assignment 1.pdf

UNIVERSITY OF CAPE TOWN

DEPARTMENT OF MECHANICAL ENGINEERING

MEC4103F PRODUCT DESIGN 2015

Assignment: Assignment 1 OPPORTUNITY FORMULATION AND EVALUATION OF

ALERNATIVES

1. I know that plagiarism is wrong. Plagiarism is to use another’s work and pretend that it is

one’s own.

2. Each significant contribution to, and quotation in, this assignment from the work(s) of other

people has been attributed, and has been cited and referenced.

3. This assignment is my own work.

4. I have not allowed, and will not allow anyone to copy my work with the intention of passing

it off as his or her own work.

Team member(s):

Surname Initial(s): Student number Signature

KRIEK S KRKSHA006

MASIKHWA M MSKMUL001

RAMSURAN SITARAM Y RMSYAS001

TURNLEY C TRNCHA003

Group number: 2 Date: 13 March 2015

1. Company Name 1.1. Company Logo and Slogan

Figure 1: Logo and slogan of Alpha Trailers

1.2. Company Description

Established in 2015, Alpha Trailers is a leading trailer company that specializes in designing and developing advanced, general multi-purpose trailers suitable for a variety of industries including, but not limited to, the logging, construction and agricultural sectors. Our vision is to continually develop trailers that do not only meet and exceed our customer’s expectations by incorporating efficient and modern, easy-to-use technologies, but also to make their lives easier by providing them with affordable consultation services in their designated fields.

1.3. Company Charter

Design and implement a functional, light trailer that is capable of lifting, securing and transporting a payload. The product is to be released by the end of 2015 through the company’s existing retail sales channel.

Spaceship & Rocket Trailers

Air Drone Trailer For Air Transport

Deep Sea Voyager Trailer

Submarine Trailer For Additional Supplies

Shallow Water Fishing Trailer

Commercial Trailer for Camping Supply Transportation

Industrial Trailer For Freight Transportation

A self-energising trailer with Battery Attachment for

converting Excess Trailer Energy to Electricity

A Hover-Trailer for attaching to Military Hovercrafts

A Film Trailer for housing talent on set

A Film trailer for holding vehicles when filming chase

scenes

A Trailer for the transportation of livestock

A Game Safari Trailer For the Transportation of People

A Game Safari Trailer

Crew Ship Trailer For the Storage of Safety Equipment

and Inflatable Boats

Trailer For Lifting Mining Equipment

Trailer For Lifting Timber after Logging

A Dump Trailer For The Lifting and Transport of

Refuse

Filter 1Time

Constraints


Shallow Water Fishing Trailer

Commercial Trailer for Camping Supply Transportation

Industrial Trailer For Freight Transportation



A Film Trailer for housing talent on set

A Film trailer for holding vehicles when filming chase

scenes


A Game Safari Trailer For the Transportation of People


Trailer For Lifting Mining Equipment



Refuse

Filter 2Suitability For Company

Size and Expertise








Refuse

Trailers For Inaccessible Area (Radioactive)

Trailer For Sports Field Injuries

Variable Height Trailer

Trailers For Inaccessible Area (Radioactive)



Variable Height Trailer

Airport Trailer (Luggage)

Concept Merge

Filter 3Market Size and

Consumer Environment



Animal Transportation Trailer



Airport Trailer (Luggage)

Variable Height Trailer Variable Height Trailer

2. Opportunity Identification 2.1. Opportunity Screening

Twenty-two opportunities were generated that aligned to the company charter. Three phases of screening were done according to the following criteria:

1. Time – Can the opportunity be launched within one year?

2. Scale – Does the opportunity align with the company size and expertise?

3. Market – Is the market worth pursuing within a Southern African context?

This allowed for the development of promising ideas, from which five exceptional opportunities were selected. The reflection of these opportunities is discussed overleaf.

Figure 2: Opportunity tournament for determining exceptional opportunities with representative product concepts

2.2. Exceptional Opportunity Classification

Five promising opportunities made it through the screening. These were developed further through competition and market segment analysis, Real-Win-Worth-It (RWW) analysis, possible subassemblies and derivative products. It was decided to limit the design process to Horizon 2 type opportunities, so as to align with the company structure and time constraints.

i) Functional trailer with self-energising (flywheel) battery

This concept uses rotating inertial mass of the wheels of a trailer to charge a battery. The electricity can be stored and discharged at a destination, and is envisioned to have maximum appeal in the camping market. However, the base concept does not perform a lifting function and borders too closely with a Horizon 3 type product, and so was discarded from the current design process and will be reconsidered as a future company platform.

ii) Animal transportation trailer

In Southern Africa emergency medical aid is often needed for injured animals on both game ranges and in the wild, especially for endangered species. These animals are often heavy and difficult to transport to off-site facilities, hence an animal transportation trailer would be able to aid in the removal and transportation process. However, it was determined that ultimately the transport of such animals constitutes a small market and weight restrictions would no longer constitute the trailer as light.

iii) Trailer for sports injury transportation

Current international sporting standards require any athlete with a suspected spinal injury to be transported by no less than 7 people if carried by a stretcher. An opportunity for a trailer exists such that it would lift a potentially injured athlete, and transport them safely off the field of play behind a motorised cart. Although this proved a potential solution to areas with low personnel, the opportunity was considered too expensive to compete with current solutions of handheld stretchers.

iv) Trailer for lifting timber after logging

Logging trailers are an already well-established product in the Northern Hemisphere, and particularly in the Americas. An opportunity for a logging trailer was identified for the Southern African region, where a trailer for lifting recently-logged wood would aid in the development of small businesses. The opportunity was considered promising and was decided to be undertaken as a future project.

v) Variable height lifting trailer

Some objects that are too heavy to lift, are easily transported if they are able to be wheeled on to the transportation bed. An opportunity for a trailer was conceived such that the transportation bed is allowed to lower to the ground, and raise again after loading. This opportunity was considered promising with little competition in the South African market, and with broad enough applications to be financially viable.

3. Product Planning and Mission Statement 3.1. Product Platform Development

Light variable-height trailer with winch system

Research and Technology

Development

Platform Product

Development

Derivative Product

Development

AgriculturalTrailer

General Consumer

Trailer

Flywheel based energy storage attachment

Time

Light duty add on

Heavy duty add on

Heavy duty crane operated winch system

Logging Trailer

Industrial Transport

Trailer

Construction Trailer

Project

Product Release

Figure 3: Platform development project of the family of products to be released by Alpha Trailers

3.2. Product Planning

Subsequent to the identification of exceptional opportunities it was decided that the opportunity of a Logging Trailer offered the greatest advantage to Alpha Trailers. This decision was based largely on the available market gap for such a platform in South Africa, and due to its plausibility in terms of scope. During platform development it was considered that the concept of a logging trailer is largely based around the pre-existence of a general lifting trailer, and hence could be considered a derivative of such a platform. Since no such platform exists currently in Alpha Trailers’ range, it was decided that an initial platform of a ‘General Consumer’s Light Lifting Trailer’ be undertaken such that the logging derivative become a future endeavour. The promising opportunity of an Energy Recycling Trailer was developed into an add-on platform, which would form part of a range of additional attachments in Alpha Trailers portfolio. To avoid biasing the concept generation process with pre-conceived ideas, an initial platform development plan was constructed purely out of the functional requirements of the platform. This can be seen below in Figure 4:

Figure 4: Product function platform

Upon concept selection, the functions in the above diagram were replaced with their corresponding set of shared assets to form the final product platform plan in Figure 3. During benchmarking and specifications development it was decided that a logging trailer would not be categorised appropriately as a light trailer, and would rather constitute a medium to heavy trailer. It was decided that it would be warranted, given the potential market space, to pursue a heavy-duty lifting trailer platform at a future date. A Heavy Logging Trailer would be a derivative of such a platform. Despite the rejection of a crane operated winch system for a light trailer lifting solution, it was holistically judged by the development team that such a concept be appropriate for a heavy duty trailer. It is recommended that upon the start product development for this future platform, such a solution be considered and re-evaluated through formal processes.

3.3. Mission Statement

Product description

A light trailer that is capable of lifting, securing and transporting a payload.

Key business goals

Introduce product into market by the end of 2015

Release second line of product by 2017

Achieve a 30% market share of commercial trailers by 2020

Primary market

General consumer requiring the transport (removal) of light to medium payloads

Secondary market

Logging/Forestry market

Construction market

Agricultural market

Assumptions

Trailer has a double-axle mechanism

Standard parts (tyres, wheels, etc.) are outsourced

Stakeholders

User

Manufacturer/Workshop

Suppliers

Design team

Staff (procurement, sales, costing, admin, etc.)

Retailer

Customer and product services

4. Customer Needs The primary and secondary needs were identified and are listed below:

1.

The trailer is easy to attach to a vehicle

* The trailer is able to be attached to most common motor vehicles.

* The trailer has an attachment method that is simple to use.

** The trailer can be attached by one person.

2. The trailer is efficient ** The trailer provides good loading time.

* The trailer can be closed and fastened quickly.

3. The trailer keeps the payload in good condition while loading

*** The trailer can load goods without damaging them.

*** The trailer safely secures payloads during lifting.

4. The trailer keeps the payload in good condition during transport

*** The trailer safely secures payloads during transport.

** The trailer provides secure fastening points.

*! The trailer has effective shock absorbers.

5. The trailer is multi-purpose ** The trailer can be used in various

industries. ** The trailer is designed to be

transportable across various terrains. * The trailer can function in any

environment (rural or urban).

6. The trailer is lightweight. ** The trailer mass falls within legal

specifications

7. The trailer is easy to store. ** The trailer dimensions fall within

national standards.

8. The trailer is long-lasting. * The trailer resists corrosive damage.

9. The trailer is affordable.

10. The trailer has a resilient chassis

* The trailer resists impacts (dents) and scratches.

** The trailer resists significant deformations due to loading.

*** The trailer maintains structural integrity under extreme conditions.

11. The trailer parts are durable * The trailer has durable tyres. * The trailer lights are protected from

damage. The trailer lights are protected from

exposure from environment.

12. The trailer is aesthetically appealing

13. The trailer is safe *** The trailer falls within national safety

standards. * The trailer has smooth non-abrasive

edges. * The trailer is electrically safe.

14. The trailer is strong ** The trailer is strong under loading.

*** The trailer is strong under impact. ** The trailer is rigid.

15. The trailer is self-supporting ** The trailer can remain level when

detached from the vehicle.

5. Target Product Requirement Specification 5.1. Target Specifications

The primary needs for the trailer were investigated and from them a list of metrics was established. These were linked to the relevant needs and an importance value was assigned to each (1 = not very important, 5 = very important). The marginal and ideal values were determined by comparison of the specifications associated with three established trailer designs – these benchmarks can be seen in the Quality Function Deployment overleaf – and are tabulated below:

Table 1: Target specifications based on benchmarked metrics

Met

ric

#

Nee

d(s

) #

Metric Imp Units Marginal

Value Ideal Value

1 1 Tow bar sizes 4 mm 50 50

2 1, 6 Total mass of trailer 5 kg <1100 <850

3 2 Time taken per load cycle 4 s <15 <10

4 2 Time taken to open and close trailer 3 s <25 <20

5 3 Maximum mass of payload per load cycle

4 kg >350 >500

6 4 Maximum mass of total payload 5 kg >1250 >2000

7 4, 5 Payload area 4 m^2 8-12 10

8 4 Number of fastening points 2 # 6-12 10

9 4, 5 Dampening ratio of suspension 3 ratio <0.7 <0.6

10 5 Clearance from ground level 3 mm >500 >500

11 5, 11 Type of tyre and wheel 3 inches >13’’ >15’’

12 7 Overall dimensions of trailer 4 (m)^3 <7x2.5x1.5 6x2x1

13 8 Corrosion resistivity 2 V 0.77 <0.77

14 8 Warranty of trailer 4 years >2 3

15 9 Price of trailer 4 k ZAR <160 <150

16 10, 12 Hardness of trailer material 2 BHN >95 100

17 10 Yield strength of chassis 3 MPa >215 250

18 10, 14 Deflection at static loading 3 mm 5-8 <5

19 10, 14 Deflection at impact loading 3 mm >8 15

20 11 Light protection material 1 type > Plastic Shielded

21 12 Instils pride 3 YES YES

22 13 Minimum radius of fillets and rounds 1 mm 5 5

23 14 Ultimate tensile strength 3 MPa >400 450

24 15 Trailer support included 3 YES/NO YES YES

5.2. Quality Function Deployment

The Quality Function Deployment (QFD) shown alongside summarises the target specifications of a trailer design. The needs are described in terms of their relative importance and the relevant metrics associated with them. These metrics are described by their units, difficulty of implementation and relative importance. They need to be optimised, however, in order to do so, their inter-relations need to be considered. Therefore a matrix has been included at the top of the QFD to show the correlation of related metrics. These effects are either positive or negative. The benchmarked competitors have been rated according to both the needs and metrics. From the metric comparisons, the target specifications for the trailer design are established. This will provide the benchmark on which to base the final specifications of the trailer.

Target Specifications

Difficulty Rating (1-easy, 5-difficult)

Relative Importance

Units

Kesla 203T Log Loader

Avant Timber Trailer

Airbagged Trailer

Relative Importance Rating1 – Not important5 – Very Important

Benchmark Rating1 – Weak Relationship5 – Strong Relationship

Correlation Symbols+ positive - negative

Figure 5: House of Quality illustrating correlations between needs, metrics and benchmarks.

6. Solution Concepts 6.1. Functional Analysis

The overall function of the trailer is to convert various energy, material (payload) and signals into a secure, transportable device. The sub-functions of this basic, “black box” approach are decomposed in Figure 6 below. The decomposition allows the sub-functional relationships to be analysed and the basic flow of energy, material and signal to be clarified. In order to perform the primary function of the trailer (i.e. to lift, secure and transport the payload) the flows shown in the functional analysis need to be supported.

Figure 6: Function diagram of a trailer representing overall (top) and refined (bottom) functional decomposition

6.2. Concept Classification Tree

A concept classification tree of one of the primary functions of the trailer is shown below. The function selected was the hoisting of the payload. A number of possible mechanisms were explored and energy solutions to these mechanisms were produced. Where relevant, additional resources to fulfil a particular energy field were also discussed.

Figure 7: Concept classification tree for the lifting mechanisms and energy source possibilities

6.3. Concept Sketches

6.3.1. Concept A

6.3.2. Concept B

6.3.3. Concept C

6.3.4. Concept D

6.3.5. Concept BD

6.3.6. Concept AC

7. Concept Selection After concepts A, B, C and D were developed, a concept screening matrix was used to verify the most useful of the designs to the company portfolio. From the results of the screening matrix it became clear that Concepts B and D showed the greatest promise when examined analytically. However, it was holistically judged from the weaknesses of Concepts A and C that a combination of their more promising assets might yield a better solution. Hence concept AC was generated. Furthermore, it was observed that a potential weakness of the very promising Concept D was that it required a smooth ground surface with no obtrusions for it to lower completely. It was initially considered that the prime advantage of such a trailer would be that very heavy payloads could be rolled or wheeled onto the flat bed. If the flat bed is unable to rest smoothly on the ground this is not possible and hence the off-road capabilities of such a trailer are extremely limited. A combination Concept BD was derived, incorporating the lowering function of the Concept D and the ramp-and-winch capabilities of Concept B. It was observed in Table 2 below that such a trailer would improve functionality and marketability.

Table 2: Selection criteria and concept-scoring matrix

Concept

B D AC BD

Extendable Ramp and Winch

Variable Height Hybrid Hybrid

Selection criteria Weight Rating Weighted

score Rating

Weighted score

Rating Weighted

score Rating

Weighted score

Efficiency 8% 3 0.24 4 0.32 3 0.24 4 0.32

Ease of use 15% 4 0.60 4 0.60 3 0.45 5 0.75

Durability 10% 3 0.30 4 0.40 4 0.40 4 0.40

Manufacturability 20% 5 1.00 2 0.40 2 0.40 2 0.40

Protection of load 8% 2 0.16 3 0.24 4 0.32 3 0.24

Marketability 17% 2 0.34 4 0.68 4 0.68 4 0.68

Versatility 12% 3 0.36 4 0.48 4 0.48 5 0.60

Cost 10% 5 0.50 2 0.20 3 0.30 2 0.20

Total Score 3.50 3.32 3.27 3.59

Rank 2 3 4 1

Continue? DEVELOP NO NO YES

Upon completing the scoring process, it became clear that Concept BD offered the greatest opportunity for a Light Lifting Trailer. Due mainly to its simplicity, concept B should also be considered for further development at a later date. As mentioned in the Product Development Plan, Concept AC has been judged to have strong capabilities for a Heavy Lifting Trailer and will be considered for such a future platform.

Provide DC supply

Attach payload

Hoist payload

Secure payload

Adjust height of deck

Provide hydraulic lift

Accept user input

Control winch

Control deck

Provide shock absorption

Provide braking

Enclose clusters

Provide rigid support

Attach to vehicle

Provide light signals

Functional or physical

interactions

Flow of forces or energy

Flow of materials

Flow of signals or data

8. Product Architecture

Figure 8: Schematic of adjustable bed trailer with winch system

Provide DC supply

Attach payload

Hoist payload

Secure payload

Adjust height of deck

Provide hydraulic lift

Accept user input

Control winch

Control deck

Provide shock absorption

Provide braking

Enclose clusters

Provide rigid support

Attach to vehicle

Provide light signals

CONTROL HUB

TRAILER CHASSIS

HYDRAULIC LIFT SYSTEM

WINCH

WHEEL SUB-ASSEMBLY

POWER SUPPLY

Figure 9: Element clustering of schematic

8.1. Fundamental and Incidental Interactions

The fundamental interactions are stated explicitly in Figure 8 and Figure 9. However, the incidental interactions need to be considered too. These would include:

Vibrations being set up in the winch hoisting and the hydraulic lifting mechanisms.

Heat dissipation in the control hub.

Aperiodic vibrations in the suspension system.

Thermal distortion in the wheel sub-assembly.

Depletion of power supply from battery.

Figure 10: Geometric layout of trailer

9. Allocation of Clusters In accordance with the project charter, the simplest cluster was allocated to the chief designer. This was the trailer chassis cluster and is the integral component of the entire trailer. The other clusters are:

Wheel sub-assembly – this cluster involves the design and calculation of an adequate

suspension and braking system as well as an effective axle mechanism.

Winch and control hub – this cluster involves the calculations regarding the pulling

and loading of goods on the trailer; there is also design required to ensure an

operational control hub to operate both the winch and lifting mechanisms.

Hydraulic lift system – this cluster involves the necessary calculations to ensure

adequate height adjustment for a maximum load and ensure no damage or failure of

the components occur; this cluster is comprised of the fundamental function of the

trailer.

The clusters are allocated as follows:

Table 3: Cluster allocation amongst members

Team member Role Cluster

Shaun Kriek Chief designer Trailer chassis

Mulanga Masikhwa Sub-assembly designer Winch and control hub

Yasteel Ramsuran Sitaram Sub-assembly designer Hydraulic lift system

Charlie Turnley Sub-assembly designer Wheel sub-assembly

Buddy Rating Scores UNIVERSITY OF CAPE TOWN

DEPARTMENT OF MECHANICAL ENGINEERING

MEC4103F PRODUCT DESIGN 2015

GROUP WORK DECLARATION FOR ASSIGNMENT 1

This form has to be completed by each Chief Designer and added to their Design File as part of the submission for Assignment 1.

Surname First name Student number

KRIEK SHAUN KRKSHA006

Group number Project

2 Trailer

I herewith declare that co-operation of team members during the execution of Assignment 1 was as follows:

Team members (excluding Chief Designer)

Surname Initial(s)

Provide approximate contribution to Assignment 1 (25% implies a full contribution)

MASIKHWA M 20

RAMSURAN SITARAM Y 25

TURNLEY C 25

Signed: ________________________ Date: 3/13/2015

assignment 1.pdf

Documents

light trailer

leading trailer company

seta film trailer

electricitya film trailer

excess trailer energy

logginga dump trailer

electricitya hovertrailer

filming chase scenesa