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COMPOSITE MATERIAL USING CREO AND ANSYS SOFTWARE

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DESIGN AND ANALYSIS OF I.C. ENGINEPISTON AND PISTON-RING ON

COMPOSITE MATERIAL USING CREOAND ANSYS SOFTWARE

<i><b>Keywords - Stress distribution, Four stroke engine piston, Finite element analysis, Aluminium alloy and SiC, Naturalfrequency, Vibration mode, Computer aided design (CAD), Ceramic matrix composite (CMC) material, Ansys.</b></i>

Automobile components are in great demand these days because of increased use of automobiles. The increaseddemand is due to improved performance and reduced cost of these components. R&D and testing engineers shoulddevelop critical components in shortest possible time to minimize launch time for new products. This necessitatesunderstanding of new technologies and quick absorption in the development of new products. A piston is acomponent 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 thecrankshaft via a piston rod and/or connecting rod. As an important part in an engine, piston endures the cyclic gaspressure and the inertial forces at work, and this working condition may cause the fatigue damage of piston, such aspiston side wear, piston head/crown cracks and so on. The investigations indicate that the greatest stress appears onthe upper end of the piston and stress concentration is one of the mainly reason for fatigue failure. This paperdescribes the stress distribution on piston of internal combustion engine by using FEA. The FEA is performed byCAD and CAE software. The main objectives are to investigate and analyze the thermal stress and mechanical stressdistribution of piston at the real engine condition during combustion process. The paper describes the FEA techniqueto predict the higher stress and critical region on the component. With using CREO 2.0 software the structural modelof a piston will be developed. Using ANSYS V14.5 software, simulation and stress analysis is performed.

An optimized piston which is lighter and stronger is coated with zirconium for bio-fuel. In this paper[1], thecoated piston undergone a Von misses test by using ANSYS for load applied on the top. Analysis of the stressdistribution was done on various parts of the coated piston for finding the stresses due to the gas pressure and

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thermal variations. Vonmisses stress is increased by 16% and deflection is increased after optimization. But all theparameters 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 engineperformance. Analysis of the stress distribution in the various parts of the piston to know the stresses due to the gaspressure and thermal variations using with Ansys. With the definite-element analysis software, a three-dimensionaldefinite-element analysis [3] has been carried out to the gasoline engine piston. Considering the thermal boundarycondition, the stress and the deformation distribution conditions of the piston under the coupling effect of thethermal load and explosion pressure have been calculated, thus providing reference for design improvement. Resultsshow that, the main cause of the piston safety, the piston deformation and the great stress is the temperature, so itisfeasible to further decrease the piston temperature with structure optimization. This paper [4] involves simulation ofa 2-stroke 6S35ME marine diesel engine piston to determine its temperature field, thermal, mechanical and coupledthermal-mechanical stress. The distribution and magnitudes of the afore-mentioned strength parameters are useful indesign, failure analysis and optimization of the engine piston. The piston model was developed in solid-works andimported into ANSYS for preprocessing, loading and post processing. Material model chosen was 10-nodetetrahedral thermal solid 87. The simulation parameters used in this paper were piston material, combustionpressure, inertial effects and temperature. This work [5] describes the stress distribution of the piston by using finiteelement method (FEM). FEM is performed by using computer aided engineering (CAE) software. The mainobjective of this project is to investigate and analyze the stress distribution of piston at the actual engine conditionduring combustion process.. The report describes the mesh optimization by using FEM technique to predict thehigher stress and critical region on the component. The impact of crown thickness, thickness ofbarrel and piston topland height on stress distribution and total deformation is monitored during the study[6] of actual four stroke enginepiston. The entire optimization is carried out based on statistical analysisFEA analysis is carried out using ANSYSfor optimum geometry.This paper describes the stress distribution and thermal stresses of three different aluminumalloys piston by using finite element method (FEM). The parameters used for the simulation are operating gaspressure, temperature and material properties of piston. The specifications used for the study of these pistons belongto four stroke single cylinder engine of Bajaj Kawasaki motorcycle.

<small>Fig. 1 : Labeled Image of a Piston</small>

Following materials are used for I.C. Engines pistons: Cast iron, Cast Aluminium, cast steel and forgedaluminium. The material used for piston is mainly aluminium alloy. Aluminium pistons can be either cast of forged.In early years cast iron was almost universal material for pistons because it posses excellent wearing qualities,coefficient of expansion and genera suitability in manufacture. But due to reduction of weight in reciprocating parts,the use of aluminium for piston was essential. To obtain equal strength a greater thickness of metal is necessary. But

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some of the advantages of the light metal is lost. Aluminium is inferior to cast iron in strength and wearing qualities,and its greater coefficient of expansion necessities greater clearance in the cylinder to avoid the risk of seizure. Theheat conductivity of aluminium is about thrice that of cast iron this combined with the greater thickness necessaryfor strength, enables and aluminium alloy piston to run at much lower temperature than a cast iron as a resultcarbonized oil doesn’t form on the underside of the piston, and the crank case therefore keeps cleaner. This coolrunning property of aluminium is now recognized as being quite as valuable as its lightness. Indeed; piston aresometimes made thicker than necessary for strength in order to give improved cooling.

In this paper the stress distribution is evaluated on the four stroke engine piston by using FEA. The finiteelement analysis is performed by using FEA software. The couple field analysis is carried out to calculate stressesand deflection due to thermal loads and gas pressure. The materials used in this project are aluminium alloy and SiCreinforced ZrB2 composite material. In this project the natural frequency and Vibration mode of the piston were alsoobtained and its vibration characteristics are analyzed. With using computer aided design (CAD), UNI-GRAPHICSsoftware the structural model of a piston will be developed. Furthermore, the finite element analysis performed withusing software ANSYS.

The methodology used for doing the analysis is as follows:

loads and working pressure of 3.3Mpa to find the stress distribution due to thermal and structural loads forAluminum alloy material.

The piston is designed according to the procedure and specification which are given in machine design anddata hand books. The dimensions are calculated in terms of SI Units. The pressure applied on piston head,temperatures of various areas of the piston, heat flow, stresses, strains, length, diameter of piston and hole,thicknesses, etc., parameters are taken into consideration .

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B. <i>ASSUMPTIONS MADE</i>

It is very difficult to exactly model the piston, in which there are still researches are going on to find outtransient thermo elastic behavior of piston during combustion process. There is always a need of some assumptionsto model any complex geometry. These assumptions are made, keeping in mind the difficulties involved in thetheoretical calculation and the importance of the parameters that are taken and those which are ignored. In modelingwe always ignore the things that are of less importance and have little impact on the analysis. The assumptions arealways made depending upon the details and accuracy required in modeling.

1. The assumptions which are made while modeling the process are given 2. The piston material is considered as homogeneous and isotropic.

below:-3. Inertia and body force effects are negligible during the analysis.4. The piston is stress free before the application of analysis.

5. The analysis is based on pure thermal loading and thus only stress level due to the above said is done the analysisdoes not determine the life of the piston.

6. Only ambient air-cooling is taken into account and no forced Convection is taken.7. The thermal conductivity of the material used for the analysis is uniform throughout.

8. The specific heat of the material used is constant throughout and does not change with temperature.

The following are the sequence of steps in which the piston is modeled.

The materials chosen for this work are Aluminum alloy and Silicon carbide reinforced Zirconium diboridefor an internal combustion engine piston. The mechanical properties of alloy and Silicon carbide reinforcedZirconium diboride are listed in the following table 1

<small>Table 1 Material Properties</small>

<i>a. A. Applying Temperatures, Convections and Loads</i>

The piston is divided into the areas defined by a series of grooves for sealing rings. The boundary conditionsfor mechanical simulation were defined as the pressure acting on the entire piston head surface (maximum pressurein the engine cylinder). It is necessary to load certain data on material that refer to both its mechanical and thermal

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<b>properties to do the coupled Thermo-mechanical calculations .The temperature load is applied on different areas and</b>

pressure applied on piston head. The regions like piston head and piston ring regions are applied with large amountof heat (160°C-200°C). The convection values on the piston wall ranges from 232W/mK to 1570W/mK. Theworking pressure is 3.3Mpa.

Structural analysis is performed on the piston by applying temperature distribution from the thermal analysis asbody loads using Ansys. Also a pressure of 3.3Mpa on the piston head. As we are coupling thermal analysis withstructural analysis, this analysis is called couple field analysis.

The results obtained from applying aluminium material for piston are,

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<small>Fig 4: Directional Deformation of aluminium piston Fig 5 : Von – Misses strain of aluminium piston</small>The results obtained from applying Silicon carbide reinforced Zirconium diboride material for piston are,

<small>Fig 6 : Total Deformation of SiC reinforced ZrB2 piston Fig 7: Directional Deformation of SiC reinforced ZrB2 piston</small>

The Thermal results obtained from applying aluminium material for piston are,

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<small>Fig 12 : Total Heat flex of SiC reinforced ZrB2 pistonFig 13 : Directional Heat flex of SiC reinforced ZrB2 piston</small>COMPARISON OF RESULT ON STATIC ANALYSIS IN PISTON

The results obtained from applying aluminium & SiC reinforced ZrB2 material for piston ring are,

<b><small>( Y Axis )</small></b>

<b><small>( Y axis )</small></b>

<b><small>Von – Missesstrain</small></b>

<small>SiC reinforced</small>

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<small>Fig 16: Directional Deformation of aluminium piston RingFig 17: Directional Deformation of SiC reinforced ZrB2 piston Ring</small>

<small>Fig 18 : Von – Misses strain of aluminium piston Ring Fig 19 : Von – Misses strain of SiC reinforced ZrB2 piston Ring</small>

The Thermal results obtained from applying aluminium & SiC reinforced ZrB2 material for piston Ring are,

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<small>Fig 22 : Total Heat flex of aluminium piston RingFig 23 : Total Heat flex of SiC reinforced ZrB2 piston Ring</small>COMPARISON OF RESULT ON STATIC ANALYSIS IN PISTON RING

The results obtained from applying aluminium & SiC reinforced ZrB2 material for piston ring assembely are,

<b><small>Flex( Y Axis )</small></b>

SiCreinforcedZrB2

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<small>Fig 26 : Total Deformation of aluminium assembly Fig 27 : Total Deformation of SiC reinforced ZrB2 assembly</small>

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The Thermal results obtained from applying aluminium & SiC reinforced ZrB2 material for piston ring assemblyare,

COMPARISON OF RESULT ON STATIC ANALYSIS IN PISTON RING ASSEMBLY

<small>SiCreinforcedZrB2</small>

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By comparing the above results we can easily concluded that the piston which made of aluminium material hashigh deformation and high heat flex distribution ,when the same analysis is done with composite material it has lowdeformation and low heat flex distribution. The results of all the analysis with different materials are compared andtabulated in the above table. From the results it is observed that stresses are within permissible limits for all the

<b>materials and it is observed that the deflections are very less for SiC reinforced ZrB2 Composite materialcompared to Al-Alloy.</b>

Modal analysis was carried out on piston with 2 different materials (Al-alloy and SiC reinforced ZrB2 Compositematerial) to determine the first 10 natural frequencies and fundamental mode shape of the structure. This wouldenable us to understand the dynamic behavior of the structure. The more is the fundamental natural frequency themore will be the stiffness of the structure. The boundary conditions used for modal analysis is as below

<b>Results of Modal analysis of piston for Al-alloy & SiC reinforced ZrB2 material: The first 10 natural</b>

frequencies of piston with Al-alloy material and SiC reinforced ZrB2 and the corresponding mode numbers aretabulated in the below table

<b><small>Mode No</small></b>

<b><small>Frequency ( Hz )Piston with Al –alloy</small></b>

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From the above modal analysis results it is observed that the first 10 natural frequencies are more for the pistonwith SiC reinforced ZrB2 Composite material. This indicates that the piston with SiC reinforced ZrB2 Compositematerial has more stiffness and dynamic response.

In this paper finite element analysis for static and dynamic conditions of the engine piston with different materialswas performed. The main objective of this project was to study the response of aluminium alloy and SiC reinforcedZrB2 composite material for the applied temperatures and pressure. From the results it is concluded that the pistonwith SiC reinforced ZrB2 composite material is having less defections, while the piston with aluminium alloy andgrey cast iron is having more deflections for the applied temperatures and pressures. It is also observed that thestress for all the materials is within the allowable limits of the respective material. From the modal analysis, it isobserved that piston with aluminium alloy is having less geometric stiffness, while the piston with SiC reinforcedZrB2 composite material is having more geometric stiffness. So, it is concluded that the fuselage piston with SiCreinforced ZrB2 composite material is the best choice for the manufacturing of the piston. In this project forcomplex designs it is recommended the use of the stress analyses software because complex geometries may causelarger errors in the analytical procedure.

[1] LINEAR STATIC STRUCTURAL ANALYSIS OF OPTIMIZED PISTON FOR BIO-FUEL USING ANSYSInternational 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 inEngineering & 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 ENGINEPISTON Journal of Theoretical and Applied Information Technology 20th February 2013. Vol. 48 No.2© 2005 - 2013JATIT & LLS. By HONGYUAN ZHANG, ZHAOXUN LIN, DAWEI XU.

[4] Simulation of Thermal-Mechanical Strength for Marine Engine Piston Using FEA Journal of Engineering Research andApplications www.ijera.com ISSN : 2248-9622, Vol. 4, Issue 3( Version 1),by Elijah Musango Munyao, Jiang Guo He,Yang Zhiyuan, Zou Xiang Yi .

[5] Piston Strength Analysis Using FEM Swati S Chougule, Vinayak H Khatawat / International Journal of EngineeringResearch 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.

[6] Design a four-cylinder Internal Combustion Engine International Journal of Mechanical Engineering Research &Applications Vol. 1 Issue 5, October – 2013 .ISSN: 2347-1719 by Radoslav Plamenov Georgiev,Dr. Pedro VillanuevaRoldan Dk.

[7] Design, Analysis and Optimization of Three Aluminium Piston Alloys Using FEA Ajay Raj Singh et al Int. Journal ofEngineering Research and Applications www.ijera.com ISSN : 2248-9622, Vol. 4, Issue 1( Version 3, January 2014,pp.94-102 by Ajay Raj Singh, Dr. Pushpendra Kumar Sharma

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