static analysis of connecting rod in a single …static analysis of connecting rod in a single...

STATIC ANALYSIS OF CONNECTING ROD IN A SINGLE

CYLINDER DIESEL ENGINE

1S.KALIAPPAN

2G R Vignesh

3 N R Vigneshwaran

4R Giritharan

5 Dr.T.Mothilal

6 M.D.Rajkamal

1 Associate Professor, Department of Mechanical Engineering, Velammal Institute of Technology , Chennai, India.

[email protected]

234 UG Student,Department of Mechanical Engineering , Velammal Institute of Technology , Chennai, India.

5 Professor, Department of Mechanical Engineering, Velammal Institute of Technology , Chennai, India.

6 Assistant Professor, Department of Mechanical Engineering, Velammal Institute of Technology , Chennai, India.

ABSTRACT Connecting Rods are generally used in automobile

engines, acting as an intermediate link between the piston and the

crankshaft of an engine, which helps in converting the reciprocating

motion of the piston to the rotary motion to the crankshaft. Generally

connecting rods are made using carbon steel and aluminum alloys. In

our project, we are comparing the factors such as von mises stress,

maximum shear stress, maximum principal stress and total

deformation of aluminium alloys, titanium and a copper alloy. FEA

analysis is carried out by considering three materials. The parameters

like various three stresses, and deformation are obtained from

ANSYS software.

KEY WORDS: Von mises stress, Maximum shear stress,

Maximum principal stress, Total deformation.

I. INTRODUCTION

Every Internal Combustion (I.C.) engine consists of mainly

cylinder, piston, connecting rod, crank and crank shaft. The

Connecting Rod is one of the important parts of an engine. A

single-cylinder engine is a basic piston engine configuration of

an internal combustion engine. It is often seen on motorcycles,

motor scooters, dirt bikes, go-karts, and has many uses in

portable tools and garden machinery. Characteristics of

Single-cylinder engines are simple and compact, and will

often deliver the maximum power possible within a given

envelope. In the basic arrangement they are prone to vibration

though in some cases it may be possible to control this with

balance shafts. A connecting rod is a shaft which connects a

piston to a crank or crankshaft in a reciprocating engine.

Together with the crank, it forms a simple mechanism that

converts reciprocating motion into rotating motion. A

connecting rod may also convert rotating motion into

reciprocating motion. Earlier mechanisms, such as the chain,

could only impart pulling motion. Being rigid, a connecting

rod may transmit either push or pull, allowing the rod to rotate

the crank through both halves of a revolution. Vibration is a

mechanical phenomenon whereby oscillations occur about an

equilibrium point. The oscillations may be periodic, such as

the motion of a pendulum or random. There are generally two

categories for the vibrations the free vibrations and forced

vibrations, free vibrations occur when the system is under the

action of oscillating systems and their inherent forces external

forces there are uncertain. All systems that have mass and

elasticity can be free vibrations, the vibrations that occur in

the absence of external stimulus. Vibrations that occur under

uncertain foreign forces are called forced vibrations, when the

uncertain operating system is oscillating with frequency,

oscillation can be uncertain if the impulse frequency of the

system natural frequency is resonance mode occurs and may

be dangerous, there are large fluctuations. Natural frequency is

the frequency at which a system tends to oscillate in the

absence of any driving or damping force. Free vibrations of an

elastic body are called natural vibrations and occur at a

frequency called the natural frequency. Natural vibrations are

different from forced vibrations which happen at frequency of

applied force (forced frequency). If forced frequency is equal

to the natural frequency, the amplitude of vibration increases

manifolds. This phenomenon is known as resonance. Numbers

of methods are available for the design optimization of

structural system and these methods are based on

mathematical programming technique and optimally designed

using ANSYS software.

II. LITERATURE REVIEW

(1) yeshwant Rao and praveen kumar B.S was find an various

tests, In vibration test, 2748Hz above will be subjected to

failure. In tensile test, the load of 6118.30kgs is breaks and it is

maximum tensile strength of connecting rod. In compression

test, 3615.91kgs is break and it is maximum point of

connecting rod. (2) Swapnil And Patil was analysis the

Connecting rod undergoes noise and vibration frequently. The

maximum von-misses stress generated is 37.618Mpa and the

maximum deformation generated is 0.0047524 mm. (3) G.

Sailaja, S. Irfan Sadaq, Shaik Vaseem Yunus was changed the

material to analysis the static and modal is carried out to

International Journal of Pure and Applied MathematicsVolume 119 No. 12 2018, 14037-14043ISSN: 1314-3395 (on-line version)url: http://www.ijpam.euSpecial Issue ijpam.eu

14037

determine the dynamic behavior of connecting rod by

considering deformation, strain and stresses when made with

Beryllium alloy using Analysis software. (4) Dr. N. A.

Wankhade, Suchita Ingale was to evaluate the approximate

values of bending stress acting on different material such as Al

7075, Al6061 and High strength carbon fiber which are used to

compare with the conventional material employed which is

steel. The connecting rod of high strength carbon fiber suffers

lesser in context of bending due to inertia and thus can be best

suited for connecting rod of diesel engine. (5) Satish Wable1,

Dattatray S.Galhe2. The Aluminum MMC connecting rod

shows less amount of stresses (ie.41%) than existing carbon

steel (16MnCr5) connecting rod. It is also found that the

Aluminum MMC connecting rod is light in weight (ie.23%)

than existing carbon steel (16MnCr5) connecting rod

approximately.

III. PROBLEM IDENTIFICATION

In modern automotive internal combustion engines, the

connecting rods are most usually made of steel for production

engines, but can be made of T6-2024 and T651-7075

aluminum alloys (for lightness and the ability to absorb high

impact at the expense of durability) or titanium (for a

combination of lightness with strength, at higher cost) for

high-performance engines, or of cast iron for applications such

as motor scooters. They are not rigidly fixed at right (for

endothermic engine) in steel, the left connecting rod (for

endothermic engine) has the modular head and the foot

equipped with a bushing, the central rod has the oil drip rod

equipped with pats either end, so that the angle between the

connecting rod and the piston can change as the rod moves up

and down and rotates around the crankshaft. Connecting rods,

especially in racing engines, may be called "billet" rods, if

they are machined out of a solid billet of metal, rather than

being cast or forged. Stress and failure of the connecting rod is

under tremendous stress from the reciprocating load

represented by the piston, actually Aluminum connecting rod

for 4-stroke engine, fatigue breakage and subsequent impact

with the crankshaft stretching and being compressed with

every rotation, and the load increases as the square of the

engine speed increase. Failure of a connecting rod, usually

called throwing a rod, is one of the most common causes of

catastrophic engine failure in cars, frequently putting the

broken rod through the side of the crankcase and thereby

rendering the engine irreparable; it can result from fatigue

near a physical defect in the rod.

IV. THEORETICAL DESIGN

Fig 1

V. CALCULATION

Pressure calculation for connecting rod

Engine type 4 stroke air cooled

Bore * stroke = 57 * 58.6 mm

Displacement = 149.5 cc

Maximum power = 13.8bhp@8500rpm

Compression ratio = 9.35:1

Density of petrol (C8H18) = 737.22kg/m3= 737.22E-9 kg/mm

3

Auto ignition temp = 2800 c

Mass = density * volume

= 737.22e9*149.5e

= 0.110214kg

Where, P = Pressure, Mpa

V = Volume

M = Mass, kg

Rspecific = Specific gas constant

T = Temperature, K

Rspecific = R/M

Rspecific = 8.3143/0.114228

Rspecific = 72.76 Nm/kg K

P = m Rspecific. T/V

P = (0.110214*72.757*553)/149.5= 29.67 Mpa

Calculation of analysis is done for maximum pressure of 30

Mpa and 15 Mpa

Design calculation for the connecting rod in general from

standards,

1) Thickness of the flange & web of the section = t

2) Width of the section, B = 4t

3) Height of the section, H = 5t

4) Area of the section, A = 11t^2

5) Moment of inertia about x axis, Ixx = 34.91t

6) Moment of inertia about y-axis, Iyy = 10.91t

International Journal of Pure and Applied Mathematics Special Issue

14038

7) Therefore Ixx/Iyy = 3.2 (safe because it lies between

3 to 3.5)

8) Length of the connecting rod (L)= 2 times stroke L =

117.2 mm

Total force acting F = Fp – FI

Where

Fp=force acting on the piston

FI=force of inertia

Fp=(2) * gas pressure

Fp = 39473.1543 N

FI = mw2r( )

M = mass of the reciprocating parts

Weight = 1.6 * 9.81 = 15.696 N

r = crank radius π

r = stroke of piston / 2

Also, = crank angle from dead centre

= 0 considering connecting rod is at TDC position

n = length of connecting rod / crank radius

g = acceleration due to gravity, 9.81 m/s2

v = crank velocity m/s

v = r w = 29.3e-3

* 890.1179 = 26.08 m/sec

On substituting these,

FI = 9285.5481

Thus,

F = 39473.1543 – 9285.5481 F = 30187.6062N

Now according to Rankine’s – Gordon formula,

F =

Let,

A = Cross section area of connecting rod,

L = Length of the connecting rod

Fc = compressive yield stress,

F = Buckling load

Ixx & Iyy = Radius of gyration of section about the x

For magnesium alloy:

Fc = 160Mpa

30187.6 =

t = 4.08mm

Width B = 4t = 4*4.08 = 16.32mm

Height H =5t=20.40mm

At the small end (H1) = 0.85*20.40=17.34mm

At the big end (H2) = 1.2H=1.2*20.40=24.48mm

Design of small end :

Load on piston pin (Fp) = projected area * bearing

pressure = dp lp * Pbp

39473.154 = dp * 1.5 dp * 10

dp = 51.29mm

lp = 76.5mm

outer diameter of small end = dp+2tb+2tm

= 51.29 + (2*2) + (2*5)

= 65.29mm

Design of big end :

Fb = dc lc * Pbc = dc *1.25 dc*7.5

39473.154 = 1.25 * 7.5 * dc2

dc = 64.88mm

VI. ANALYSIS

A. Model of the Connecting Rod is Shown Below

Fig-2 model of connecting rod

B. Fine Mesh Model is Shown Below

Fig-3 Fine Mesh Model

C.Analysis of Connecting Rod of aluminium alloy.

1.Equivalent Stress Analysis.


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Fig-4 Equivalent Stress Analysis

2.Maximum Shear Stress Analysis

Fig-5 Maximum Shear Stress Analysis

3. Maximum Principal Stress Analysis

Fig-6 Maximum Principal Stress Analysis

4. Total Deformation Analysis

Fig-20 Total Deformation Analysis

D.Analysis of Connecting Rod of titanium alloy

1.Equivalent Stress Analysis



Fig-8 Maximum Shear Stress Analysis



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E.Analysis of Connecting Rod of copper Alloy

1.Equivalent Stress Analysis



Fig-12 maximum shear stress Analysis






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VII. RESULT AND DISCUSSION

Table -1: Static structural Analysis of connecting rod with

aluminium inserts using ANSYS.

Parameters Minimum Maximum

Equivalent (Von-

Mises) Stress

(MPa)

0.00033377 14.8

Maximum Shear

Stress(MPa)

0.00018803 7.794

Maximum

Principal

Stress(MPa)

-2.7465 6.6766

Total

Deformation(mm)

0 0.022045


titanium inserts using ANSYS.


Equivalent (Von-

Mises)

Stress(MPa)

0.00038835 14.683

Maximum Shear

Stress(MPa)

0.00022287 7.7445

Maximum

Principal

Stress(MPa)

-2.9564 6.7424

Total

Deformation(mm)

0 0.016288


copper inserts using ANSYS.


Equivalent (Von-

Mises)

Stress(MPa)

0.00035527 14.761

Maximum Shear

Stress(MPa)

0.0001994 7.7776

Maximum

Principal

Stress(MPa)

-2.8169 6.6979

Total

Deformation(mm)

0 0.014224

VIII. CONCLUSION

From the above analysis we can conclude that

stresses of all the materials are almost comparable

and also in safe limit

The stresses induced in the small end of the

connecting rod are greater than the stresses induced

at the big end

Solid modelling of connecting rod was made in

fusion 360 according to production drawing

specification and analysis under theeffect of tensile

and compressive loads in terms of pressure is done in

ANSYS Workbench

Comparison is also made between the three materials

tensile stresses and al5083 alloy found least stresses.

IX. REFERENCES

1. yeshwant Rao and praveen kumar B.S “vibration

analysis of two wheeler connecting rod” Volume 3

Issue 6, June 2014.

2. P.Swapnil. J. Patil, Nihal Mulla, Swapnil Yadav,

Niraj Sawant, Sagar Pote” Design and Analysis of

Connecting Rod using Finite Element Analysis” Vol.

4, Special Issue 1, January 2017.

3. G. Sailaja, S. Irfan Sadaq, Shaik Vaseem Yunus,

“Dynamic Analysis of a Connecting Rod Using

FEA,” in Magnetism, ISSN (Print) : 2321-5747,

Volume-5, Issue-5, 2017.

4. Dr. N. A. Wankhade, Suchita Ingale, “Review on

Design and Analysis of Connecting Rod Using

Different Material”, Volume 7 Issue No.5, may 2017.

5. Satish Wable, Dattatray S.Galhe, “ANALYSIS OF

STRESSES INDUCED IN CONNECTING ROD OF

TWO WHEELER ENGINE,” Vol-2 Issue-3 2016

IJARIIE-ISSN (O)-2395-4396.

6. R A Savanoor, Abhishek Patil, Rakesh Patil and

Amit Rodagi, “FINITE ELEMENT ANALYSIS OF

IC ENGINE CONNECTING ROD BY ANSYS,”

ISSN 2278 – 0149, Vol. 3, No. 3, July 2014.

7. AbhinavGautam, K Priya Ajit, “Static Stress

Analysis of Connecting Rod Using Finite Element

Approach”, e-ISSN: 2278-1684,p-ISSN: 2320-334X,

Volume 10, Issue 1 (Nov. - Dec. 2013), PP 47-51.


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static analysis of connecting rod in a single …static analysis of connecting rod in a single...

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