FAILURE ANALYSIS OF IC ENGINE VALVES BY USING FEA

International Journal of Research and Innovation (IJRI)
International Journal of Research and Innovation (IJRI)
1401-1402
FAILURE ANALYSIS OF IC ENGINE VALVES BY USING FEA
K.Venkata Narayana 1 , K.koteswara Rao 2 ,Y Dhana Shekar 3
1 Research Scholar,Department Of Thermal Engineering, Kits, Peddapuram(M) Tirupathi Village, Divili 533-433,Eg Dt,AP, India.
2 Associate Professor,Department Of Thermal Engineering, Kits, Peddapuram(M) Tirupathi Village, Divili 533-433,Eg Dt,AP, India.
3 Assistant Professor , Department Of Thermal Engineering, Kits, Peddapuram(M) Tirupathi Village, Divili 533-433,Eg Dt,AP, India.
Abstract
Intake and exhaust valves are very important engine components that are used to control the flow of intake and exhaust
gases in internal combustion engines. They are used to seal the working space inside the cylinder against the manifolds;
and are opened and closed by means of what is known as the valve train mechanism.. These valves are loaded by spring
forces and subjected to thermal loading due to high temperature and pressure inside the cylinder.
The present study is forced on different failure modes of internal combustion engine valves.
Failures due to fatigue, high temperature effects, and failures due to impact load that depends on load and time.
For the study of fatigue life, a combined s-n (max. Stress v/s number of cycles) curve is prepared. Such a curve helps in
comparing the fatigue failure for different materials at different high temperatures and may also assist the researchers
in developing the valve materials with a prolonged life.
For achieving above sad goals couple –field, fatigue and transient analysis will be done on valves to determine structural
and thermal behavior in working condition.
Graphs will be generated for the same for easy understanding.
Keywords: Failure, internal combustion engine valves, high temperature, fatigue, wear
*Corresponding Author:
Kancharla Venkata Narayana,
Research Scholar,Department Of Thermal Engineering,
Kits, Peddapuram(M) Tirupathi Village, Divili 533-433,
Eg Dt,AP, India.
Published: January 22, 2015
Review Type: peer reviewed
Volume: II, Issue : I
Citation: Kancharla Venkata Narayana,FAILURE ANALYSIS
OF IC ENGINE VALVES BY USING FEA
Problem Discription
This project deals with “transient structural, transient
thermal analysis, fatigue and couple field
analysis (combination of transient structural and
Transient thermal) “on diesel engine valve at the
steady state condition. By applying thermal loads
by varying time. Also we are doing manufacturing
processes involved in the manufacturing of valve
Methodology
There are Different methodologies used by researchers
to obtain a good design and economic performance
of the valves by considering different valves
failure criteria. Different types of failure and their
causes are discussed in the following articles.
Failure due to fatigue:
The word fatigue is derived from the Latin fatigue
which means “to tire”. In engineering terminology
fatigue is a progressive structural damage of materials
under cyclic loads. Important categories of
fatigue include: Mechanical fatigue due to fluctuating
stresses Creep fatigue due to cyclic loads at
high temperatures; Thermal fatigue due to cyclic
changes in material’s
Temperature:
Thermo-mechanical fatigue due to a combination of
mechanical and thermal fatigue; corrosion fatigue
due to cyclic loads applied on corroded materials,
Fretting fatigue due to cyclic stresses together with
the oscillation motion and frictional sliding between
surfaces, etc.. Fatigue failure occurs at stresses that
are well below the yield point of the material.
I.C. Engine valves are subjected to repeated cyclic
loading due to valve train dynamics. Repeated loading
results in materials failing well below the yield
strength. When the material is subjected to fatigue,
one or more tiny cracks usually start developing in
the material, and these grow until complete failure
occurs. There are different types of fatigue mecha-
32

International Journal of Research and Innovation (IJRI)
nisms: thermal fatigue, high-cycle fatigue, low-cycle
fatigue, surface fatigue, bending fatigue, corrosion
fatigue, torsional fatigue, and fretting fatigue. In
valves, some of the more common failures are due
to thermal fatigue, corrosion fatigue, and low and
high-cycle fatigue.
What is a Valve Train?
• It is the set of components in a 4-stroke engine,
responsible for smooth functioning of the inlet and
exhaust valve
• It makes the valve to open and close as per the
timing required for the correct functioning of the engine
• The performance of the engine is severely depends
proper functioning of valve train. Any malfunctioning
in the valve train system could even lead to severe
damage to the engine
When it comes to fatigue, the S–N curves are often
used to represent fatigue behavior. Because fatigue
testing is time and energy consuming, predictive
methods are often used.
In many industries, the number of stress cycles for
lifetime services are above 107 cycles, The fatigue
fracture is basically observed under low cycle fatigue,
normally less than 105 cycles. The fatigue life
varies usually from 105 cycles to 107 cycles.
Researchers have come up with a number of results
for fatigue testing, one of them being discussed in
this paper for material X45CrSi93 stainless steel for
engine valves.
Transient structural and thermal analysis will be
conducted to determine structural and thermal defects
individually, coupled field and fatigue analysis
will be conducted to determine stress, deflection,
strain, life, fatigue sensitivity and damage/error in
combination both conditions at 5000 cycles as a
single cycle.
Fatigue cycles 1e 7 *5000 cycles as a single cycle.
Introduction To Ic Engine Valve
Valves Train Components for Internal Combustions
Engines, which include
1. Inlet and Exhaust Valves
2. Valve Guides
3. Tappets
4. Camshafts
What does an engine do?
• It generates the power required for moving the
vehicle or any other specific purpose.
• It converts the energy contained in fuel to useful
mechanical energy, by burning the fuel inside a
combustion chamber.
• An engine contains number of parts like Valves
and other Valve train components, Piston, camshaft,
Connecting rod, Cylinder block, Cylinder head
etc., from which REVL supplying some of the
valve train components to engine manufacturers
About Valves:
Engine Valve is one of the main parts which
are used in all IC Engines. Each cylinder in the engine
has one inlet and one exhaust valve. Now a
days engine are designed with multi valves viz., two
inlet and one exhaust or Two inlet and Two exhaust
valves which prevents air pollution and improves
engine efficiency.
Function of Inlet Valve:
The inlet which operates by the action of Tappet
movement, allows air and fuel mixture into the cylinder.
Function of Exhaust valve: The exhaust valve allows
burnt gases to escape from the cylinder to atmosphere.
Valve Efficiency:
Depends on the following characteristics like Hardness,
Face roundness and sliding properties capable
to withstand high temperature etc.
As compared to inlet, exhaust valve operates at high
temperature as exhaust gases (around 800 Deg C)
escape through it. As it resulting in early ways and
gets corrosion, austenitic steel is used for manufacture
of exhaust valve and martens tic steel is used
for manufacture of inlet valve.
The manufacturing process involves upset and forging,
heat treatment and machining (turning and
grinding) and special processes like TIG welding,
Projection Welding, PTA Welding, Friction Welding,
Induction Hardening and Nitriding.
33

International Journal of Research and Innovation (IJRI)
VALVE DIMENSIONS:
DESIGN CALCULATIONS OF EXHAUST VALVE
Introduction
Because of exposure to hot exhaust gases
and its effects on engine performance and volumetric
efficiency, the exhaust valve of an internal combustion
engine is one of the most critical parts. The
design of exhaust valves depends on many parameters,
Such as fluid dynamics of the exhaust gas, fatigue
strength of the valve material, oxi- dation characteristics
of the valve material, exhaust gas behavior of
the material at high temperature, the configuration
of the cylinder head, the coolant flow, the shape of
the exhaust port, etc. .
Design of outlet valve
The most significant factor in the performance of
an exhaust valve is its operating temperature. The
importance of temperature can best be appreciated
by its effect on the physical properties of the valve
steel. The exhaust valve of an internal combustion
engine operates under severe conditions of thermal,
fatigue, and mechanical stresses. Large temperature
gradients in the valve body are responsible
for thermal stresses. Knowledge of the temperature
field in different parts of an internal combustion engine
is important in order to ascertain the points of
highest thermal stress . A designer is always interested
in obtaining an optimum condition so that the
engine parts are not subjected to excessive stresses
due to gas pressure (mechanical loading) and thermal
loading. Meanwhile, the engine should not lose
a large amount of heat through the parts.
Description of the physical system
The geometry of the exhaust valve is shown in figure
1. The exhaust valve sits on the cylinder head
of a combustion chamber. The engine coolant liquid
passes around the cylinder liner and the water passages
in the cylinder head. The valve pops up and
down to let the exhaust gases leave the combustion
chamber. The up-and-down
34

International Journal of Research and Innovation (IJRI)
Values of the boundary conditions used in the
analysis
The values of the boundary conditions used for the
analysis are summarized in Table 1. The analysis
was performed under the worst thermal loading
condition of rated power. The engine specification
and operating condition are summarized in Table 2.
An analysis procedure using finite-element modeling
techniques is developed to analyze of the exhaust
valve thermal behavior.
The analysis consists of:
1. Construction of a suitable finite-element model
2. Selection of material properties
3. Engine specifications and operating conditions
4. Application of the thermal boundary conditions
5. Solution of the thermal finite-element model to
obtain the transient temperature distribution
6. Solution of the structural finite-element model to
obtain the stresses resulting from the imposed temperature.
Motion of the valve takes place with the help of a
rocker lever which is connected to the push rod.
The push rod rests over cams on the camshaft. The
valve is spring loaded. The spring keeps the valve
connected to the camshaft during its motion.
After the expansion process, the exhaust gases, at
high temperature, are purged through the exhaust
valve and as a result the temperature of the exhaust
valve increases. In order to avoid any damage to the
exhaust valve due to this high temperature, heat
must be continuously taken away from the valve.
This is achieved when the valve is in contact with
its seat. As the exhaust valves touch its seat, a significant
drop in exhaust valve temperature occurs.
Numerical Approach And Procedure
Assignment of the Boundary Conditions:-
When the valve is in contact with the
seat, the valve head is subjected to hot gases, with
gas temperature Tg(h) and heat transfer coefficient
hg(h). (h) is the crank The figures shows the fig.1 .
Diagram of measured gas temperature in the cylinder
Fig. Diagram of measured gas pressure in the
cylinder
Finite-Element Modeling
The thermal stress analysis is performed using
the parametric design language of the ansys software
(apdl). By using this method for the simulation,
the boundary conditions and the geometry can
be changed in the model. Therefore, the model can
be used at all operating conditions. For modeling of
the exhaust valve, the axisymmetric modeling capability
of the ansys software is used. An axisymmetric
solid is generated by revolving a plane about an
axis in the plane that is called the symmetry axis.
The geometric and material properties are symmetric
about the symmetry axis. In addition, it is considered
that the thermal loadings are symmetric.
Material Properties
The physical and mechanical properties of the
exhaust valve material are shown in Table 4. T is
temperature, Su is ultimate strength, Sy is yield
strength, n is Poisson’s ratio, a is the thermal expansion
coefficient, K is the thermal conductive coefficient,
C is specific heat, and q is density. The
material properties are selected for austenitic steel
whose UNS specification is S63008.
Thermal Analysis
Boundary conditions as explained above are
applied to the model. Transient thermal analysis is
initiated with initial temperature of 25 C. For thermal
analysis a loop is used, each loop representing
a cycle of engine operation. In each cycle, the
crankshaft rotates twice and the camshaft rotates
once. In each 242 of camshaft rotation the exhaust
valve is closed, and in the remaining 118 the valve
is open. Therefore, each cycle is divided into two
parts (closed and open periods). The time
35

International Journal of Research and Innovation (IJRI)
Structural Analysis
Thermal Analysis
36

International Journal of Research and Innovation (IJRI)
Fatigue Analysis
Each loading history value refers to 5000*1e007
cycles
Material & valve manufacturing process
Valve process flow with head to pin friction welding
1. One halve of the bar is upsetted and then forged
2 .Now the forged head is welded to another bar by
friction welding.
3. Deburring is done to remove the flash generated
in friction welding
4. .The valves obtained are straightened and given
as input to rough
Centreless grinding operation.
Valve processing at Friction welding :
37

International Journal of Research and Innovation (IJRI)
The operations which are eliminated in “Head to
pin” process are highlighted and indicated by an
arrow.
Benefits
Material Saving:
1.45665 - Rs. 2.59 / Valve
2.40574 – Rs. 1.46 / Valve
3.40579 – Rs. 1.40 / Valve
Grinding Cost Saving :
1.45665 - Rs. 0.99 / Valve
2.40574 – Rs. 0.65 / Valve
3.40579 – Rs. 0.65 / Valve
Totally four operations eliminated for these part
nos.
Total savings per annum – Rs.20.0 lakhs
In-direct benefit: This becomes a Poke-Yoke to avoid
reverse material forging which is one of the critical
customer complaints.
Lead time reduced by 2 days
Conclusion
Valve Process Flow chart with Head to Pin Friction
welding
In this teases “FAILURE ANALYSIS OF IC ENGINE
VALVES BY USING FEA” is done and manufacturing
segment is also presented for the valves.
Initially litrecher survey is done to understand the
process.
Model is developed for further study in FEM.
Static analysis is done on valve, valve with seat and
fin segments by varying two materials.
Study-state thermal analysis is done on valve, valve
with seat and fin segments by varying two materials.
Transient structural analysis is done on valve, valve
with seat and fin segments by varying two materials
@5000 cycles.
Transient thermal analysis is done on valve, valve
with seat and fin segments by varying two materials
@5000 cycles.
Coupled field analysis (combined analysis of static
and thermal) is done on valve, valve with seat and
fin segments by varying two materials.
Fatigue analysis is done on valve, valve with seat
and fin segments by varying two materials.
Result for above analysis is presented in tables.
Manufacturing process of valve is briefly explained.
As per the analytical results valve with meg alloy fin
is the right choice for maximum life.
References
1.Failure analysis of internal combustion engine valves: a review
2.Naresh kr. Raghuwanshi1, ajay pandey2, r. K. Mandloi3 international
journal of innovative research in science, engineering
and technology vol. 1, Issue 2, december 2012
38

International Journal of Research and Innovation (IJRI)
3.Combating automotive engine valve recession by roger lewis
and rob s.Dwyer-joyce university of sheffield dept. Of mechanical
engineering sheffield, united kingdom engine valve recession
4.Investigation of exhaust valve failure in heavy – duty diesel engine
nurten vardar1, ahmet ekerim2 gazi university journal of
science gu j sci 23(4):493-499 (2010)
5.Modelling of the heat loads of the engine valves and the accuracy
of calculations p. Gustof, a. Hornik* faculty of transport, department
of vehicle service, silesian university of technology, ul.
Krasińskiego 8, 40-019 katowice, poland received 03.04.2007;
Published in revised form 01.08.2007 Journal of achievements
in materials and manufacturing engineering
6.Modelling and analysis of radial thermal stresses and temperature
field in diesel engine valves with and without air cavity subodh
kumar sharma1*, p. K. Saini2, n. K. Samria3
20.C.G. Scott, a.T. Riga and h. Hong. The erosion-corrosion of
nickel-base diesel engine exhaust valves. Wear 181-183 (1995)
485-494.
21.Zhao yun-cai and yan hang-zhi, experimental study on wear
failure course of gas-valve/valve-seat in engine. J. Cent. South
university. Technology 12 (2005) 243-246.
22.P. Forsberg, p. Hollman, and s. Jacobson, wear mechanism
study of exhaust valve system in modern heavy duty combustion
engines. Wear 271 (2011) 2477– 2484
23.Keyoung jin chun, jae hak kim, and jae soo hong, a study of
exhaust valve and seat insert wear depending on cycle numbers.
Wear 263 (2007) 1147– 1157
Authors
7.Failure analysis of an intake valve in a gasoline engine m.
Azadi1*, m. Roozban2, a. Mafi3
The journal of engine research
Accepted: 20 march2013
8.Failure analysis of exhaust valve spring of c.I.Engine patel
sujal v.1, Pawar shrikant g.2 1 Research scholar, department
of automobile engineering, rit sakharale 415414, sangli, maharashtra,
india), 2 associate professor, department of automobile
engineering, rit sakharale 415414, sangli, maharashtra, india)
international journal of engineering research & technology (ijert)
vol. 2 Issue 3, march - 2013 issn: 2278-0181 1
9.Engine cylinder head thermal and structural stress analysis
ing. Radek tichánek, ing. Miroslav španiel, csc. Czech technical
university in prague technická 4, prague 6 cz-166 07, czech
republic
Kancharla Venkata Narayana
Research Scholar
(mtech in Thermal Engineering)
Kits, Peddapuram(M) Tirupathi Village,
Divili 533-433,
Eg Dt,Ap,India.
10.Computational visualization and simulation of diesel engines
valve lift performance using cfd 1semin, 1rosli abu bakar and
1abdul rahim ismail 1automotive focus group, faculty of mechanical
engineering, university malaysia pahang, locked bag
12, 25000 kuantan, pahang, malaysia american journal of applied
sciences 5 (5): 532-539, 2008 issn 1546-9239
11.M. I. Karamangil a. Avci and h. Bilal , investigation of the effect
of different carbon film hickness on the exhaust valve. Heat
mass transfer 44 (2008) 587–598
12.H. J. C. Voorwalda, r. C. Coisse, and m. O. H.Cioffi. Fatigue
strength of x45crsi93 stainless steel applied as internal combustion
engine valves. Procedia engineering 10 (2011) 1256–1261.
K.koteswara Rao.
Assistant professor
Kits, Peddapuram(M) Tirupathi Village,
Divili 533-433,
Eg Dt,Ap,India.
13.V.Kazymyrovych, very high cycle fatigue of engineering materials.
Karlstad university studies 2009:22. Issn 1403-8099, isbn
978-91-7063-246-4
14.Dowling, norman e.: Mechanical behavior of materials, engineering
methods for deformation, fracture and fatigue. Prenticehall.
15.D. J. Benac and r. A. Page, integrating design, maintenance,
and failure analysis to increase structural valve integrity. Asm
international 3 (2001) 31- 43
16.Y.B. Liu, y.D. Li, s.X. Li, z.G. Yang,s.M. Chen, w.J. Hui, and
y.Q. Weng , prediction of the s–n curves of high-strength steels in
the very high cycle fatigue regim. International journal of fatigue
32 (2010) 1351–1357
Y Dhana Shekar,
Assistant Professor ,
Kits, Peddapuram(M) Tirupathi Village,
Divili 533-433,
Eg Dt,AP, India
17.Oh geon kwon and moon sik han, failure analysis of the exhaust
valve stem from a waukesha p9390 gsi gas engine. Engineering
failure analysis 11 (2004) 439-447
18.Z.W. Yu and x.L. Xu, failure analysis and metallurgical investigation
of diesel ngine exhaust valves. Engineering failure analysis
13 (2006) 673–682
19.Alan v. Levy, solid particle erosion and erosion-corrosion of
materials. Opyright1995 by asm international
39