. Homeowners, senior citizens, disabled veterans, and other people can rest assured that their packages, groceries, and medications are secured and stored appropriately. We hope that this is just the beginning and technologies can be built off the back of this prototype that give rise to even greater innovations in the commercial delivery industry.


2020 Senior Design Project Faculty and StaffThe student teams thank the faculty and staff for their support,

mentoring, and dedication throughout the year.

INSTRUCTORS

Dr. Nathan M. KathirDirector of Senior Projects

and Course Instructor

Dr. Erik KnudsenCourse Instructor

FACULTY ADVISORS

Rogelio C. Agbanlog Dr. Mehdi Amiri Darehbidi Dr. Ali Beheshti Dr. Pei Dong

Dr. Shri Dubey Prof. Gino Manzo Dr. Leigh McCue

CRITICAL SUPPORT STAFF

Ms. Jeanene HarrisAdministrative Specialist

Ms. Ardiana BrahjaFiscal and Budget Support Specialist

Mr. Johnnie Hall IVLaboratory Technician


Building Relationships, Shaping the FutureOur faculty members are determined to educate the best mechanical engineers in the business. You can make a difference by backing our research, helping us build and equip advanced laboratories, and funding student scholarships.

Please consider: ■ Partnering with students on their year-long senior design projects. Industry sponsors can support a team of seniors to help them conceptualize, design, analyze, build, test, and report on an engineering problem that benefits the sponsor.

■ Funding scholarships and financial aid for students, including those in the Mason-NOVA ADVANCE program.

■ Supporting students travel to conferences and national design competitions.

■ Covering the cost of our students’ first step in their journey to professional certification by paying for the Fundamentals of Engineering Exam.

■ Offering students internships and learning opportunities outside the classroom.

■ Equipping instructional labs and senior design space, including a new mechatronics lab.

■ Mentoring a student. ■ Sponsoring a lecture series or other event during Engineers Week.

■ Supporting faculty research. ■ If you want to make a bigger impact or honor someone special, consider a naming opportunity for our thermal fluids lab, teaching studio, or senior design space at the Science and Technology Campus.

Contact Michele Brumsey at [email protected] or 703-993-

6069 to explore all our giving opportunities and plan gifts in ways

that achieve our shared goals.

Now More Than Ever, Mason Students Need YouOver the past weeks, the impacts from the coronavirus outbreak have turned the lives of thousands of our students upside down. Our campuses have closed, classes have moved online, and everyone is feeling the uncertainty.

At this moment, many students lack the financial cushion needed to pay their rent or tuition, or even to be sure where their next meal is coming from. For these students, just a few hundred dollars can make all the difference.

Across the Mason community, people are asking, “How can we help? What can I do?” In response, University Life has established the Student Emergency Assistance Fund, aimed at getting much-needed assistance in the hands of Mason students now. Contributions to the Student Emergency Assistance Fund will be managed by the Office of University Life and will be awarded to the students with the greatest need, regardless of college or school affiliation.

Every donation will help a student in need—empowering them to succeed. Please consider making a donation to the Student Emergency Assistance Fund today at: giving.gmu.edu

Your gift to this fund will provide immediate financial

assistance and other resources to students facing an unexpected financial crisis that could derail their progress towards a degree.

Number of Students per Semester Since the GMU Department of Mechanical EngineeringStarted in 2014

Fall 2014 Spring 2015 Fall 2015 Spring 2016 Fall 2016 Spring 2017 Fall 2017 Spring 2018 Fall 2018 Spring 2019 Fall 2019 Spring 2020

136 138

223 233

324 325

372 369 378355

12

ACADEMIC YEAR 2014–15 ACADEMIC YEAR 2015–16 ACADEMIC YEAR 2017–18 ACADEMIC YEAR 2019–20ACADEMIC YEAR 2016–17 ACADEMIC YEAR 2018–19

Ethnic Breakdown, GMU Mechanical Engineering Students Compared with Mechanical Engineering Students Nationally

Gender Breakdown, GMU Mechanical Engineering Students Compared with Mechanical Engineering Students Nationally

GMUGMU U.S.U.S.

African American9%

Female13%

Male87%

Female14%

African American3%

Asian American8%

Hispanic American9%

Asian American15%

Hispanic American14%

White American44%

White American57%

Other23%

Other18%

Male86%

Number of Full-Time Faculty per Academic Year

25% of the Current Faculty is Female

2014–15

2015–16

2016–17

2017–18

2018–19

2019–20

15

13

9

3

3

Number of Graduates per Academic Year2014–15

2015–16

2016–17

2017–18

2018–19

2019–20

*Estimated

65*

55

37

7

1

NA

16

31


What Our Students Say

To me, mechanical engineers are useful in any sector, so I knew that the education I received at Mason would serve me in any career path I chose to follow. The department and faculty have gone to great lengths to make sure their engineers are prepared for real work environments, and their dedication to the success of their students is unparalleled.

—Samantha Pullman, Class of 2020

George Mason’s engineering department is a true testament to the success of its students. Not only do faculty provide individualized attention to pupils, but also facilitate an environment for personal growth through research assistantships and Capstone.

—Vineet Nair, Class of 2020

We are investing in new labs and spaces, and mechanical engineering majors were the first to use the new $1.8 million lab facilities that opened on Mason’s Science and Technology Campus in 2017.

For more information:WEBSITE: mechanical.gmu.eduEMAIL: [email protected]: 703-993-5383

Undergraduate Questions:COLIN REAGLE | [email protected]

703-993-1712

Graduate Questions:ROBERT HANDLER | [email protected]

703-993-3845

“I chose to be a mechanical engineer because I wanted to be out of my comfort zone. The mechanical engineering department challenged me to think in an analytical yet people-centered way. Everything we are taught prepares us to make the world a better place with concrete, creative solutions. Professors have invested in my interests and given me valuable guidance that has helped me realize what I have to offer.”

—Danielle Maynard, Class of 2020

mechanical.gmu.edu 2020 Department of Mechanical Engineering Senior Design

Thank You to Our Sponsors and Supporters

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