The crankshaft is that part of an engine which translates reciprocating linear piston motion into rotation. To convert the reciprocating motion into rotation, the crankshaft has "crank" or "crankpins", additional bearing surfaces whose axis is offset from that of the crank, to which the "big ends" of the connecting rods from each cylinder attach. The aim of the project work is to optimize the geometry shape of 6-cylinder diesel engine crank shaft to reduce the failures and to reduce the weight. And also this project work will provide the brief explanation of manufacturing process. Initially literature survey and data collection will be done to understand methodology. Design calculations will be done to get parameters of object for drafting. 3D model will be prepared according to the obtained parameters. Analysis will be conducted on crank shaft to rectify failures by optimizing geometric shape. Also best material will be suggested by analyzing and comparing results with the variation of materials. Mold tool design will be done and assembly will be prepared according to that. Cnc program will be prepared for die set using cam

1. 108
International Journal of Research and Innovation (IJRI)
International Journal of Research and Innovation (IJRI)
GEOMETRIC OPTIMIZATION AND MANUFACTURING PROCESS OF SIX CYLINDER
DIESEL ENGINE CRANK SHAFT USED IN AUTOMOBILE USING FEA
Karnati Sreedhar 1
,Gandhi Perumallapalli2
, D.sreeramprasad 3
1 Research Scholar, Department Of Mechanical Engineering, Sri Venkateswara Engineering College, Amaravadi Nagar, Suryapet,India
2 Assistant professor , Department Of Mechanical Engineering, Sri Venkateswara Engineering College, Amaravadi Nagar, Suryapet,India
3 Associate Professor , Department Of Mechanical Engineering, Sri Venkateswara Engineering College, Amaravadi Nagar, Suryapet,India
*Corresponding Author:
Karnati Sreedhar,
Research Scholar, Department Of Mechanical Engineering,
Sri Venkateswara Engineering College,
Amaravadi Nagar, Suryapet,India
Published: May 20, 2015
Review Type: peer reviewed
Volume: II, Issue : II
Citation: Karnati Sreedhar, Research Scholar (2015)
GEOMETRIC OPTIMIZATION AND MANUFACTURING PROCESS
OF SIX CYLINDER DIESEL ENGINE CRANK SHAFT USED IN
AUTOMOBILE USING FEA
Problem Description
When observing 6 cylinder automobiles like busses
having frequent break downs due to engine failures.
Millage is also become one of the most important
thing in those days if we can reduce the mechanical
efficiency.
Commonly crank shafts are made with low carbon
steels and casting along with milling is used to the
produce object.It causes low production rate and
high cost.
Methodology
This is an attempt to reduce weight, improve life
time and to improve production rate by implement-
ing geometric optimization we can reduce failure
and by introducing new materials we can reduce
weight as well as we switch manufacturing process.
By implementing metal injection system we can im-
prove production rate.
Introduction
The crankshaft, sometimes casually abbreviated
to crank, is the part of an engine which translates
reciprocating linear piston motion into rotation. To
convert the reciprocating motion into rotation, the
crankshaft has "crank throws" or "crankpins", ad-
ditional bearing surfaces whose axis is offset from
that of the crank, to which the "big ends" of the con-
necting rods from each cylinder attach.
It typically connects to a flywheel, to reduce the pul-
sation characteristic of the four-stroke cycle, and
sometimes a torsional or vibrational damper at the
opposite end, to reduce the torsion vibrations often
caused along the length of the crankshaft by the
cylinders farthest from the output end acting on the
torsional elasticity of the metal.
Stress on crankshafts
The shaft is subjected to various forces but gener-
ally needs to be analysed in two positions. Firstly,
failure may occur at the position of maximum bend-
ing; this may be at the centre of the crank or at
either end. In such a condition the failure is due to
bending and the pressure in the cylinder is maxi-
mal. Second, the crank may fail due to twisting, so
the conrod needs to be checked for shear at the po-
sition of maximal twisting. The pressure at this po-
sition is the maximal pressure, but only a fraction
of maximal pressure.
A crankshaft contains two or more centrally-located
coaxial cylindrical ("main") journals and one or more
offset cylindrical crankpin ("rod") journals. The two-
Abstract
The crankshaft is that part of an engine which translates reciprocating linear piston motion into rotation. To convert the
reciprocating motion into rotation, the crankshaft has "crank" or "crankpins", additional bearing surfaces whose axis is
offset from that of the crank, to which the "big ends" of the connecting rods from each cylinder attach.
The aim of the project work is to optimize the geometry shape of 6-cylinder diesel engine crank shaft to reduce the fail-
ures and to reduce the weight. And also this project work will provide the brief explanation of manufacturing process.
Initially literature survey and data collection will be done to understand methodology.
Design calculations will be done to get parameters of object for drafting.
3D model will be prepared according to the obtained parameters.
Analysis will be conducted on crank shaft to rectify failures by optimizing geometric shape. Also best material will be
suggested by analyzing and comparing results with the variation of materials.
Mold tool design will be done and assembly will be prepared according to that.
Cnc program will be prepared for die set using cam
1401-1402

2. 109
International Journal of Research and Innovation (IJRI)
plane v8 crankshaft pictured in figure 1 has five
main journals and four rod journals, each spaced
90° from its neigbors.
The crankshaft main journals rotate in a set of sup-
porting bearings ("main bearings"), causing the off-
set rod journals to rotate in a circular path around
the main journal centers, the diameter of which is
twice the offset of the rod journals. The diameter
of that path is the engine "stroke": the distance
the piston moves up and down in its cylinder. The
big ends of the connecting rods ("conrods") contain
bearings ("rod bearings") which ride on the offset
rod journals.
Crankshaft materials
The steel alloys typically used in high strength
crankshafts have been selected for what each de-
signer perceives as the most desirable combination
of properties. Figure 6 shows the nominal chemis-
tries of the crankshaft alloys discussed here.
Medium-carbon steel alloys are composed of pre-
dominantly the element iron, and contain a small
percentage of carbon (0.25% To 0.45%, Described
as ‘25 to 45 points’ of carbon), along with combina-
tions of several alloying elements, the mix of which
has been carefully designed in order to produce
specific qualities in the target alloy, including hard-
enability, nitridability, surface and core hardness,
ultimate tensile strength, yield strength, endurance
limit (fatigue strength), ductility, impact resistance,
corrosion resistance, and temper-embrittlement
resistance. The alloying elements typically used in
these carbon steels are manganese, chromium, mo-
lybdenum, nickel, silicon, cobalt, vanadium, and
sometimes aluminium and titanium. Each of those
elements adds specific properties in a given mate-
rial. The carbon content is the main determinant of
the ultimate strength and hardness to which such
an alloy can be heat treated.
Nanomaterials
The role of nanomaterials in modern technologies
is becoming increasingly significant because of the
feasibility and ease of adding new functions to the
existing commercial products, apart form products
made completely from nanomaterials through the
bulk, which is relatively difficult. Nanomaterials are
usually characterized by a feature size of less than
100 nm at least in one dimension.
Recently in april 2010, us epa has announced a new
working definition of nanomaterials as “an ingredi-
ent that contains particles that have been intention-
ally produced to have at least one dimension that
measures between approximately 1 and 100 na-
nometers” in order to facilitate the implementation
of regulations on use of nanomaterials in commer-
cial products.
Introduction to cad
Throughout the history of our industrial society,
many inventions have been patented and
Whole new technologies have evolved. Perhaps the
single development that has impacted
Manufacturing more quickly and significantly than
any previous technology is the digital computer.
Introduction to pro/engineer
Pro/engineer is the industry’s standard 3d mechan-
ical design suit. It is the world’s leading cad/cam /
cae software, gives a broad range of integrated so-
lutions to cover all aspects of product design and
manufacturing.
Advantages of pro/engineer
1.It is much faster and more accurate. Once a de-
sign is completed. 2D and 3d views are readily ob-
tainable.
2.The ability to incorporate changes in the design
process is possible.
3.It provides a very accurate representation of mod-
el specifying all other dimensions hidden geometry
etc.
4.It provides a greater flexibility for change. For ex-
ample if we like to change the dimensions of our
model, all the related dimensions in design assem-
bly, manufacturing etc. Will automatically change.
5.It provides clear 3d models, which are easy to
visualize and understand.
6.Pro/e provides easy assembly of the individual
parts or models created it also decreases the time
required for the assembly to a large extent.
Design of multi cylinder engine crank shaft (die-
sel engine) specifications

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International Journal of Research and Innovation (IJRI)
Pressure calculations
Engine type: air cooled 4-stroke
(Agco sisu power 66cta bus)
Number of cylinders =6
Bore diameter (d) = 108 mm
Stroke length (l) = 120mm
Maximum combustion pressure=10.466N/mm2
Displacement =6600cc
Compression ratio =23:1
Density of diesel = 874.6081Kg/m3
at 15°c
T =288.855K
Mass = density ×volume
= 0.0000008746081×6600000
= 5.77Kg
Molecular weight for diesel is 200 g/mole
Pv = mrt
We know that force on the piston i, e: gas load
In order to find the thrust in connecting rod we
should find out angle of inclination of connecting
rod with line of stroke (i,e: angle ) (lies between 30°
to 40°)
Assume that the distance (b) between the bearings 1
and 2 is equal to twice the piston diameter (d).
B = 2d = 2 × 108 =216mm
Due to this piston gas load (fp
) acting horizontally,
there will be two horizontal reactions h1and h2 at
bearings 1 and 2 respectively, such that
B1 = b2= 108mm
Assume that the length of the main bearings to be
equal, i.E.,
C1 = c2 = c / 2.
We know that due to the weight of the flywheel
acting downwards, there will be two vertical reac-
tions v2 and v3 at bearings 2 and 3 respectively,
such that
Model of crank shaft
The above image shows total sections
2D drafting crankshaft
Powder metallurgy
Powder metallurgy is a forming and fabrication
technique consisting of three major processing stag-
es. First, the primary material is physically pow-
dered, divided into many small individual particles.
Next, the powder is injected into a mold or passed
through a die to produce a weakly cohesive struc-
ture (via cold welding) very near the dimensions of
the object ultimately to be manufactured. Pressures
of 10-50 tons per square inch are commonly used.
Also, to attain the same compression ratio across
more complex pieces, it is often necessary to use
lower punches as well as an upper punch. Finally,
the end part is formed by applying pressure, high
temperature, long setting times (during which self-

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International Journal of Research and Innovation (IJRI)
welding occurs), or any combination thereof.
Cad/cam in die design
In the die casting scenario the advent of digital com-
puters has facilitated the improvement of productiv-
ity and elimination of costly rework. Here before
the physical realization of the die, the design can be
redefined and the parameters can be decided which
would yield good results. Variety of feed systems
and combination of ideas can be selected. This is
an analytic approach to estimate the validity of the
design. Thus it gives enormous confidence to the
designer even before the tool is manufactured.
Core & cavity design with pro/engineer
Core cavity preparation
Create parting surface
Create work piece
The above image shows cavity 1
The above image shows total die assembly
The above image shows exploded view of complete die
Introduction to manufacturing
The manufacturing of various products is done at
different scales ranging from humble domestic pro-
duction of say candlesticks to the manufacturing of
huge machines including ships, aeroplanes and so
forth. The word manufacturing technology is mainly
used for the latter range of the spectrum of manu-
facturing, and refers to the commercial industrial
production of goods for sale and consumption with
the help of gadgets and advanced machine tools.
Industrial production lines involve changing the
shape, form and/or composition of the initial prod-
ucts known as raw materials into products fit for
final use known as finished products.
Procedure of manufacturing
Cavity
Roughing
With workpiece

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International Journal of Research and Innovation (IJRI)
Cutting tool
Playpath
Vericut
Roughing program
%
G71
O0001
(Roughing.Ncl.1)
(04/30/15-12:13:46)
N0010t1m06
S1500m03
G01g43x-377.072Y-157.018Z2.F500.H01m08
Z-2.F150.
Introduction to fea
Finite element analysis (fea) was first developed in
1943 by r. Courant, who utilized the ritz method of
numerical analysis and minimization of variational
calculus to obtain approximate solutions to vibra-
tion systems. Shortly thereafter, a paper published
in 1956 by m. J. Turner, r. W. Clough, h. C. Mar-
tin, and l. J. Topp established a broader definition
of numerical analysis. The paper centered on the
"stiffness and deflection of complex structures".
By the early 70's, fea was limited to expensive main-
frame computers generally owned by the aeronaut-
ics, automotive, defense, and nuclear industries.
Since the rapid decline in the cost of computers and
the phenomenal increase in computing power, fea
has been developed to an incredible precision. Pre-
sent day supercomputers are now able to produce
accurate results for all kinds of parameters.
Fea consists of a computer model of a material or
design that is stressed and analyzed for specific re-
sults. It is used in new product design, and existing
product refinement. A company is able to verify a
proposed design will be able to perform to the cli-
ent's specifications prior to manufacturing or con-
struction. Modifying an existing product or struc-
ture is utilized to qualify the product or structure
for a new service condition.In case of structural fail-
ure, fea may be used to help determine the design
modifications to meet the new condition.
Introduction to ansys
Ansys is general-purpose finite element analysis
(fea) software package. Finite element analysis is
a numerical method of deconstructing a complex
system into very small pieces (of user-designated
size) called elements. The software implements
equations that govern the behaviour of these ele-
ments and solves them all; creating a comprehen-
sive explanation of how the system acts as a whole.
These results then can be presented in tabulated,
or graphical forms. This type of analysis is typically
used for the design and optimization of a system far
too complex to analyze by hand. Systems that may
fit into this category are too complex due to their
geometry, scale, or governing equations.
Material properties and boundary
Conditions
Material properties :carbon steel

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International Journal of Research and Innovation (IJRI)
Boundary conditions
Constrained at crankshaft both ends
Pressure on shaft
Structural analysis of crankshaft
Existing model
Material: carbon steel
The above image shows total deformation
The above image shows stress
The above image shows strain
Dynamic analysis of crankshaft
Existing model
The above image shows total deformation mode 1
The above image shows total deformation mode 2
Fatigue analysis of crankshaft existing model
The above image shows life

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International Journal of Research and Innovation (IJRI)
The above image shows safety factor
The above image shows biaxiality indication
Structural analysis of crankshaft
Existing model
Material: nano material
The above image shows total deformation
The above image shows stress
The above image shows strain
Dynamic analysis of crankshaft
Existing model
The above image shows total deformation mode 1

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International Journal of Research and Innovation (IJRI)
The above image shows total deformation mode 2
Fatigue analysis of crankshaft existing model
The above image shows life
The above image shows safety factor
Modified model
2D drafting
Structural analysis of crankshaft
Modified model
Material: carbon steel
The above image shows total deformation
The above image shows stress

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International Journal of Research and Innovation (IJRI)
The above image shows strain
Results and graphs
Structural analysis
The above image shows total deformation graph
The above image shows stress graph
The above image shows strain graph
Fatigue analysis
The above image shows safety factor
Results Table
STRUCTURAL ANALYSIS
Existing model Modified model
carbon
steel
Nano
material
carbon
steel
Nano
material
Total de-
formation
0.00679 0.012065 0.0059 0.0104887
Stress 12.626 12.348 10.955 10.711
Strain 5.9963e-5 0.000106 5.1513e-5 9.1435e-5
Dynamic analysis
Existing model Modified model
carbon
steel
Nano
material
carbon
steel
Nano
material
Total defor-
mation mode
1HZ
65.455 54.36 66.017 54.827
Total defor-
mation mode
2 HZ
67.961 56.441 68.569 56.946
Total defor-
mation mode
3 HZ
179.08 148.73 180.71 150.08
Total defor-
mation mode
4 HZ
187.09 155.38 188.54 156.58
Total defor-
mation mode
5 HZ
248.42 206.31 254.31 211.2
FATIGUE ANALYSIS
Existing model Modified model
carbon
steel
Nano
material
carbon
steel
Nano
material
LIFE 1e6 1e6 1e6 1e6
Damage 1000 1000 1000 1000
Safety
factor
3.416 3.4903 3.9344 4.0238
Biaxiality
indication
0.99856 0.99856 0.99907 0.99907
Alternat-
ing stress
25.252 24.697 21.909 21.422

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International Journal of Research and Innovation (IJRI)
Conclusion
This project works deals with “geometric optimiza-
tion and manufacturing process of six cylinder die-
sel engine crank shaft used in automobile using fea”
Initially literature survey and data collection was
done to understand methodology.
Crank shaft parameters are calculated using em-
pirical formals for 6 cylinder engine.
3D model is prepared according to the obtained
valve from calculation,
Static, fatigue and dynamic analysis is done on
crankshaft using low carbon steel (existing).Same
as been done using steel nano material and to find
out the failure locations and to evaluate results for
new material.
Geometric modifications are done on crank shaft
model to reduce stress concentration by implement-
ing stress reliving holes on web.
As per the static, fatigue and dynamic analysis re-
sults, existing model is up to the mark only. Im-
plementation of nano material will increase life by
2%, while appling stress reliving holes, life will be
increased by 17.8% And also weight can be reduced
by 22%due to low density for nano steel alloy. Also
material is removed from the crank web. So better
to use modified model with nano material.
In the next step manufacturing is described and for
the nano materials better to go with metal injection
process.
Mould parts are prepared and assembly, which con-
tains ejectors, retainers, spacer housing and pins.
Cnc codes are generated using cam in pro/engineer.
This project concludes that modified model with
nano material increases the life and also weight will
be reduced up to 35% which interns increases the
mechanical efficiency. Metal injection process is the
most efficient way to manufacture crankshaft with
nano material and also it increase the production
rate
References
1.Dynamic stress analysis of a multi cylinder two-stage compres-
sor crankshaft Research journal of engineering sciences
2.Design and analysis of crankshaft for single cylinder 4-stroke
deisel engine Crankshaft design and optimization- a review
National conference on recent trends in engineering & technology
3.Theoretical and experimental analysis of torsional and bend-
ing effect on four cylinders engine crankshafts by using finite
element approach International journal of engineering research
4.Fatigue strength and residual stress analysis of deep rolled
crankshafts International journal of engineering and technology
(ijet)
5.Finite element analysis of 4-cylinder diesel crankshaft
6.Crankshaft strength analysis using finite element method
International journal of engineering research
7.Concept and manufacture of a crankshaft production tool
8.Elastic multi body simulation of a multi-cylinder engine
The open mechanical engineering journal,
Authour
Karnati sreedhar
Research scholar, department of mechanical
engineering,sri venkateswara engineering college,
Amaravadi nagar, suryapet - 508213.Nalgonada
(dt), india.
Gandhi perumallapalli
Assistant professor in mechanical engineering
Sri venkateswara engineering college,
Amaravadi nagar, suryapet - 508213.Nalgonada
(dt),india.
D.Sreeramprasad
Associate professor in mechanical engineering
Sri venkateswara engineering college,
8 Years industrial, 18 years teaching+ years