CHAPTER-1

INTRODUCTION

A piston is a component of reciprocating engines, reciprocating pumps, gas

compressors and pneumatic cylinders, among other similar mechanisms. It is the moving

component that is contained by a cylinder and is made gas-tight by piston rings. In an

engine, its purpose is to transfer force from expanding gas in the cylinder to

the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed

and force is transferred from the crankshaft to the piston for the purpose of compressing or

ejecting the fluid in the cylinder. In some engines, the piston also acts as a valve by

covering and uncovering ports in the cylinder wall. The petrol enters inside the cylinder

and the piston moves upwards and the spark plug produces spark and the petrol is set on

fire and it produces an energy that pushes the piston downwards.

1.1 INTERNAL COMBUSTION ENGINES

An internal combustion engine is acted upon by the pressure of the expanding

combustion gases in the combustion chamber space at the top of the cylinder. This force

then acts downwards through the connecting rod and onto the crankshaft. The connecting

rod is attached to the piston by a swivelling gudgeon pin (US: wrist pin). This pin is

mounted within the piston: unlike the steam engine, there is no piston rod or crosshead

(except big two stroke engines) .

The pin itself is of hardened steel and is fixed in the piston, but free to move in the

connecting rod. A few designs use a 'fully floating' design that is loose in both components.

All pins must be prevented from moving sideways and the ends of the pin digging into the

cylinder wall.

Gas sealing is achieved by the use of piston rings. These are a number of narrow

iron rings, fitted loosely into grooves in the piston, just below the crown. The rings are

split at a point in the rim, allowing them to press against the cylinder with a light spring

pressure. Two types of ring are used: the upper rings have solid faces and provide gas

sealing; lower rings have narrow edges and a U-shaped profile, to act as oil scrapers.

Pistons are cast from aluminium alloys. For better strength and fatigue life, some

racing pistons may be forged instead. Early pistons were of cast iron, but there were

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obvious benefits for engine balancing if a lighter alloy could be used. To produce pistons

that could survive engine combustion temperatures, it was necessary to develop new alloys

such as Y alloy and Hiduminium, specifically for use as pistons.

A few early gas engines had double-acting cylinders, but otherwise effectively all

internal combustion engine pistons are single-acting. During World War II, the US

submarine Pompano was fitted with a prototype of the infamously

unreliable H.O.R. double-acting two-stroke diesel engine. Although compact, for use in a

cramped submarine, this design of engine was not repeated.

1.1.1 TRUNK PISTONS

Trunk pistons are long relative to their diameter. They act both as a piston and

cylindrical crosshead. As the connecting rod is angled for much of its rotation, there is also

a side force that reacts along the side of the piston against the cylinder wall. A longer

piston helps to support this.

Trunk pistons have been a common design of piston since the early days of the

reciprocating internal combustion engine. They were used for both petrol and diesel

engines, although high speed engines have now adopted the lighter weight slipper piston.

A characteristic of most trunk pistons, particularly for diesel engines, is that they

have a groove for an oil ring below the gudgeon pin, in addition to the rings between the

gudgeon pin and crown.

To make these more compact, they avoided the steam engine's usual piston rodwith

separate crosshead and were instead the first engine design to place the gudgeon pin

directly within the piston. Otherwise these trunk engine pistons bore little resemblance to

the trunk piston; they were extremely large diameter and double-acting. Their 'trunk' was a

narrow cylinder mounted in the centre of the piston.

1.1.2 CROSSHEAD PISTONS

Large slow-speed Diesel engines may require additional support for the side forces

on the piston. These engines typically use crosshead pistons. The main piston has a

largepiston rod extending downwards from the piston to what is effectively a second

smaller-diameter piston. The main piston is responsible for gas sealing and carries the

piston rings. The smaller piston is purely a mechanical guide. It runs within a small

cylinder as a trunk guide and also carries the gudgeon pin.

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1.1.3 SLIPPER PISTONS

A slipper piston is a piston for a petrol engine that has been reduced in size and

weight as much as possible. In the extreme case, they are reduced to the piston crown,

support for the piston rings, and just enough of the piston skirt remaining to leave two

lands so as to stop the piston rocking in the bore. The sides of the piston skirt around the

gudgeon pin are reduced away from the cylinder wall. The purpose is mostly to reduce the

reciprocating mass, thus making it easier to balance the engine and so permit high speeds.

A secondary benefit may be some reduction in friction with the cylinder wall, since the

area of the skirt, which slides up and down in the cylinder is reduced by half. However

most friction is due to the piston rings, which are the parts which actually fit the tightest in

the bore and the bearing surfaces of the wrist pin, the benefit is reduced.

1.2 CATIA

Catia (an acronym of computer aided three-dimensional interactive application) a

multi-platform computer-aided design(CAD)/computer manufacturing (CAM)/computer-

aided engineering (CAE) softwaresuite developed by the company Dassault Systems. It is

written in the C++.

Catia (computer aided three-dimensional interactive application) started as an in-

house development in 1977 by french aircraft manufacturer avions marcel dassault, at that

time customer of the cad/cam cad software[1] to develop dassault's mirage fighter jet. it was

later adopted in the aerospace, automotive, shipbuilding, and other industries.

1.2.1 HISTORY

Initially named cati (conception assistéetridimensionnelle interactive – french

for interactive aided three-dimensional design ), it was renamed catia in 1981 when

dassault created a subsidiary to develop and sell the software and signed a non-exclusive

distribution agreement with ibm.

In 1984, the Boeing Company chose CATIA V3 as its main 3D CAD tool,

becoming its largest customer.

In 1990, General Dynamics Electric Boat Corp chose CATIA as its main 3D CAD

tool to design the U.S. Navy's Virginia class submarine. Also, Lockheed was selling

its CADAM CAD system worldwide through the channel of IBM since 1978.

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In 1992, CADAM was purchased from IBM, and the next year CATIA CADAM

V4 was published.

In 1996, it was ported from one to four Unix operating systems, including

IBM AIX, Silicon Graphics IRIX, Sun Microsystems SunOS, and Hewlett-Packard HP-

UX.

In 1998, V5 was released and was an entirely rewritten version of CATIA with

support for UNIX, Windows NT and Windows XP (since 2001).

In the years prior to 2000, problems caused by incompatibility between versions of

CATIA (Version 4 and Version 5) led to $6.1B in additional costs due to years of project

delays in production of the Airbus A380.

In 2008, Dassault Systems released CATIA V6. While the server can run

on Microsoft Windows, Linux or AIX, client support for any operating system other than

Microsoft Windows was dropped.

In November 2010, Dassault Systems launched CATIA V6R2011x, the latest

release of its PLM2.0 platform, while continuing to support and improve its CATIA V5

software.

1.2.2 SCOPE OF APPLICATION

Commonly referred to as a 3D Product Lifecycle Management software suite,

CATIA supports multiple stages of product development (CAx), including

conceptualization, design (CAD), engineering (CAE) and manufacturing (CAM). CATIA

facilitates collaborative engineering across disciplines around its 3DEXPERIENCE

platform, including surfacing & shape design, electrical fluid & electronics systems

design, mechanical engineering and systems engineering.

CATIA facilitates the design of electronic, electrical, and distributed systems such

as fluid and HVAC systems, all the way to the production of documentation for

manufacturing.

1.2.3 APPLICATIONS

Goodyear uses it in making tires for automotive, ship building , industrial

equipment and aerospace and also uses a customized CATIA for its design and

development. Many automotive companies use CATIA for car structures – door beams, IP

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supports, bumper beams, roof rails, side rails, body components because of CATIA's

capabilities in Computer representation of surfaces. 

1.2.4 COMMANDS USED IN CATIA FOR MODELING

CATIA Version 5 Basic Concepts

The main objective of this lesson is to present the necessary tools and concepts for

the user to successfully navigate the CATIA V5 environment. Some things in this lesson

are covered in general terms while others are covered in detail. The user is expected to

learn and understand each item as presented in the lesson. Tools and concepts that are

briefly introduced in this lesson lay the foundation for gaining deeper knowledge in later

lessons. Another purpose of the general introduction is to present the user with enough

information to promote self-discovery of CATIA V5.

1.2.4.1 CATIA V5 STANDARD SCREEN LAYOUT

The following standard screen layout shows you where different tools and toolbars

are located. The numbers coordinate with the following pages where the tool label is

bolded. The tool label is followed by a brief and in some cases, steps on how to use and/or

access the tool shown in a below Figure 1.1.

Fig.1.1Catia standard screen layout

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1.2.4.2 THE START MENU

The Start pull down menu gives you access to all of the CATIA V5 Workbenches.

The availability of the workbenches will depend on the CATIA V5 licenses configuration,

the one shown in Figure 1.2.

The workbenches used in this workbook will be found under Mechanical Design,

Shape, and Digital Mockup Workbench Categories. If you select the arrow to the right of

the Workbench Category the workbenches organized within that category will be

displayed, shows the workbenches organized under the Mechanical Design Category, the

Part Design Workbench is the highlighted workbench.

Fig.1.2 Start menu

1.2.4.3SELECT THE PART DESIGN WORKBENCH ICON

The Welcome to CATIA V5 window displays. This icon is located in the toolbars

along the right side of the display, near the top. Notice that the three favorite workbenches

that were chosen display here as well. This provides another method for switching between

workbenches shown in a Fig 1.3.

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Fig.1.3 Workbench icon

1.2.4.4THE STANDARD WINDOWS TOOLBAR

The Standard Windows toolbar contains your standard MS Windows pull down

menus, reference Figure There are specific CATIA V5 tools found in the different pull

down menus. The tools you will be required to use in this workbook will be defined in the

lesson that they are used in. as shown in Fig 2.4

Fig.1.4 Tool bar

File Menu :The options under the File pull down menu are very similar to most other MS

Windows programs as shown in Fig 1.5.

Edit Menu :The first few options under the Edit pull down menu is very similar to most

other MS Windows programs. The first options are also available on the Standard, such as

the Undo [Ctrl+Z], Repeat [Ctrl+Y], Cut [Ctrl+X], Copy [Ctrl+C] and Paste [Ctrl+V]as

shown in Fig 1.6.

Delete [Del]: This is one of the numerous methods CATIA V5 allows for you to delete

selected items.

Update [Ctrl+U]: The Update tool allows you to force the document to be updated. There

is a toggle in Tools>Options that allows CATIA V5 to update automatically. When the

Update tool is dimmed there is no update to be performed.

Search [Crtl+F]: The Search tool allows you to search the document for almost any type

of variable. Selecting this tool brings up a Search window that allows you to input specific

parameters to help narrow the search.

Links: The Links tool allows you to view all documents that are linked to the current

document. This is a very useful tool when dealing with a multitude of linked documents

such as assemblies.7

Properties [Alt+Enter]: The Properties tool allows you to view and/or modify the

properties of the selected element. This tool is also available contextually (selecting the

element and then selecting the right mouse button).

Scan or Define In Work Object: This tool allows you to review how the part in the

document was created, step-by-step. This is a powerful design and review tool that is

covered in depth in the Part Design Lesson.

Fig.1.5 File menu Fig.1.6 Edit menu

View Menu

Most of the tools in this pull down menu have to functions dealing with the

visualization of the CATIA V5 document. Many of the tools can be accessed from the

bottom toolbar, quick keys and contextually (right mouse click). Figure 1.6 displays the

tools available in the View pull down menu. The following is a brief description of each

tool found in the View Pull Down Menu.

Toolbars: Toolbars allows you to toggle additional toolbars on and off. If a particular tool

gets closed you can use this tool to turn it back on. This is covered in more detail later in

this lesson.

Command List: This tool brings up the Command List window that lists all the CATIA

V5 commands. For example if you wanted to create a Point and could not find the Point

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tool, you could go to View > Command List and browse for the Point, select Point and

enter the appropriate values for X, Y and Z.

Geometry: This is a toggle tool that places the geometry into hide/show (visible/not

visible). CATIA V5 Workbook

Specification: This is a toggle tool that places the Specification Tree into hide/show.

Notice that there is also a quick key for this, F3.

Compass: This is a toggle tool that places the compass into hide/show.

Reset Compass: This tool allows you to reset the compass back to its original location and

orientation.

Tree Expansion: This tool allows you to expand the Specification Tree automatically, at

specified levels, or contract the Specification Tree.

Full Screen: This tool allows the workspace to take the entire area of the screen, all the

tools and toolbars disappear. This option provides significantly more work area for your

geometry. To bring back all the toolbars, make sure your cursor is over an open section of

the workspace and select the right mouse button.

1.2.4.5COMMANDS DESCRIPTION

Creating a positioned sketch Enables you define (and later change) explicitly the

position of the sketch absolute axis. this offers of the following advantages

you can use the absolute axis directions like external references for the sketched profile

geometry.

when the geometry of the parts evolves and the associated position of the sketch changes.

the shape of the sketched profile (2d geometry of the sketch ) remains unchanged (even if

the sketched profile is under constrained)

Select the sketcher icon and click the desired reference plane either in the geometry

area or in the specification tree, or select a planar surface. this creates a ''non positioned

''sketch . the sketch absolute axis may ''slide'' an the reference plane when the part is

updated.

.

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sketch one plane of the local axis. h and v are aligned to the main axis of this selected

plane. associatively is kept between both the plane and the sketch.

Exit is used to exit the sketcher workbench whenever you want.

Grid activated this option makes your sketch begin or end on the points of the grid .as

you are sketching the points are snapped the intersection points of the grid.

Sketched geometry

Profile how to create a closed profile .a profile may also be open (if you click the

profile end point in the free space). profiles may be composed of lines and arcs, which you

create either by clicking or using the Sketch tools toolbar.

Line (active by default) , tangent arc .

Rectangle shows how to create to create a rectangle in the direction of your choice by

defining three extremity points of the rectangle. In this task, we will use the Sketch tools

toolbar but of course you can create this oriented rectangle manually. For this, move the

cursor to activate Smart Pick and click as soon as you get what you wish.

oriented rectangle cylindrical elongated hole key hole

hexagon

Elongated Hole this all are included in same icon.

circle This task shows how to create a circle. In this task, we will use the Sketch tools

toolbar but of course you can create this circle manually. For this, move the cursor to

activate Smart pick and click as soon as you get what you wish. Some other commands in

circle below.

Operation on sketched geometry:

Corners This task shows how to create a rounded corner (arc tangent to two curves)

between two lines using trimming operation. You can create rounded corner between

curves.

You can create several corners just by multi - selecting for example, the rectangle

end points and enter a radius value in the Radius field (Sketch tools toolbar). Four corner

are created at the same time with the same radius value.

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options included in trim command:

no trim trim one trim both elem.

Chamfer (ctrl h)This task shows how to create a chamfer between two lines

trimming either all, the first or none of the elements, and more precisely using one of the

following chamfer definitions:

1.2.4.6 TRANSFORMATIONS

Symmetry shoes you how to repeat existing Sketcher elements using a line, a

construction line of an axis. In this particular case we will duplicate a circle.

translate Elements shoe you to perform a translation on 2D elements by defining the

duplicate mode and then selecting the element to be duplicated. Multi-selection is not

available The application provides a powerful command for translating elements. you

may either perform a simple translation (by moving elements) or create several copies of

2D elements. Translating element also means re-computing distance, angle and/or length

constraint values, of needed. Be careful: only non-foxed elements are updated.

Rotate Elements shoe you to rotate elements by defining the duplicate mode and

then selecting the element to be duplicated. In this scenario, the geometry is simply

moved. But note that, you can also duplicate elements with the Rotation command.

Rotating elements also means re-computing distance values into angle values, if needed.

Be careful: only non-fixed elements are updated.

Offset shows hoe to duplicate an element of the following type: line, arc of circle.

You can also duplicate by offset one of the following: an edge, a face (all the boundaries

of this face are offset) or a geometrical feature (for example, by selecting a join or another

sketch in the specification tree).

Offset options:

Offset 2D geometry,

Use offset tools,

Offset 3D geometry,

Modify a 3D geometry offset.

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Constraints (Dialog Box) (Crtl O) shows you how to set various geometrical

constraints using a dialog box. For example, you can use the Constraint command to

finalize your profile and set constraints consecutively. You may define several constraints

simultaneously using the Constrain Definition dialog box, or by means of the contextual

command (right-click).

Dimensional/Geometrical (Ctrl C) shows you how to set dimensional of geometrical

constraints between one, two of three elements. The constrains are in priority

dimensional. Use the contextual many to get other types of constraints and to position this

constraint a desired. In this particular case, we will set constrains between to elements by

selecting the command and then a line and a circle.

1.2.4.7 SKETCH- BASED FEATURES

Feature are entities you combine to make up your part. The features presented here

are obtained by applying commands on initial profiles created in the Sketcher workbench

(See CATIA-Dynamic sketcher User's Guide Version 5) pr in the Generative shape Design

workbench (See CATIA Generative shape Design User's Guide Vision 5) as well as

surfaces. Some operations consist in adding material, others in removing material. In

this section, you will learn how to create the following features:

Pad Creating a pad means extruding a profile of a surface in one or two directions.

The application lets you limits of creation as well as the direction of extrusion. This task

shoes you how to create a basic pad using a closed profile, the Dimension and Mirrored

extent options.Pad options:

Up to Next

Up to Plane

Up to Last

Up to Surface

HoleCreating a pocket consists in extruding a profile or a surface and removing the

material resulting from the extrusion. The application lets you choose the limits of

creation as well as the direction of extrusion. The limits you can are the same as those

available for creating pads. To know how to use them, up to Next Pads, Up to Last Pads,

Up to Plane pads, Up to Surface pads.12

Rib shows you how to create a rib that is how to sweep a profile along a center curve

to create material. To define a rib, you need a center curve, a planner profile and possibly

a reference element of a pulling direction

Stiffener shows you how to create a stiffener by specifying creation directions. Open

profile has been created in a plane normal to the face on which the stiffener will lie.

1.2.4.8 DRESS-UP FEATURES

Create an Edge Fillet: Click this icon, select the edge to be filleted, enter the radius

value and set the propagation mode in the dialog box.

Create a Variable Radius Fillet: Click this icon, select the edge to be filleted, enter

new radius values for both of the detected vertices, click as many points as you wish on

the edge and enter appropriate radius values for each of them. if needed, define a new

variation mode.

Create a chamfer: Click this icon, select the edge to be chamfered, set the creation

mode then define the parameters you have set.

Create a Basic Draft: Click this icon, set the Selection by neutral face selection

mode or select the face to be drafted, then enter the required parameters.

Create a Draft with a Parting Element: Click this icon, set the Selection by neutral

face selection mode or select the face to be drafted, expand the dialog box then enter the

required parameters.

1.2.4.9REFERENCE ELEMENTS

Create a Point: Click this icon, choose the reaction method then define the required

parameters.

Create a Line: Click this icon, choose the reaction method then define the required

parameters.

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Create a Plane: Click this icon, choose the reaction method then define the required

parameters.

1.2.4.10 TRANSFORMATION FEATURES

Create a Translation: Click this icon, select the body to be translated, define the

translation direction and enter the distance value.

Create a Rotation: Click thisicon, select the body to be rotated, define the rotation

axis and enter the angle value.

Create symmetry: Click this icon, select the body to be duplicated and define the

symmetry reference.

Create a Mirror: click this icon, select the body to be mirrored and define the

reference.

Create a Rectangular Pattern: Click this icon, select the feature to be duplicated,

define the creation directions, choose the parameters you wish to define and set these

parameters.

1.2.4.11 SURFACE-BASED FEATURES

Split means you can split a body with a plane, face or surface. The purpose of the

task is to show how to split a body by means of a surface.

Thick surface means you can add material to a surface in two opposite directions by

using the Thick Surface capacity. This task shows you how to do so.

1.2.4.12 VIEW TOOLBAR

Fly mode: Sets the fly mode. This is a very powerful and fun tool.

Fit All In: This tool will show the extent of all the graphics currently on the screen. It

is a quick way to see what elements are on the screen and where they are in relationship to

one another.

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Pan: This tool allows you to move the part around on the screen. The part does not

change its location in the XYZ coordinate system, only in relationship to the screen.

Rotate: This tool allows you to rotate the part in three dimensional space. It will

place a representation of a space ball (sphere) in the center of the screen. There is a three-

dimensional X on the space ball, you drag the X to where you want on the space ball and

the part will rotate accordingly. This tool is critical to part manipulation. It is important

that you get the hang of rotating the part to the orientation you want. This tool must be

selected every time you want to rotate the part.

Zoom In: This is similar to other graphics programs. This allows you to get a closer

look at finer detail. Press the middle mouse button, hold it down as you press the left

mouse button and release it. Now use the mouse to drag the cursor up the screen and the

part will Zoom In.

Zoom Out: This is similar to other graphics programs. This allows you to get the big

picture, making the part smaller. Press the middle mouse button, hold it down as you press

the left mouse button and release it. Now drag the mouse down the screen and the part will

Zoom Out.

Normal View: This tool allows you to view a particular plane/surface in a true length

view. You specify the plane/surface and CATIA V5 will rotate the plane/surface 90

degrees to your screen view.

Hide/Show: This tool allows you to select any entity or multiple entities and place

them in “no show space”. This removes the selected entity/entities from the “working

space”. Sometimes there are entities that you want to keep for future references but do not

want them visually

in the way.

. The Apply Material Tool : This tool allows you to apply a material to your solid.

Applying a material will give it the properties of the material such as the density so CATIA

V5 can calculate weight, volume and other part analysis information. Applying material

also gives the solid the texture and color of the selected material. CATIA V5 has a library

of material. The use of this tool is covered in the Part Design Lesson. Remember, to see the

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material applied to the solid you must select Apply Material in the Applies Customized

View Parameters.

1.3 ANSYS

ANSYS, Inc. is an American Computer-aided engineering software developer

headquartered south of Pittsburgh in Cecil Township, Pennsylvania, United States. Ansys

publishes engineering analysis software across a range of disciplines including finite

element analysis, structural analysis, computational fluid dynamics, explicit and implicit

methods, and heat transfer.

1.3.1 HISTORY

The company was founded in 1970. by John A. Swanson as Swanson Analysis

Systems, Inc (SASI). Its primary purpose was to develop and market finite element

analysis software for structural physics that could simulate static (stationary), dynamic

(moving) and thermal (heat transfer) problems. SASI developed its business in parallel

with the growth in computer technology and engineering needs. The company grew by 10

percent to 20 percent each year, and in 1994 it was sold to TA Associates. The new owners

took SASI’s leading software, called ANSYS, as their flagship product and designated

ANSYS, Inc. as the new company name.

Ansys has acquired a number of companies since 2000, including ICEM CFD

Engineering, Space-claim, CADOE S.A., of Lyon, France, a company specializing in

parametric analysis, and numerous French clients, including , Renault and Airbus, and

CFX (2003); Century Dynamics, Harvard Thermal, and Fluent Inc. (2006); Ansoft

Corporation (2008); Apache Design Solutions (2011); Esterel Technologies (2012); EVEN

and Reaction Design (2013);[13] and Spaceclaim Corporation (2014).

Ansys was listed on the NASDAQ stock exchange in 1996. In 2011, Investor's

Business Daily gave the firm a top score on its SmartSelect composite ratings.The

organization claims to reinvest 15 percent of its revenues each year into research to

continually refine the software.

1.3.2 ANSYS WORKBENCH

ANSYS can import CAD data and also enables to build geometry with its "pre-

processing" abilities. Similarly in the same pre-processor, finite element model (a.k.a.

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mesh) which is required for computation is generated. After defining loadings and carrying

out analyses, results can be viewed as numerical and graphical.

ANSYS can carry out advanced engineering analyses quickly, safely and

practically by its variety of contact algorithms, time based loading features and nonlinear

material models.

ANSYS Workbench is a platform which integrates simulation technologies and

parametric CAD systems with unique automation and performance. The power of ANSYS

Workbench comes from ANSYS solver algorithms with years of experience. Furthermore,

The object of ANSYS Workbench is verification and improving of the product in virtual

environment.ANSYS Workbench, which is written for high level compatibility with

especially PC, is more than an interface and anybody who has an ANSYS license can work

with ANSYS Workbench. As same as ANSYS interface, capacities of ANSYS Workbench

are limiteddue to possessed license. Structural Analysis.

1.3.3PARTS

ANSYS Autodyne ANSYS Autodyne is computer simulation tool for simulating the

response of materials to short duration severe loadings from impact, high pressure or

explosions.

ANSYS Mechanical ANSYS Mechanical is a finite element analysis tool for structural

analysis, including linear, nonlinear and dynamic studies. This computer simulation

product provides finite elements to model behaviour, and supports material models and

equation solvers for a wide range of mechanical design problems. ANSYS Mechanical

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also includes thermal analysis and coupled-physics capabilities involving acoustics,

piezoelectric, thermal structural and thermo-electric analysis.

Fluid Dynamics ANSYS Fluent, CFD, CFX, and related software are Computational

Fluid Dynamics software tools used by engineers for design and analysis. These tools

can simulate fluid flows in a virtual environment — for example, the fluid dynamics of

ship hulls; gas turbine engines (including the compressors, combustion chamber,

turbines and afterburners); aircraft aerodynamics; pumps, fans, HVAC systems, mixing

vessels, hydro cyclones, vacuum cleaners, etc.

1.3.4. ELECTRONICS

ANSYS HFSS ANSYS HFSS is a Finite Element Analysis tool for simulating full-

wave electromagnetic fields. HFSS incorporates finite element, integral equation, and

hybrid methods to solve a wide range of microwave, RF and high-speed digital

applications.

ANSYS Maxwell ANSYS Maxwell is a Finite Element Analysis tool for

electromagnetic field simulation, primarily for engineers tasked with designing and

analyzing electromagnetic and electromechanical devices, including motors, actuators,

transformers, sensors and coils. ANSYS Maxwell incorporates finite element method

solvers to solve static, frequency-domain, and time-varying electromagnetic and

electric fields.

ANSYS SI wave

ANSYS SIwave is a specialized design platform for power integrity, signal

integrity and Electromagnetic interference (EMI) analysis of electronic packages and

PCBs.

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CHAPTER-2

STATIC STRUCTURAL

The Structural template defines a basic structural simulation process that can be

used to simulate and evaluate the displacements, stresses, strains, and forces in structures

or components caused by loads that do not induce significant inertia and damping effects.

2.1 EXPORTING MATERIALS

Material Assignment 

You can export a material for use in another project. Exporting materials is only supported

for files. Follow the procedure below:

1. In the Material Assignment panel, click the link to the material.

2. Click the library show the source information of the material which includes the

library name, material name, and library location.

3. Click Export this material to a library.

4. Aside from exporting the material to an already loaded library, you have two

options:

2.2 GEOMETRY

A simulation process typically requires a geometry that represents a physical object

that you want to apply to your engineering simulation. ANSYS AIM enables you to import

various geometric and CAD file types. The geometry you provide will be used as the basis

for the subsequent assignment of mesh generation, physics, and results properties and

tasks.

You can import one or more geometry files into your study, or configure various

aspects of the simulation ahead of time

For instance, you can import a single geometry that represents both a fluid and

structural region, or you can import more than one geometry file: one that represents a

fluid flow region, and the other that represents a structural region.

19

2.3 MESHING

ANSYS AIM provides meshing capabilities for various geometric models.

when the imported geometry represents a structural region (or solid part), or when the

imported geometry represents a fluid region (or fluid flow volume), use part-based

meshing to create a mesh. you can also use part-based meshing to create separate meshes

for fluid regions and structural regions when you import multiple geometry files.

when the imported geometry represents solid parts and a flow volume needs to

be extracted, use a volume creation task, along with flow volume meshing, to create a

mesh. in this case, meshing the flow volume involves identifying the location of the flow

volume, generating a surface wrap mesh for the extracted volume, and then meshing the

volume itself. when the imported geometry represents multiple solid parts that you want to

unite to create a single flow region, or if you want to simplify a body with many surface

patches, use a volume creation task to simplify the geometry and generate the surface

mesh, and then use flow volume meshing to create the volume mesh.

2.4 BOUNDARY CONDITIONS

Depending on the type of physics involved (fluid flow, structural, steady-state

thermal),or electric conduction, ANSYS AIM provides several means to control the

solution of the physics simulation.

ANSYS AIM allows you to specify physical conditions at the boundaries of your model

and apply them to your simulation.

2.5 STRUCTURAL BOUNDARY CONDITIONS

Boundary conditions for structural physics include:

Externally applied forces, pressures, and moments

Supports

Steady-state inertial forces

Zero and nonzero displacements

Temperature Conditions (for thermal strain)

20

2.6 STATIC STRUCTURAL SOLVER OPTIONS

Solver Options

When you create your physics solution using a template, a number of solver options are set

up using standard defaults. You can modify the default values for a given physics solution

on the Solver Settings and Output Controls panels.

Solver Settings

On the Solver Settings panel, the settings available define the solver and the options

available to allow you to run a physics solution. Launch controls control how the solver is

launched and how the solver data is managed. Properties include solver file locations, file

names, and distributed solve controls.

Output Controls

In the Output Controls panel, you can control how the solution data is written to the

output file by defining one or more output specifications, which set the solution location,

output type, and frequency. These output specifications are processed sequentially based

on the order they are listed in the Output Controls panel.

By default, three output specifications are created for a static structural physics solution:

Nodal DOF Solution

Nodal Reaction Loads

Element Nodal Stresses

If you want to add Strain or other output types to the result file, you can create additional

Output Controls objects for the same location.

21

CHAPTER-3

LITERATURE REVIEW

An optimized piston which is lighter and stronger is coated with zirconium for bio-

fuel. In this paper[1], the coated piston undergone a Von misses test by using ANSYS for

load applied on the top. Analysis of the stress distribution was done on various parts of the

coated piston for finding the stresses due to the gas pressure and thermal variations.

Vonmisses stress is increased by 16% and deflection is increased after optimization. But all

the parameters are well with in design consideration

Design, Analysis and optimization of piston [2] which is stronger, lighter with

minimum cost and with less time. Since the design and weight of the piston influence the

engine performance. Analysis of the stress distribution in the various parts of the piston to

know the stresses due to the gas pressure and thermal variations using with Ansys

With the definite-element analysis software, a three-dimensional definite-element

analysis [3] has been carried out to the gasoline engine piston. Considering the thermal

boundary condition, the stress and the deformation distribution conditions of the piston

under the coupling effect of the thermal load and explosion pressure have been calculated,

thus providing reference for design improvement. Results show that, the main cause of the

piston safety, the piston deformation and the great stress is the temperature, so it is feasible

to further decrease the piston temperature with structure optimization.

This paper [4] involves simulation of a 2-stroke 6S35ME marine diesel engine

piston to determine its temperature field, thermal, mechanical and coupled thermal-

mechanical stress. The distribution and magnitudes of the afore-mentioned strength

parameters are useful in design, failure analysis and optimization of the engine piston.

After studied the literature we are improving the Analysis results in the form of

mesh generation and design concepts.

22

CHAPTER-4

COMPONENT DESCRIPTION

A piston is a component of reciprocating IC-engines. It is the moving component

that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its

purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a

piston rod and/or connecting rod. As an important part in an engine, piston endures the

cyclic gas pressure and the inertial forces at work, and this working condition may cause

the fatigue damage of piston, such as piston side wear, piston head/crown cracks and so on.

Piston features include the piston head, piston pin bore, piston pin, skirt, ring grooves, ring

lands, and piston rings. The piston head is the top surface (closest to the cylinder head) of

the piston which is subjected to tremendous forces and heat during normal engine

operation.The investigations indicate that the greatest stress appears on the upper end of

the piston and stress concentration is one of the mainly reason for fatigue failure

In designing a piston for an engine, the following points should be taken into

consideration:

It should have enormous strength to withstand the high pressure.

It should have minimum weight to withstand the inertia forces.

It should form effective oil sealing in the cylinder.

It should provide sufficient bearing area to prevent undue wear.

It should have high speed reciprocation without noise.

It should be of sufficient rigid construction to withstand mechanical distortions.

It should have sufficient support for the piston pin.

In engine, transfer of heat takes place due to difference in temperature and from

higher temperature to lower temperature. Thus, there is heat transfer to the gases during

intakes stroke and the first part of the compression stroke, but the during combustion and

expansion processes the heat transfer take place from the gases to the walls. So the piston

crown, piston ring and the piston skirt should have enough stiffness which can endure the

pressure and the friction between contacting surfaces. In addition, as an important part in

engine, the working condition of piston is directly related to the reliability and durability of

engine.

23

4.1MATERIALS

The piston acts as a movable end of the combustion chamber. The stationary end of

the combustion chamber is the cylinder head. Pistons are commonly made of a cast

aluminium alloy for excellent and lightweight thermal conductivity. Thermal conductivity

is the ability of a material to conduct and transfer heat.

Commonly used materials for IC engine pistons are cast iron, cast steel, forged

steel, cast aluminium alloys and forged aluminium alloy.

4.2ENGINE SPECIFICATIONS

Table.4.1: Engine specification

PARAMETERS VALUES

Engine Type Four stroke, Petrol engine

Induction Air cooled type

Number of cylinders Single cylinder

Bore 51 mm

Stroke 48.8 mm

Length of connecting rod 97.6 mm

Displacement volume 99.27 cm3

Compression ratio 8.4

Maximum power 6.03 KW at 7500 rpm

Maximum Torque 8.05 Nm at 5500 rpm

Number of revolutions/cycle 2

4.3 CHARACTERISATION OF MATERIALS

The materials chosen for this work are A2618, A4032 and for an internal

combustion engine piston. The relevant mechanical and thermal properties of A2618,

A4032 and aluminium alloys are listed in the following table 4.1, 4.2.

The relevant mechanical and thermal properties of A2618, A4032

24

S

NPARAMETERS A2618

A4032

1 Elastic Modulus (GPa)73.7 79

2 Ultimate Tensile Strength (MPa) 480 380

3 0.2% Yield Strength (MPa 420 315

4 Poisson’s Ratio 0.33 0.33

5Thermal Conductivity (W/m/oC)

147 154

6Coefficient of Thermal Expansion (1/K) 25.9 x 10-6 79.2 x 10-6

7 Density (Kg/m3)2767.9 9 2684.9 5

Table.4.2 :Characterisation of materials

4.4METHODOLOGIES

Analytical design of pistons using specifications of Bajaj Kawasaki petrol engine.

Creation of 3D models of piston using ANSYS.

Meshing of 3D models using ANSYS.

Analysis of pistons using static stress analysis method.

Comparative performance of three aluminium alloy pistons under static stress

analysis method.

Analysis of pistons under thermal and mechanical loads i.e. the pistons are

subjected to a uniform gas pressure and non-uniform temperature distribution.

25

Comparative performance of the three aluminum alloy pistons under thermal and

mechanical loads i.e. the pistons are subjected to a uniform gas pressure and non-

uniform temperature distribution.

Select the best suited aluminum alloy.

Analyze the optimized model under static stress.

Analyze the optimized model under thermal and mechanical loads

4.5 ANALYTICAL DESIGN

IP = Indicated power produced inside the cylinder (W)

η = Mechanical efficiency = 0.8

n = Number of working stroke per minute = N/2 (for four stroke engine)

N = Engine speed (rpm)

L = Length of stroke (mm)

A = Cross-section area of cylinder (mm2)

Lc=Length of connecting rod (mm)

r = Crank radius (mm)

a = Acceleration of the reciprocating part (m/s2)

mp = Mass of the piston (Kg)

V = Volume of the piston (mm3)

Th=Thicknessofpistonhead(mm)

D = Cylinder bore (mm)

pmax= Maximum gas pressure or explosion pressure (MPa)

σt= Allowable tensile strength (MPa)

σut =Ultimate tensile strength (MPa)

F.O.S = Factor of Safety = 2.25

K = Thermal conductivity (W/m K)

T= Temperature at the centre of the piston head (K)

Te = Temperature at the edge of the piston head (K)

26

HCV = Higher Calorific Value of fuel (KJ/Kg) = 47000 KJ/Kg

BP = Brake power of the engine per cylinder (KW)

m = Mass of fuel used per brake power per second (Kg/KW s)

C = Ratio of heat absorbed by the piston to the total heat developed in the cylinder = 5%

b = Radial width of ring (mm)

Pw = Allowable radial pressure on cylinder wall (N/mm2) = 0.025 MPa

σp = Permissible tensile strength for ring material (N/mm2) = 1110 N/mm2

h = Axial thickness of piston ring (mm)

h1= Width of top lands (mm)

h2= Width of ring lands (mm)

t1 = Thickness of piston barrel at the top end (mm)

t2 = Thickness of piston barrel at the open end (mm)

ls = Length of skirt (mm)

µ = Coefficient of friction (0.01)

l1 = Length of piston pin in the bush of the small end of the connecting rod (mm)

do = Outer diameter of piston pin (mm)

Model calculations:

η = Brake power (B.P)/ Indicating power (I.P)

Therefore, I.P = B . P

η = 6.2/0.8 = 7.75 KW

Also, I.P = P x A x L x N /2

I.P = P x (π4 )d2 x L x (

N2 )

Substituting the values from Table

Mechanical efficiency of the engine (η) = 80 %

7.75 x 1000 = P x π4

×(0.051)2 x (0.0488) x 5000

(2×60)27

So, P = 18.66 x 105 N/m2 or P = 1.866 MPa

Maximum Pressure pmax = 10 x P

= 10 x 1.866 = 18.66 MPa

Analytical design for A2618 alloy piston

Analytical design for A2618 alloy piston is as follows:

Thickness of the Piston Head

According to Grashoff’s formula the thickness of the piston head is given by

th = D√ 3 pmax16 σt

where

σt= σ ut2.25 = 213.33 MPa

Therefore th = 51 x √ (3 x18.66)

(16 x213.33)

= 6.53 mm

Empirical formula:

th = 0.032 D + 1.5 = 3.2 mm

On the basis of the heat dissipation, the thickness of the piston head is given by:

th =C x HCV x m x BP ¿ x106 ¿¿¿

= [0.05 x 47000 x 34.45 x 10−3 x6.2] x 106

(12.56 x147 x20 x3600)

= 3.775 mm

The maximum thickness from the above formula is th is 6.53 mm.

Piston Rings

The radial width of the ring is given by:

b = D √3 p wσ p = 51 √

3 x 0.025110

28

= 1.33 mm

Axial thickness of the piston ring is given by:

h = (0.7b to b) = 0.7 x 1.33 = 0.932 mm ≈ 1 mm

Width of Top Land and Ring Lands

Width of top land:

h1 = (th to 1.2 th) = 6.53 mm

Width of ring land:

h2 = (0.75h to h) = 0.75 mm

Piston Barrel

Thickness of piston barrel at the top end:

t1 = 0.03 D + b + 4.9

= 0.03 x 51 + 1.33 + 4.9 = 7.76 mm

Thickness of piston barrel at the open end:

t2 = (0.25 t1 to 0.35 t1)

= o.25 x 7.76 = 1.94 mm ≈ 2 mm

Length of the skirt

Ls = (0.6 D to 0.8 D)

= 0.6 x 51 = 30.6 mm

Length of piston pin in the connecting rod bushing

L1 = 45% of the piston diameter

= 0.45 x 51 = 22.95 mm

Piston pin diameter do = (0.28 D to 0.38 D)

29

= 0.28 x 51 = 14.28 mm

The centre of the piston pin should be 0.02 D to 0.04D above the centre of the skirt.

Similarly, analytical design of A4032is carried out and the results are summarized as

follows

Analytical design for A4032 alloy piston

Thickness of the Piston Head: th = 7.3 mm.

Piston Rings: b = 1.33 mm and h = 1 mm.

Width of Top Land: h1 = 7.3 mm

Ring Lands: h2 = 0.75 mm

Thickness of piston barrel at the Top end: t1 = 7.76 mm

Open end: t2 = 2 mm Length of the skirt: ls = 30.6 mm

Length of piston pin in the connecting rod bushing:

l1 = 22.95 mm

Piston pin diameter: do = 14.2

30

CHAPTER-5

PROCEDURE FOR MODELING OF PISTON

5.1 PROCEDURE

Start → mechanical design → part design to activate the part design workbench

Fig.5.1 procedure

Click on the sketcher → select the XY plane

Fig.5.2 plane

Select the profile → portray the profile of the main body

31

Fig.5.3 2D piston profile

Select the shaft command → click on ok→ select the axis→ click on enter

Now we can generate the 3d model of piston with help of shaft command

Fig.5.4 3D piston model

32

Select the plane → click ok → select circle → draw a circle → select pocket

command up to surface → ok

Fig.5.5 3D Modeling of piston

The require model is to be designed with help of catia v5 software .

33

CHAPTER-6

SIMULATION PROCEDURE

6.1 ANSYS WORKBENCH

Click on ansyswork bench →double click on static structural

Fig.6.1: Ansys work bench

double click on engineering data→adding the new materials with help of property of

material

Fig.6.2:Material insert

34

click on geometry→ import geometry→ select the project piston

Fig.6.3: Import geometry

6.2 MESHING OF 3D MODEL OF PISTON

Click on mesh→ select default mesh→ right click solve

Fig.6.4:Mesh model

35

Static structural→insertapplying boundary conditions

Fig.6.5:Boundary condition

solution→ right click insert → deformation → total.

Fig.6.6:Total Deformation

36

6.3 DEFORMATION

Fig.6.7:Deformation

6.4 VON-MISES STRESS

Fig.6.8:Von-miss stress

37

6.5 FACTOR OF SAFETY

Fig.6.9: Factor of safety

6.6 STUDY STATE THERMAL

Click on ansys work bench →double click on study state thermal

Fig.6.10:Import geometry

38

Double click on engineering data →add new material with help of properties of material

Fig.6.11:Material Insert

Click on geometry→ import geometry→ select the project piston

Fig.6.12:Import geometry

39

6.7 MESHING OF 3D MODEL OF PISTON

Click on mesh→ select default mesh→ right click solve

Fig.6.13:Meshing

Static structural→ insert applying boundary conditions

Fig.6.14:Boundary condition

40

Solution→ right click insert → thermal→ select temperature

Fig.6.15:Boundary condition

6.8 TEMPERATURE DISTRIBUTION

Fig.6.16:Temperature distribution41

6.9 TOTAL HEAT FLUX

Fig .6.17:Total heat flux

6.10 GRAPHS

6.10.1Pressure vs deformation

Graph.6.1: pressure vs deformation

The graphs draw between the pressure vsdeformation as shown figure 6.18. Load

increases, deformation changes linearly.

42

6.10.2 pressurevs equivalents von-mises stress

Graph.6.2:pressure vs equivalent (von-mises) stress

43

CHAPTER-7

RESULTS

Thus the design, analysis and optimization of piston is successfully completed with

help of ‘CATIAV5’ and ‘ANSYS14’

This chapter describes the results of the experiment s, which were conducted on a

piston and in a modelling on a personal computer. We are conducting the project to

calculate the deformation , temperature distribution and von-mises stress. In this reaserch

we have to compare the two materials and to find the which one is better suitable .we are

mainly considers the parameters like mass, deformation, heatflux factor of safety.

Table.7.1: Comparing results

S.NO MATERIALS HEAT

FLUX

(W/mm2)

Factor of

safety

Deformation

(mm)

Mass(Kg)

1 Aluminium

A 4032

4.89713 2.02 0.12911 0.12691

2 Aluminium

A 2618

4.57845 2.56 0.13839 0.13084

44

CHAPTER-8

CONCLUSION

It is concluded from the results that the weight and volume of Aluminium A4032

is least among the another materials. Hence the forces are less, which enhances the

performance of the engine. The FOS Aluminium A4032 of 2.02 is , much higher than the

other materials, so further development of high power engine using this material is

possible. Further research may be done to select a material with less weight and higher

strength, so as to reduce the forces.

The first main conclusion that could be drawn from this work is that although

thermal stress is not the responsible for biggest slice of damaged pistons, it remains a

problem on engine pistons and its solution remains a goal for piston manufacturers. From

the analysis, it is evident that thermal stress was higher than mechanically induced stress

hence it could be concluded that the piston would fail due to the thermal load rather than

the mechanical load and hence during optimization design, this could be put into

consideration to ensure that thermal load is reduced.

It can also be deduced that individually, thermal and mechanical stress proportions

have a direct influence on the coupled thermal-mechanical stress hence during design each

load can be considered and reduced independently. It can be concluded that the piston can

safely withstand the induced stresses during its operation. The stress obtained by

theoretical calculation and FEA found to be approximately same.

And it will last a problem for long because efforts on fuel consumption reduction

and power increase will push to the limit weight reduction, that means thinner walls and

higher stresses. To satisfy all the requirements with regard to successful application of

pistons, in particular mechanical and high temperature mechanical fatigue and

thermal/thermal–mechanical fatigue there are several concepts available that can be used to

improve its use, such as design, materials, processing technologies, etc.

45

CHAPTER-9

REFERENCES

[1] LINEAR STATIC STRUCTURAL ANALYSIS OF OPTIMIZED PISTON FOR BIO-

FUEL USING ANSYS International Journal of Mechanical and Production

Engineering Research and Development (IJMPERD) ISSN 2249-6890 Vol. 3, Issue 2,

Jun 2013, 11-20 © TJPRC Pvt. Ltd. By CH. VENKATA RAJAM, P. V. K. MURTHY

, M. V. S. MURALI KRISHNA.

[2] Design Analysis and Optimization of Piston using CATIA and ANSYS International

Journal of Innovative Research in Engineering & Science ISSN 2319-5665(January

2013, issue 2 volume 1)by CH. VENKATA RAJAM, P. V. K. MURTHY, M. V. S.

MURALI KRISHNA, G. M. PRASADA RAO.

[3] AN ANALYSIS TO THERMAL LOAD AND MECHANICAL LOAD COUPLING

OF A GASOLINE ENGINE PISTON Journal of Theoretical and Applied Information

Technology 20th February 2013. Vol. 48 No.2© 2005 - 2013 JATIT & LLS. By

HONGYUAN ZHANG, ZHAOXUN LIN, DAWEI XU.

[4] Simulation of Thermal-Mechanical Strength for Marine Engine Piston Using FEA

Journal of Engineering Research and Applications www.ijera.com ISSN : 2248-9622,

Vol. 4, Issue 3(Version 1),by Elijah MusangoMunyao, Jiang Guo He, Yang Zhiyuan,

Zou Xiang Yi .

[5] Piston Strength Analysis Using FEM Swati S Chougule, Vinayak H Khatawat /

International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-

9622 www.ijera.com Vol. 3, Issue 2, March -April 2013, pp.1724-1731 by Swati S

Chougule, Vinayak H Khatawate.

46