Done design and analysis of i c engine

In order to analyze the phenomenon of bolt preload when piston of low speed diesel engine is assembled and maximum explosion pressure and temperature during piston working impact on piston’s strength and fatigue life, Coupled analysis of mechanical stress and thermal stress on the piston of 5S60 low-speed diesel engine have been done, and the fatigue life of the piston on the alternating load condition was calculated. Firstly, the FEM-model which consists of 10-node tetrahedral meshes was built for the piston by using Hypermesh software with arranging different density of element quality which was guaranteed with the mesh parameters. Secondly, after setting the boundary conditions, the thermal stress, the mechanical stress and the coupling stress of the piston were calculated by using Abaqus software. Finally, the fatigue life of the piston on the alternating load condition was calculated by using nSoft software. The results indicate that the fatigue damage is easily occurred on the side of the surrounding area of the threaded holes, and that position should be made an especially consideration for design.

COMPOSITE MATERIAL USING CREO AND ANSYS SOFTWARE

Article · July 2016

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Sathishkumar Kuppuraj

Sri Krishna College of Engineering and Technology

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DESIGN AND ANALYSIS OF I.C ENGINE

PISTON AND PISTON-RING ON

COMPOSITE MATERIAL USING CREO

AND ANSYS SOFTWARE

K Sathish Kumar

UG Student, Department of Mechanical Engineering, United Institute of Technology,

Coimbatore – 641020

Email: sathishkuppuraj@gmail.com

Abstract - In this Paper the stress distribution is evaluated on the four stroke engine piston by using FEA The finite element analysis is performed by using FEA software The couple field analysis is carried out to calculate stresses and deflection due

to thermal loads and gas pressure These stresses will be calculated for two different materials The results are compared for all the two materials and the best one is proposed The materials used in this project are aluminium alloy, and SiC reinforced ZrB2 composite material In this project the natural frequency and Vibration mode of the piston and rings were also obtained and its vibration characteristics are analyzed With using computer aided design (CAD), CREO software the structural model

of a piston will be developed Furthermore, the finite element analysis performed with using software ANSYS SiC reinforced ZrB2 : Silicon carbide reinforced Zirconium diboride is a ceramic matrix composite (CMC) material is also used.

Keywords - Stress distribution, Four stroke engine piston, Finite element analysis, Aluminium alloy and SiC, Natural frequency, Vibration mode, Computer aided design (CAD), Ceramic matrix composite (CMC) material, Ansys.

Automobile components are in great demand these days because of increased use of automobiles The increased demand is due to improved performance and reduced cost of these components R&D and testing engineers should develop critical components in shortest possible time to minimize launch time for new products This necessitates understanding of new technologies and quick absorption in the development of new products 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 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 This paper describes the stress distribution on piston of internal combustion engine by using FEA The FEA is performed by CAD and CAE software The main objectives are to investigate and analyze the thermal stress and mechanical stress distribution of piston at the real engine condition during combustion process The paper describes the FEA technique

to predict the higher stress and critical region on the component With using CREO 2.0 software the structural model

of 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], 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 itis 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 The piston model was developed in solid-works and imported into ANSYS for preprocessing, loading and post processing Material model chosen was 10-node tetrahedral thermal solid 87 The simulation parameters used in this paper were piston material, combustion pressure, inertial effects and temperature This work [5] describes the stress distribution of the piston by using finite element method (FEM) FEM is performed by using computer aided engineering (CAE) software The main objective of this project is to investigate and analyze the stress distribution of piston at the actual engine condition during combustion process The report describes the mesh optimization by using FEM technique to predict the higher stress and critical region on the component The impact of crown thickness, thickness ofbarrel and piston top land height on stress distribution and total deformation is monitored during the study[6] of actual four stroke engine piston The entire optimization is carried out based on statistical analysisFEA analysis is carried out using ANSYS for optimum geometry.This paper describes the stress distribution and thermal stresses of three different aluminum alloys piston by using finite element method (FEM) The parameters used for the simulation are operating gas pressure, temperature and material properties of piston The specifications used for the study of these pistons belong

to four stroke single cylinder engine of Bajaj Kawasaki motorcycle

Fig 1 : Labeled Image of a Piston

Following materials are used for I.C Engines pistons: Cast iron, Cast Aluminium, cast steel and forged aluminium 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

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 The heat conductivity of aluminium is about thrice that of cast iron this combined with the greater thickness necessary for strength, enables and aluminium alloy piston to run at much lower temperature than a cast iron as a result carbonized oil doesn’t form on the underside of the piston, and the crank case therefore keeps cleaner This cool running property of aluminium is now recognized as being quite as valuable as its lightness Indeed; piston are sometimes 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 finite element analysis is performed by using FEA software The couple field analysis is carried out to calculate stresses and deflection due to thermal loads and gas pressure The materials used in this project are aluminium alloy and SiC reinforced ZrB2 composite material In this project the natural frequency and Vibration mode of the piston were also obtained and its vibration characteristics are analyzed With using computer aided design (CAD), UNI-GRAPHICS software the structural model of a piston will be developed Furthermore, the finite element analysis performed with using software ANSYS

The methodology used for doing the analysis is as follows:

material

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

The piston is designed according to the procedure and specification which are given in machine design and data 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

B ASSUMPTIONS MADE

It is very difficult to exactly model the piston, in which there are still researches are going on to find out transient thermo elastic behavior of piston during combustion process There is always a need of some assumptions

to model any complex geometry These assumptions are made, keeping in mind the difficulties involved in the theoretical calculation and the importance of the parameters that are taken and those which are ignored In modeling

we always ignore the things that are of less importance and have little impact on the analysis The assumptions are always made depending upon the details and accuracy required in modeling

1 The assumptions which are made while modeling the process are given

below:-2 The piston material is considered as homogeneous and isotropic

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 analysis does 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 diboride for an internal combustion engine piston The mechanical properties of alloy and Silicon carbide reinforced Zirconium diboride are listed in the following table 1

Table 1 Material Properties

a A Applying Temperatures, Convections and Loads

The piston is divided into the areas defined by a series of grooves for sealing rings The boundary conditions for mechanical simulation were defined as the pressure acting on the entire piston head surface (maximum pressure

in the engine cylinder) It is necessary to load certain data on material that refer to both its mechanical and thermal

properties to do the coupled Thermo-mechanical calculations The temperature load is applied on different areas and

pressure applied on piston head The regions like piston head and piston ring regions are applied with large amount

of heat (160°C-200°C) The convection values on the piston wall ranges from 232W/mK to 1570W/mK The working pressure is 3.3Mpa

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

The results obtained from applying aluminium material for piston are,

Fig 4: Directional Deformation of aluminium piston Fig 5 : Von – Misses strain of aluminium piston

The results obtained from applying Silicon carbide reinforced Zirconium diboride material for piston are,

Fig 6 : Total Deformation of SiC reinforced ZrB2 piston Fig 7: Directional Deformation of SiC reinforced ZrB2 piston

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

Fig 12 : Total Heat flex of SiC reinforced ZrB2 piston Fig 13 : Directional Heat flex of SiC reinforced ZrB2 piston

COMPARISON OF RESULT ON STATIC ANALYSIS IN PISTON

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

( Y Axis )

SiC reinforced

( Y axis )

Von – Misses strain

SiC reinforced

Fig 16: Directional Deformation of aluminium piston Ring Fig 17: Directional Deformation of SiC reinforced ZrB2 piston Ring

Fig 18 : Von – Misses strain of aluminium piston Ring Fig 19 : Von – Misses strain of SiC reinforced ZrB2 piston Ring

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

Fig 22 : Total Heat flex of aluminium piston Ring Fig 23 : Total Heat flex of SiC reinforced ZrB2 piston Ring

COMPARISON OF RESULT ON STATIC ANALYSIS IN PISTON RING

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

Flex ( Y Axis )

SiC reinforced

Piston

Directional deformation

strain

SiC

reinforced

ZrB2

Fig 26 : Total Deformation of aluminium assembly Fig 27 : Total Deformation of SiC reinforced ZrB2 assembly

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

COMPARISON OF RESULT ON STATIC ANALYSIS IN PISTON RING ASSEMBLY

Piston Rings

( Y Axis )

SiC reinforced

Piston Rings

Directional deformation

strain

SiC

reinforced

ZrB2

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

materials and it is observed that the deflections are very less for SiC reinforced ZrB2 Composite material compared to Al-Alloy.

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

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

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

Mode No

Frequency ( Hz ) Piston with Al –alloy

Table 8: Comparisons of first 10 natural frequencies of piston for different material