International Journal on Mechanical Engineering and Robotics (IJMER)
________________________________________________________________________________________________
Dynamic Analysis of a Connecting Rod Using FEA
1
G. Sailaja, 2S. Irfan Sadaq, 3Shaik Vaseem Yunus
1,2,3
MED, Muffakham Jah College of Engineering and Technology, Hyderabad.
connecting rods help to decrease lead caused by forces
Abstract- Connecting rod acts as a moderator in between
the crank and piston. Its primary function is to convert of inertia in engine as it does not require big balancing
linear motion into reciprocating motion by transmit the weight on crankshaft. Application of metal matrix
pull and push from the piston to crank. Connecting rods composite enables safety increase and advances that
are generally made with carbon steel and aluminium alloys leads to effective use of fuel and to obtain high engine
because of high strength and stiffness. In the present work, power. Honda Company had already started the
static and modal analysis is carried out to determine the manufacturing of aluminium connecting rods reinforced
dynamic behaviour of connecting rod by considering with steel continuous fibres. By carrying out these
deformation, strain and stresses when made with modifications to engine elements will result in effective
Beryllium alloy using Ansys software. These parameters
reduction of weight, increase of durability of particular
help in identifying a section of failure due to stresses
induced. part, will lead to decrease of overall engine weight,
improvement in its traction parameters, economy and
Keywords: Connecting Rod, Beryllium alloy, Ansys, ecological conditions such as reduction in fuel
Failure stress. consumption and emission of harmful substances into
I. INTRODUCTION atmosphere K. Sudershan kumar [1] et al, described
modelling and analysis of Connecting rod. In his project
Every Internal Combustion (I.C.) engine consists of carbon steel connecting rod is replaced by aluminium
mainly cylinder, piston, connecting rod, crank and crank boron carbide connecting rod. Aluminium boron carbide
shaft. The Connecting Rod is one of the important parts is found to have working factory of safety is nearer to
of an engine. Its work is to transmit the thrust of piston theoretical factory of safety, to increase the stiffness by
from piston pin generated by the burnt gas’s pressure to 48.55% and to reduce stress by 10.35%. Vivek. C.
the other part of engine called Crank via crank pin. Pathade [2] et al, he dealt with the stress analysis of
Connecting rod undergoes high cyclic load of order 10 8 connecting rod by finite element method using pro-e
to 109 . It has two ends one is called small or piston end wild fire 4.0 and Ansys work bench 11.0 software. And
and other one is big or crank end. The big end make a concluded that the stress induced in the small end of the
joint with crank or crank shaft by crank pin and small connecting rod are greater than the stresses induced at
end make a joint with piston by piston pin. It gives the the bigger end, therefore the chances of failure of the
rotating motion to the crank shaft by converting the connecting rod may be at the fillet section of both end.
reciprocating motion of piston into rotating motion. The Pushpendra kumar Sharma [3] et al, performed the static
connecting rod should be such that which can be FEA of the connecting rod using the software and said
withstand the maximum load without any failure during optimization was performed to reduce weight. Weight
high cycle fatigue in operation. The fracture toughness can be reduced by changing the material of the current
also should be such that it does not go below a certain forged steel connecting rod to crack able forged steel
minimum limit. A further need is that the connecting rod (C70). And the software gives a view of stress
should not buckle during operation. These requirements distribution in the whole connecting rod which gives the
are used to select an appropriate cross section and information that which parts are to be hardened or given
material for manufacture connecting rod is the attention during manufacturing stage. Ram bansal [4] et
intermediate link between the piston and the crank. And al, in his paper a dynamic simulation was conducted on
is responsible to transmit the push and pull from the a connecting rod made of aluminium alloy using FEA.
piston pin to crank pin, thus converting the reciprocating In this analysis of connecting rod were performed under
motion of the piston to rotary motion of the crank. dynamic load for stress analysis and optimization.
Connecting rod, automotives should be lighter and Dynamic load analysis was performed to determine the
lighter, should consume less fuel and at the same time in service loading of the connecting rod and FEA was
they should provide comfort and safety to passengers, conducted to find the stress at critical locations.
that unfortunately leads to increase in weight of the
vehicle. This tendency in vehicle construction led the
invention and implementation of quite new materials
which are light and meet design requirements. Lighter
________________________________________________________________________________________________
ISSN (Print) : 2321-5747, Volume-5, Issue-5, 2017
1
International Journal on Mechanical Engineering and Robotics (IJMER)
________________________________________________________________________________________________
II. THEORETICAL CALCULATION OF Table.1: Material Properties of Beryllium Alloy
CONNECTING ROD MATERIAL DENSITY YOUNGS POISSON’S
Pressure calculation: (Kg/m3) MODULUS RATIO
(Gpa)
Consider a 150cc engine Beryllium 8360 131 0.29
Engine type air cooled 4-stroke (Alloy 25)
Bore × Stroke (mm) = 57×58.6 III. FINITE ELEMENT METHOD
Displacement = 149.5CC The finite element method (FEM) is a numerical
technique for solving problems to find out approximate
Maximum Power = 13.8bhp at 8500rpm
solution of a problem which are described by the partial
Maximum Torque = 13.4Nm at 6000rpm differential equations or can also be formulated as
functional minimization. A principle of interest is to
Compression Ratio = 9.35/1
represent as an assembly of finite elements.
Density of petrol at 288.855 K - 737.22*10-9 kg/mm3 Approximating functions in the finite elements are
determined in the terms of the nodal values of a physical
Molecular weight M - 114.228 g/mole
field which is sought.FEM subdivides a whole problem
Ideal gas constant R – 8.3143 J/mol.k or entity into numbers of smaller simpler parts, called
finite elements, and solve these parts for the problems.
From gas equation, The main advantage of FEM is that it can handle
PV=m.Rspecific.T complicated boundary and geometries with very ease.
Where, P = Pressure, V = Volume, m = Mass Steps for the Finite Element Method are:-
Rspecific = Specific gas constant • Modelling the Model
T = Temperature • Import the model
But, • Defining element type
mass = density * volume • Defining material properties
m =737.22E-9*150E3 • Meshing of model
m = 0.11 kg • Applying boundary constrains
Rspecific = R/M • Applying load
Rspecific = 8.3143/0.114228 • Results and Analysing it.
Rspecific = 72.76 IV. FINITE ELEMENT ANALYSIS USING
P = m.Rspecific.T/V ANSYS
P = 0.11*72.786*288.85/150E3 The analysis of connecting rod models are carried out
using ANSYS software using Finite Element Method.
P = 15.4177 MPa Firstly the model files prepared in the SOLID WORKS
P ~ 16 MPA. then is exported to ANSYS software as an IGES files.
One end of rod is fixed and at other end pressure is
applied when performing static analysis and in modal
analysis only one end is fixed and other end is left free
to determine their frequencies. The results are shown in
fig.2 to fig.10.
Fig.1: General dimensions of connecting rod.
Fig.2: Modal analysis at mode shape 2
________________________________________________________________________________________________
ISSN (Print) : 2321-5747, Volume-5, Issue-5, 2017
2
International Journal on Mechanical Engineering and Robotics (IJMER)
________________________________________________________________________________________________
Fig.3: Modal Analysis at mode shape 1 Fig.7: Modal Analysis at mode shape 9
Fig.4: Modal Analysis at mode shape 5 Fig.8: Displacement of connecting rod
The material properties are defined on the model for the
material used as shown in table above. After that, the
meshing of model is to be done. Here a model is divided
into a number of elements and nodes. Once meshing is
done the boundary conditions i.e. DOF constrains,
forces, loads are to be applied on the model. As shown
fig 9, the pressure is applied on the Crank end bearing of
the connecting rod, while keeping piston end fixed. The
pressure of 16MPA is used.
The materials chosen for analysis of the connecting rod
here is Beryllium Alloy. This material was tested using
Fig.5: Modal Analysis at mode shape 8 ANSYS software for the stress and strain and other
forces acting on the connecting rod based on these
material properties shown in the Table1.
V. STRUCTURAL ANALYSIS
Fig.6: Modal Analysis at mode shape 6 Fig.9: Von mises stress of connecting rod at 16MPa
VI. CONCLUSIONS
The static analysis of connecting rod model was
conducted for the Beryllium alloy to identify the fatigue
locations on it. Results of the static analysis output are
shown via stress, strain and deformation under the
applied load. It is observed that the area close to root of
the smaller end is very prone to failure, may be due to
________________________________________________________________________________________________
ISSN (Print) : 2321-5747, Volume-5, Issue-5, 2017
3
International Journal on Mechanical Engineering and Robotics (IJMER)
________________________________________________________________________________________________
higher crushing load due to gudgeon pin assembly. As rod using finite element analysis”, International
the stress value is maximum in this area and stresses are Journal Of advance research in science and
repetitive in nature so chances of fatigue failure are Engineering, Vol. No.1, Issue No. 1,pp – 3367 –
always higher close to this region. Maximum vonmises 3371, September 2012.
stress, Maximum vonmises strain and Maximum
[4] Ram Bhansal, “Dynamic simulation of
displacement are minimum in connecting rod of
connecting rod made of aluminium alloy using
Beryllium alloy. It is observed that stress, strain and
finite element analysis approach”, IOSR Journal
displacement is minimum in beryllium alloy connecting
of Mechanical and civil Engineering, Volume 5,
rod. So, beryllium alloy can be used for production of
Issue 2,pp 01 – 05, Jan – Feb 2013.
connecting rod for longer life.
[5] Ashby, M. F.,Material Selection in Design, 3rd
REFERENCES Edition, Elsevier, 2005.
[1] K, Sudarshan Kumar , Dr. K.Tirupathi Reddy, [6] Sarkate T S, Washimkar S P, Dhulekar S S,
Syed Altaf Hussain “modelling and Analysis of Optimization of Steel connecting rod by
two wheeler connecting rod” , International aluminium using Finite Element Analysis,
Journal of Modern Engineering Research, Vol – Volume 1, Issue 1, 2013.
2, issue – 5, pp – 3367 – 3371, Sep – Oct – 2012.
[7] Kuldeep B, Arun L.R, Mohammed Faheem,
[2] Vivek. C. Pathade, Bhumeshwar Patel, Ajay N, Analysis and optimization of connecting rod
Ingale “Stress Analysis Of I. C. Engine using alfasic composites, (IJIRSET) - Volume 2,
connecting rod by FEM”, International Jounral of Issue 6,June 2013,ISSN: 2319 – 8753.
Engineering and Innovative Technology, Vol –
1, Issue – 3, pp – 12 – 15, March 2012. [8] Prateek Joshi, Mohammad UmairZaki, Static
Stress Analysis of Connecting Rod Using Finite
[3] Pushpendra Kumar Sharmai, Borse Rajendra R, Element Approach,( IOSR-JMCE)-Volume 10 ,
“Fatigue analysis and optimisation of connecting Issue 1, (Nov. - Dec. 2013).
________________________________________________________________________________________________
ISSN (Print) : 2321-5747, Volume-5, Issue-5, 2017
4
