DESIGN AND ANALYSIS OF MOTOR CYCLE BLOCK

ENGINE USING DIFFERENT MATERIALS

P.Praveen Kumar Reddy1,B.Venkateswar Reddy2
1
Assistant Professor,2Associate Professor, Dept. of Mechanical Engineering
Mahaveer Institute of Science and Technology, Vysapuri, Hyderabad. India.

ABSTRACT

The cylinder block is the largest part of the engine. Its upper section carries the cylinders
and pistons. Normally, the lower section forms the crankcase, and supports the crankshaft.
Cylinder blocks made of aluminum are lighter than cast-iron blocks of the same size. They
usually have cast-iron liners which provide a hard-wearing surface for pistons and piston
rings.
The cylinder block forms the basic framework of the engine, it houses the engine
cylinders, which serve as bearings and guides for the pistons reciprocating in them. The
analysis of the engine block is to be carried out to predict its behavior under static and
dynamic loading. The cylinder block has to withstand the stresses and deformations due to
loads acting on it.
The solid model of the block is generated by using CATIA V5 R19.The n th model is
imported to HYPERMESH-10. The quality mesh is prepared in HYPERMESH for converged
solution and the end solver set as ANSYS in which load and boundary conditions are applied
for analysis. The static analysis is performed to predict the deformations and stresses. The
modal analysis to predict the first five natural frequencies and corresponding mode shapes.
Keywords: cylinder block, Catia V5, Steel,Aluminum,Cast iron,etc..,
1. INTRODUCTION
Due to development of computers and subsequent development of numerical
methods, it is now possible to model the components, simulate the conditions and perform
testing on computer without actual model making, One of the most popular numerical
methods used is the Finite Element (FEM) offered by the existing CAD/CAM/CAE. The
most popular software that is based on Finite Element Analysis is “ANSYS” and
“HYPERMESH” software, which is used in this work.

Altair hypermesh is widely used for meshing. It is almost used in all automobile-
leading industries. For complex geometries it is best suited. The effective mesh generation is
done. The main objective is to check all the element quality checking such as aspect ratio,
war page angle, skew angle, and jacobian. So tetra mesh and mapped mesh of motorcycle
engine block is done. Another objective is to find out the stresses, deformation and natural
frequencies using structural and modal analysis. The material properties and loading
conditions for motorcycle engine block are taken into consideration.
1.1 LITERATURE SURVEY
Weight reduction of automobiles is key technology in order to improve fuel economy
and driving performance. Concerning the motorcycle engine, weight reduction is also the
fundamental and important technologies. Cylinder is one of the main parts of engine and the
wear characteristics of the cylinder liner are largely related to the engine performance. Gray
iron liners squeezed in aluminum cylinder block have been widely used.

Amlesh ramesh Askhedkar(2001).et.al…, Author describes This is due to the

excellent resistance to abrasion of gray iron. In order to realize light all- aluminium cylinder,
the good abrasion- resistant method is necessary to develop to be applied with inner surface
of liners. We have developed the new Rapid Composite Plating System for the motorcycle
engine cylinders. This system made it possible to adopt all- aluminium cylinders without cast
iron liners to new type of engine. [1]

J. P. Brandeis (2000).et.al…, Presents Aluminium is the material for lighter structural

components, and is also advantageous for the purpose of heat transfer. The automotive power
plant requires an efficient material with less weight and proper thermal characteristics, as
demanded by early aviation applications, due to the recent necessity for environmental and
energy conservation. However, cast iron has been the dominant material used for engine
blocks because of simple economic reasons.[2]

SS Rao,et.al.., To overcome the simple cost disadvantages of aluminium engine block

application, it is necessary to utilize the full potential of the material to the proper advantage.
New aluminium engine blocks with a unique cooling system of air assisted water-cooling
were developed.The basic design concept between cast iron and aluminium are the same,
except for the design differences due to the structural stiffness of both materials.[3]

M.Kawasaki,(1999).et.al.., However, there are thermal property differences between

aluminium and cast iron other than stiffness and weight. Therefore, the design method of the
aluminium engine block was altered to take advantage of the thermal property. Practically,
aviation and motorcycle engines use the air-cooled aluminium block because of the lighter
mass and high thermal conductivity of aluminium[4].

Swathi.et.al.., This report describes a unique aluminium engine block for passenger
vehicles. The cooling system is an air assisted water-cooling method; the water jacket was
shortened for upper core and thin fins replace lower part of core to dissipate the heat where
the temperature is relatively low. This yields the reduction of radiator capacity and water
pump size. It has also achieved significant reduction of block mass without loss of
performance. [5]

1.2 PROBLEM INVESTIGATION:

The solid model of the block is generated by using CATIA V5 R19.The n th model is
imported to HYPERMESH-10. The quality mesh is prepared in HYPERMESH for converged
solution and the end solver set as ANSYS in which load and boundary conditions are applied
for analysis. The static analysis is performed to predict the deformations and stresses.
 The modal analysis to predict the first five natural frequencies and corresponding
mode shapes. Identify the right material for application based on deformation and vonmises
stress and natural frequency in modal analysis.

3. GEOMETRIC MODELLING

3.1 Modeling software:

CatiaV5R19 is an interactive Computer- Aided Design and Computer Aided

Manufacturing system. The CAD functions automate the normal engineering, design and
drafting capabilities found in today’s manufacturing companies. The CAM functions provide
NC programming for modern machine tools using the CatiaV5 R19 design model to describe
the finished part. CatiaV5 R19 functions are divided into “applications” of common
capabilities. These applications are supported by a prerequisite application called “CatiaV5
R19 Gateway”.

CatiaV5R19 is fully three dimensional, double precision system that allows to

accurately describing almost any geometric shape. By combining these shapes, one can
design, analyze, and create drawings of products.

3.2 Creation of Solid Bodies

We can create solid bodies by sweeping sketch and non-sketch geometry to create
associative features or Creating primitives for the basic building blocks, then adding more
specific features (for example, holes and slots). Sweeping sketch and non-sketch geometry
lets us to create a solid body with complex geometry. This method also gives us total control
over the editing of the body. Editing is done by changing the swept creation parameters or by
changing the sketch. Editing the sketch causes the swept feature to update to match the
sketch.

Figure 3.1 Top portion of motorcycle engine block

Table 3.1: Material properties

Material Density Young’s Poisson’s ratio Yield

modulus strength
(Kg/mm^3) (N/mm^2) (MPa)

Aluminium 2700e-9 0.675e5 0.34 300

Grey cast iron 7000e-9 0.75e5 0.27 ---

Steel 7850e-9 2e5 0.3 650

Titanium 4500e-9 1.1e5 0.33 1050

Brass 8500e-9 1e5 0.34 300

3.3 Overview of steps in modal analysis

The procedure for modal analysis consists of four main steps i.e., Build the model, apply
loads and obtain the solution, expand the modes and review the results
3.4 Mode Extraction Methods
Subspace method : subspace method internally uses subspace iteration technique, which
internally uses the generalized jacobi iteration algorithm. It is highly accurate because it uses
full K and M matrices. It is slower that reduced method. This method is typically used in the
cases where high accuracy is required or wherever selecting master degrees of freedom is
practical.
Block lanczos method, Power dynamics method & Reduced method.
4. RESULTS AND DISCUSSIONS
4.1. Static Analysis Results
The static analysis of engine block is performed on the model imported to ansys from
hypermesh as shown in figure 4.1 using five different materials.
 Figure 4.1 Finite element model imported to ansys from hypermesh

Figure 4.2 Boundary conditions applied for the engine block

In Figure 4.2 shows the boundary conditions applied on the motorcycle engine block
The area shown in light blue colour indicates the area where the block is constrained. The red
colour area indicates the area where the pressure is applied. The value of pressure applied is
4.5MPa.

Figure 4.3 Deformation after analysis of engine block using aluminium

In Figure 4.3 shows the deformation of the aluminium engine block. Pressure of
4.5MPa is applied on the block. The displacement is taken in z-direction the value of
deformation after applying the pressure is 0.036226 mm.
 Figure 4.4 Vonmises stress after analysis of engine block using aluminium

In Figure 4.4 shows the stresses in the aluminium engine block. The minimum stress
is near the bottom portion of the engine block. The stress induced near the fins is 24.218MPa.
The stress induced near the outer surface of the cylinder is 60.545MPa. The maximum stress
induced is 108.981MPa.

Figure 4.5 The weakest point of the aluminium engine block

In Figure 4.5 shows the point indicated by the arrow, which is the weakest point of the
aluminium engine block since the stress induced is maximum at this point, which is 108.981
MPa.
Table 4.1 Deformations, stresses and factor of safety obtained for engine block using
different materials

S.No. Material Deformation (mm) Vonmises stress (MPa)

1 Aluminium 0.036226 108.981

2 Grey cast iron 0.079944 447.69

3 Steel 0.047982 422.723

4 Titanium 0.085615 413.546

5 Brass 0.093964 410.356

The deformation value for aluminium engine block is 0.036226mm,the maximum

stress is 108.981MPa and the factor of safety is 2.75,the deformation value for grey cast iron
engine block is 0.079445 and the maximum stress value is 447.69MPa since grey cast iron
does not have yield strength we cannot determine the factor of safety, the deformation value
for steel engine block is 0.046982mm,the maximum stress value is 413.546MPa and the
factor of safety is 1.53,the deformation for titanium engine block is 0.085625mm,the
maximum stress value is 413.546MPa and the factor of safety is 2.54,the deformation value
for brass engine block is 0.093964mm and the factor of safety is 0.73.After comparing all the
materials, aluminium is chosen as the suitable material since it has the least stress induced
whose value is less than the yield strength value. The factor of safety for aluminium block is
2.75, which is within the allowable limit.

Figure 4.6 deformations of materials

 Figure 4.7 vonmises stress of materials
4.2. Modal Analysis

Mode of vibration, Hz

Material 1 2 3 4 5

Aluminium 58 65 67 74 85

Grey cast
50 54 55 62 75
iron

Steel 49 56 58 64 74

Titanium 52 58 60 66 76

Brass 39 44 45 50 58

Modal analysis has been performed for the engine block using five different materials, and
first five mode frequencies are shown in the table 4.2.

Table 4.2: Natural frequencies of engine block for different materials

The five natural frequencies of different materials are shown in the above table. The
frequencies for aluminium engine block are obtained between 58Hz to 85Hz,the frequencies
for grey cast iron engine block are obtained between 50Hz to 75Hz,the frequencies for steel
engine block are obtained between 59Hz to 74Hz, the frequencies for titanium engine block
are obtained between 52Hz to 76Hz and the frequencies for brass engine block are obtained
between 39Hz to 58Hz.
 Figure 4.8 Mode-1 shape for aluminium engine block

Mode shapes for the first four natural frequencies of aluminium block are given in the
Figure 4.8. The frequency for the first mode shape is 58Hz,frequency for the second mode
shape is 65Hz,frequency for the third mode shape is 67Hzand frequency for the fourth mode
shape is 74Hz.

Figure 4.9. aluminium with different modes

From the above figure 4.9 shown the frequency for the first mode shape is
58Hz,frequency for the second mode shape is 65Hz,frequency for the third mode shape is
67Hz ,frequency for the fourth mode shape is 74Hz and frequency of fifth mode is 85Hz.

From the figure 5.40 the frequency for the first mode shape is 39Hz,frequency for the second
mode shape is 44Hz,frequency for the third mode shape is 45Hz,frequency for the fourth
mode shape is 50Hz and frequency of fifth mode is 58Hz.
The natural frequencies of different materials are aluminium engine block are
obtained between 58Hz to 85Hz, the frequencies for grey cast iron engine block are obtained
between 50Hz to 75Hz, the frequencies for steel engine block are obtained between 59Hz to
74Hz, the frequencies for titanium engine block are obtained between 52Hz to 76Hz and the
frequencies for brass engine block are obtained between 39Hz to 58Hz.In these aluminium
has the highest excitation it is best of the material compare to other materials.

6.0 CONCLUSION
1. The FEA packages used for simulation with various types of loads, which can be used
to understand the various types of boundary conditions.
2. The deformations of engine block are obtained for different materials out of which
aluminium has the least deformation, which is 0.036226mm.Based on these values for
the static analysis; the design of motorcycle engine block is safe based on the rigidity
criteria.
3. The vonmises stresses are obtained for different materials out of which the stress
induced in aluminium block is less, which is 108.981MPa. Based on the design
criteria this value is less than the yield strength value and factor of safety is less,
hence the design is safe based on strength criteria.
4. The modal analysis using lancoz’s algorithm is performed to predict five natural
frequencies and their corresponding mode shapes of five different materials out of
which aluminium has the highest excitation.
5. The frequencies for the aluminium engine block are 58Hz, 65Hz, 67Hz, 74Hz and
85Hz.

REFERENCES
1. Amlesh ramesh Askhedkar- ‘’Application of Computer Simulation Using Fem and
Experimental Techniques for the Reduction of Noise in Air-Cooled Engine and
Crankcase Cover of Motorcycle’’, Automotive Res. Assoc. of India, Vol2,
2001,pp151-155.
2. J. P. Brandeis ‘’The Use of Finite Element Techniques to Predict Engine Vibration’’
Renault Technical Research, 2000,pp 99- 101
3. S.S Rao , ”The Finite Element method in Engineering”, BH Publications New
Delhi,3rd Edition,1999.
4. M.Kawasaki,et al. “Development of Engine. Valve Seats Directly Deposited on to
Aluminium Cylinder Head by Laser Cladding Process”, SAE paper 920571 (1992).
5. Swati M. Athavale, Prabhakar Raghunath Sajanpawar,‘’Analytical Studies on
Influence of Crankshaft Vibrations on Engine Noise Using Integrated Parametric
Finite Element Model’’ Automotive Res. Assoc. of India, 1999,p45-47
6. Anonymous, “Aluminium Cylinder Block for General Motors Truck/SUV engines,”
A Design Study in Aluminium Casings, pp. 1-31.
7. United States 1 Patent Ackerman et al. Inventors: Allen D. Ackerman, Troy; Howard
A. Aula, Dearborn Hgts., both of Mich. Assignee: Ford Motor Company, Dearborn,
Mich.