design, analysis and optimization of silumin piston by using pro-e and ansys

International Journal of Advanced Scientific Research & Development (IJASRD)

p-ISSN: 2394-8906 | e-ISSN: 2395-6089

www.ijasrd.org, Volume 02, Issue 02 (Apr – Jun’ 2015), PP 20 – 33

© IJASRD, All Rights Reserved 20 | P a g e

Design, Analysis and Optimization of Silumin Piston by using

Pro-E and Ansys A. Karthick1

ABSTRACT: The main objective of this paper is to explore the analysis of a piston with design

change to attain less volume and better efficiency and also to make a comparison of earlier

used piston material Al-Mg-Si alloys with new material silumin on the basis of static

structural and transient thermal analysis. A proper Finite Element Model is developed using

Cad software Pro/E Wildfire 5.0. In this project we are optimizing the material of the piston.

This project we are analyzing the pressure acting on the piston by the two materials.

Presently the piston are made by the material of AL-Mg-Si, this project we are testing the

same load under SILUMIN. Then the thermal analysis is done to determine the total heat flux

in the existing piston for the given temperature conditions by using ANSYS 11. The

temperature acting on the surface of the piston is applied. The results were also used to

determine the total heat flux for a particular material. The results are to be tabulated

between the piston designs before optimization and after optimization for Al-Mg-Si and

silumin.

KEYWORDS - AL-Mg-Si (aluminium, magnesium, silumini), ANSYS.PRO-E, Thermal conductivity, Specific

heat

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

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

an engine its purpose is to transfer from expanding gas in the cylinder to the crank shaft via

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

gas pressure and inertia forces at work and this working condition may cause the fatigue

damage of the piston. The investigations indicate that greatest stress appears on the upper

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

An Internal Combustion Engine is that kind of prime mover that converts chemical

energy to mechanical energy. The fuel on burning changes into gas which impinges on the

piston and pushes it to cause reciprocating motion. The reciprocating motion of the piston is

then converted into rotary motion of the crankshaft with the help of connecting rod.

IC engines are used in marine, locomotives, aircrafts, automobiles and other industrial

applications.

Research object – Piston

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

1 PG Scholar, Department of Mechanical Engineering, Anna University, Chennai, India.

http://www.ijasrd.org/

Design Analysis and Optimization of Silumin Piston by using PRO-E and ANSYS


transfer force from expanding gas in the cylinder to the crankshaft via a piston rod.

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

cracks and so on.

Model of piston

Piston in an IC engine must possess the following characteristics:

Strength to resist gas pressure. Must have minimum weight.

Must be able to reciprocate with minimum noise.

Must have sufficient bearing area to prevent wear.

Must seal the gas from top and oil from the bottom.

Must disperse the heat generated during combustion.

Must have good resistance to distortion under heavy forces and heavy temperature.

Material properties

2.1 Existing material of piston: Aluminium Alloy

Aluminium alloys typically have an elastic modulus of about 70 GPa, which is about

one-third of the elastic modulus of most kinds of steel and steel alloys. Therefore, for a given

load, a component or unit made of an aluminium alloy will experience a greater elastic

deformation than a steel part of the identical size and shape. Though there are aluminium

alloys with somewhat-higher tensile strengths than the commonly used kinds of steel, simply

replacing a steel part with an aluminium alloy might lead to problems.

With completely new metal products, the design choices are often governed by the

choice of manufacturing technology. Extrusions are particularly important in this regard,

owing to the ease with which aluminium alloys, particularly the Al–Mg–Si series, can be

extruded to form complex profiles.

In general, stiffer and lighter designs can be achieved with aluminium alloys than is

feasible with steels. For instance, consider the bending of a thin-walled tube: the second

moment of area is inversely related to the stress in the tube wall, i.e. stresses are lower for

larger values. The second moment of area is proportional to the cube of the radius times the

wall thickness, thus increasing the radius (and weight) by 26% will lead to a halving of the

wall stress. For this reason, bicycle frames made of aluminium alloys make use of larger tube

diameters than steel or titanium in order to yield the desired stiffness and strength. In

automotive engineering, cars made of aluminium alloys employ space frames made of

extruded profiles to ensure rigidity. This represents a radical change from the common

approach for current steel car design, which depend on the body shells for stiffness that is a

unibody design.


http://en.wikipedia.org/wiki/Pascal_(unit)

http://en.wikipedia.org/wiki/Steel_alloy



Aluminium alloys are widely used in automotive engines, particularly in cylinder

blocks and crankcases due to the weight savings that are possible. Since aluminium alloys are

susceptible to warping at elevated temperatures, the cooling system of such engines is

critical.

Manufacturing techniques and metallurgical advancements have also been

instrumental for the successful application in automotive engines. In the 1960s, the

aluminium cylinder heads of the Corvair earned a reputation for failure and stripping of

threads, which is not seen in current aluminium cylinder heads.

An important structural limitation of aluminium alloys is their lower fatigue strength

compared to steel. In controlled laboratory conditions, steels display a fatigue limit, which is

the stress amplitude below which no failures occur – the metal does not continue to weaken

with extended stress cycles. Aluminum alloys do not have this lower fatigue limit and will

continue to weaken with continued stress cycles. Aluminium alloys are therefore sparsely

used in parts that require high fatigue strength in the high cycle regime (more than 107 stress

cycles). Al-Mg-Si alloys are widely used as medium-strength structual material alloys. In the

continuing drive for automobile weight reduction, Al-Mg-Si alloys are considered to be the

most promising candidates for heat tretable bodysheet materials. In the manufacturing

process, these alloys are subject to room temperature aging and artificial aging at around 175

C during an elevated temperature paint-bake sysle. Thus, detailed studies on the two step

aging behavior are strongly desired. In the 6000 series of alloys, Mg and Si are added either

in balanced amounts to form quasi-binary Al-Mg2Si alloys or with an excess of Si above the

quasi-binary composition. Recent studies have shown that alloys containing an excess of Si

above probounced age hardening effects, while age hardening after room temperature aging

is significantly suppressed.

Two alloys were examined, one having a quasi-binary Al-Mg2Si composition, Al-

0.70Mg-0.34Si (at.%) and the other containg an excess of Si, Al-0.65Mg-0.70Si (at.%).

These alloys were solution treated at 550 C for 30min. and subsequently ice-water quenched.

The solution treated samples were subject to various heat treatments including room

temperature ageing, artificial ageing at 175 C and two step ageing. The resulting

microstructures were examined by transmission electron microscopy (TEM) and APFIM.

Evdence for Mg clusteing in Si excess alloy as- quenched was found. After room

temperature aging for 70 days, clusters of Mg, Si and their co-clusters were idetified as

previously reported [2]. In the specimen aged at 175 C for 30 min., small equiaxed Mg-Si

precipitates are observed by TEM. APFIM results show that the ratio of Mg to Si atoms in the

precipitates is close to 1, rather than 2 which is expected from the equilibrium concentration

of Mg2Si.

Material properties of Al-Mg-Si

SL.NO MATERIAL PROPERTIES VALUE

1 Young’s modulus 2.3e+005 MPa

2 Possion’s ratio 0.24

3 Density 2.707e-006 kg/mm3

4 Thermal conductivity 0.77 W/mm.oc

5 Specific heat 892 j/kg.oc


http://en.wikipedia.org/wiki/Screw_thread

http://en.wikipedia.org/wiki/Fatigue_limit



New material of Piston: Silimin

Silumin is the name that is used in some countries for alloys based on Al–Si system.

Silumin is a series of lightweight, high-strength aluminium alloys with silicon content within

range of 3–50%. Most of these alloys are casting ones, but also it would be produce by rapid

solidification processes and powder metallurgy. Within the Aluminum Association

designation system silumins are corresponding to alloys of two system: 3xx.x – Aluminum–

silicon alloys are also containing magnesium and/or copper and 4xx.x – Binary aluminum–

silicon alloys. Among the advantages of silumin is its high resistance to corrosion, making it

useful in humid environments. The addition of silicon to aluminium also makes it less

viscous when liquid, which together with its low cost (both component elements are

relatively cheap to extract), makes it a very good casting alloy and a fresher metal. It is also

used on 3 phase motors to allow speed regulation. Another use is rifle scope mounts and

camera mounts.

The general name for a group of aluminumbase casting alloys containing silicon(413

percent; up to 23 percent in certaingrades). The group is alloyed with Cu, Mn, and Mg and so

metimes with Zn, Ti, Be, and other metals, depending on the desiredcombination of fabricatin

g characteristics and operational performance. Silumin alloys are noted for their high resistan

ce to corrosion in humid and marine atmospheres. They are used in themanufacture of compo

nents with complex shapes, mainly in automotive vehicle and aircraft manufacture. The USS

R producessilumin alloys under such trade names as AL2, AL4, and AL9.

Silumin is a series of lightweight, high-strength aluminium alloys with silicon content

between 4% and 22%. Among the advantages of silumin is its high resistance to corrosion,

making it useful in humid environments. The addition of silicon to aluminium also makes it

more fluid when liquid, which together with its low cost (both component elements are

relatively cheap to extract), makes it a very good casting alloy

High castability, high fluidity, high corrosion resistance, high ductility, low specific

gravity, high machinability

Used for large castings, which are to operate under heavy load conditions

Under the category of non-heat-treatable alloys but can be modified by the addition of

Mg & Cu, which enables it to be heat treated, e.g. AΠ4 alloys

Strengthened by solution treatment, e.g. adding 0.01% Na (in form NaF & NaCl) to

the melt just before casting

Disadvantage is the presence of porosity in the cast (forms foams), which can be

avoided by casting under pressure in autoclaves

Examples: AΠ2 &AΠ4 alloys 15

Material properties of Silumin

SL.NO MATERIAL PROPERTIES VALUE

1 Young’s modulus 3.17e+005 MPa

2 Possion’s ratio 0.27

3 Density 2.659e-006 kg/mm3

4 Thermal conductivity 0.134 W/mm.oc

5 Specific heat 867 j/kg.oc


http://en.wikipedia.org/wiki/Corrosion

http://en.wikipedia.org/w/index.php?title=Fresher_metal&action=edit&redlink=1



Design Calculation

Design calculation of piston before optimization.

Thickness of Piston Head (th)

The piston thickness of piston head calculated using the following Grashoff’s

formula, tH = 2t) in mm

Where

P= maximum pressure in N/mm²

D= cylinder bore/outside diameter of the piston in

t=permissible tensile stress for the material of

the piston.

Here the material is a particular grade of AL-Si alloy whose permissible stress is 50

Mpa-90Mpa.

Before calculating thickness of piston head, the diameter of the piston has to be

specified. The piston size that has been considered here has a L*D specified as

152*140.

, tH 2)/(16 * 160) in mm

tH = 60 mm

Radial Thickness of Ring (t1)

t1 w t

Where D = cylinder bore in mm

t1

Pw= pressure of fuel on cylinder wall in N/mm². Its value is limited from 0.025N/mm² to

0.042N/mm². For present mater t t is 90Mpa

Axial Thickness of Ring (t2)

The thickness of the rings may be taken as

t2 = 0.7t1 to t1 Let assume

t2 =5mm

Min axial thickness

(t2) =D/( 10*nr )

Where nr = number of rings

t 2 = 0.7 * 5.24

t 2 = 3.46 mm

Width of the top land (b1)

The width of the top land varies

b1 = tH to 1.2 tH

b1 = 1.2 *8.6

b1= 10.84 mm




Width of other lands (b2)

Width of other ring lands varies

b2 = 0.75t2 to t2

b2 = 0.75*3.46

b2 = 4 mm

Maximum Thickness of Barrel (t3)

t3 = 0.03*D + b + 4.5 mm

Where

b = Radial depth of piston ring groove

t3 = 0.03*160 + 4 + 4.5

t3 = 14.34 mm

Design specification before optimization

S.No. Dimensions Size in mm

1 Length of the Piston(L) 152

2 Cylinder bore/outside diameter of the piston(D) 140

3 Radial thickness of the ring (t1) 5.24

4 Axial thickness of the ring (t2) 5

5 Maximum thickness of barrel (t3) 14.34

6 Width of the top land (b1) 10.84

7 Width of other ring lands (b2) 4

Design calculation of piston after optimazation

Thickness of Piston Head (th)

The piston thickness of piston head calculated using the following Grashoff’s

formula, tH = 2t) in mm

Where, P= maximum pressure in N/mm²

t =permissible tensile stress

for material of the piston.

Here the material is a particular grade of AL-Si alloy whose permissible stress is 50

Mpa-90Mpa. Before calculating thickness of piston head, the diameter of the piston has to be

specified. The piston size that has been considered here has a L*D specified as 152*140.

tH 2)/(16 * 160) in mm

tH = 60 mm




Radial Thickness of Ring (t1)

t1 w t

Where D = cylinder bore in mm

t1

t1=3.46mm

Pw= pressure of fuel on cylinder wall in N/mm². Its value is limited from

t is 90Mpa

Axial Thickness of Ring (t2)

The thickness of the rings may be taken as

t2 =0.7t1 to t1 Let

assume t2 =5mm

Min axial thickness (t2) = D/ (10*nr)

Where, nr = number of rings

t2 = 0.7 * 5.1

t2 = 3.52 mm

Width of the top land (b1)

The width of the top land varies

b1 = tH to 1.2 tH

b1 = 1.2 *8.2

b1=9.36mm

Width of other lands (b2)

Width of other ring lands varies from

b2 = 0.75t2 to t2

b2 = 0.75*3.2

b2 = 3.24 mm

Maximum Thickness of Barrel (t3)

t3 = 0.03*D + b + 4.5 mm

b = Radial depth of piston ring groove

t3 = 0.03*160 + 4 + 0.4

t3 = 9.08 mm

Design specification after optimization:

S.No. Dimensions Size in mm

1 Length of the Piston(L) 152

2 Cylinder bore/outside diameter of the piston(D) 140

3 Radial thickness of the ring (t1) 3.46

4 Axial thickness of the ring (t2) 3.52

5 Maximum thickness of barrel (t3) 9.08

6 Width of the top land (b1) 9.36

7 Width of other ring lands (b2) 3.24




Modeling Software: Pro-E

Pro/ENGINEER, PTC's parametric, integrated 3D CAD/CAM/CAE solution, is used

by discrete manufacturers for mechanical engineering, design and manufacturing. Created by

Dr. Samuel P. Geisberg in the mid-1980s, Pro/ENGINEER was the industry's first successful

parametric, 3D CAD modeling system. The parametric modeling approach uses parameters,

dimensions, features, and relationships to capture intended product behavior and create a

recipe which enables design automation and the optimization of design and product

development processes. This powerful and rich design approach is used by companies whose

product strategy is family-based or platform-driven, where a prescriptive design strategy is

critical to the success of the design process by embedding engineering constraints and

relationships to quickly optimize the design, or where the resulting geometry may be complex

or based upon equations. Pro/ENGINEER provides a complete set of design, analysis and

manufacturing capabilities on one, integral, scalable platform. These capabilities, include

Solid Modeling, Surfacing, Rendering, Data Interoperability, Routed Systems Design,

Simulation, Tolerance Analysis, and NC and Tooling Design.

Modelling sketch of conventional piston

Modelling sketch of optimized piston

Analysis software: ANSYS

ANSYS is an engineering simulation software provider founded by software engineer

John Swanson. It develops general-purpose finite element analysis and computational fluid

dynamics software. While ANSYS has developed a range of computer-aided engineering

(CAE) products, it is perhaps best known for its ANSYS Mechanical and ANSYS

Multiphysics products.

ANSYS Mechanical and ANSYS Multiphysics software are non-exportable analysis

tools incorporating pre-processing (geometry creation, meshing), solver and post-processing




modules in a graphical user interface. These are general-purpose finite element modeling

packages for numerically solving mechanical problems, including static/dynamic structural

analysis (both linear and non-linear), heat transfer and fluid problems, as well as acoustic and

electro-magnetic problems.

ANSYS Mechanical technology incorporates both structural and material non-

linearities. ANSYS Multiphysics software includes solvers for thermal, structural, CFD,

electromagnetics, and acoustics and can sometimes couple these separate physics together in

order to address multidisciplinary applications. ANSYS software can also be used in civil

engineering, electrical engineering, physics and chemistry.

ANSYS, Inc. acquired the CFX computational fluid dynamics code in 2003 and

Fluent, Inc. in 2006. The CFD packages from ANSYS are used for engineering simulations.

In 2008, ANSYS acquired Ansoft Corporation, a leading developer of high-performance

electronic design automation (EDA) software, and added a suite of products designed to

simulate high-performance electronics designs found in mobile communication and Internet

devices, broadband networking components and systems, integrated circuits, printed circuit

boards, and electromechanical systems. The acquisition allowed ANSYS to address the

continuing convergence of the mechanical and electrical worlds across a whole range of

industry sectors.

Analysis result of conventional aluminum alloy piston:

Meshing Static analysis based on deformation

Static analysis based on equivalent stress Transient thermal analysis




Transient thermal analysis based on total heat flux

Analysis result of conventional silumin piston:







Analysis result of optimized aluminum alloy piston:




Output value comparison of conventional Al-Mg-Si and Silumin

Material Limit Total

deformation

Equivalent

elastic strain

Equivalent

stress Temperature

Total

heat

flux

AL-Mg-Si

MIN 0. mm 2.3023e-006

mm/mm

7.5174e-002

MPa 295.25 K

5.795e-

006

W/mm2

MAX

1.3582e-002

mm

5.8744e-004

mm/mm

35.919 MPa 473.15 K 3.5272

W/mm2




Silumin

MIN 0. mm 5.021e-007

mm/mm

1.7683e-002

MPa 295.22 K

3.654e-

006

W/mm²

MAX

3.0184e-003

mm

1.4059e-004

mm/mm 37.405 MPa 473.15 K

3.0913

W/mm²

Output value comparison of optimized Al-Mg-Si and Silumin:

Material Limit Total

deformation

Equivalent

elastic strain

Equivalent

stress Temperature

Total

heat flux

Al-Mg-Si

MIN 0. mm 2.4242e-006

mm/mm

3.5138e-002

MPa 295.25 K

2.579e-

006

W/mm²

MAX 1.8886e-002

mm

5.9023e-004

mm/mm 37.247 MPa 473.15 K

3.5561

W/mm²

Silumin

MIN 0. mm 5.3167e-007

mm/mm

4.6875e-002

MPa 295.21 K

1.5269e-

006

W/mm²

MAX 4.2191e-003

mm

1.4034e-004

mm/mm 38.686 MPa 473.15 K

3.1188

W/mm²

Conclusion

In this work the following results were obtained. The design of piston before and after

the optimization are done properly on the basic design procedure and their material

properties. The modelings of those pistons are also done with the help of 3d modeling

software PRO-E. The analysis of the before and after optimized piston are done for the

existing material AL-Mg-Si and the new material silumin with the help of analysis software

ANSYS. In ansys, the structural and thermal analysis are to be done with the help of

importing the PRO-E model into ANSYS software. Then comparing the results of before and

after optimized piston for the materials AL-Mg-Si and silumin. With their comparing results

the new optimized silumin performance is very well when compared to the existing AL-Mg-

Si piston on the basic of stress, strain and total heat flux.

References

[1] A.Atish Gawale, A. Shaikh and Vinay Patil, “Nonlinear Static Finite Element Analysis and

Optimization of connecting rod World, Journal of Science and Technology, Vol. 2(4), pp .01-

04, 2012.

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Finite Element Method, International

Journal of Modern Engineering Research (IJMER), Vol.2, Issue.4, pp.2919-2921, 2012.

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A390 and Ductile Iron 65-45-12 Under Service Conditions, 5th International Conference on

Mechanics and Materials in Design Porto-Portugal, 24- 26, pp .1-21,2006.

[6] C.H. Li, Piston thermal deformation and friction considerations, SAE Paper, vol. 820086, 1982.

[7] Properties and Selection: Irons, steels and high performance alloy, ASM Handbook, vol. 1, ASM

International, 1990.

[8] A.C. Alkidas, Performance and emissions achievements with an uncooled heavy duty, single

cylinder diesel engine, SAE, vol. 890141,1989.

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870020, 1987.

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Biographical Note:

Mr. A. Karthick is a final year post graduate students from Sembodai

R.V. Engineering College, Sembodai, Vedharaniyam, Nagapattinam. He

perusing his M.E. degree in (CAD/CAM).


design, analysis and optimization of silumin piston by using pro-e and ansys

Education

engine piston

piston rod

piston rings

existing piston

piston designs

optimization of silumin

research object piston

material of al