review on internal combustion engine vibrations and

review on internal combustion engine vibrations and
International Journal of Engineering Sciences & Emerging Technologies, August 2012.
ISSN: 2231 – 6604
Volume 3, Issue 1, pp: 63-73 ©IJESET
T. Ramachandran*1, K. P. Padmanaban2
Assoc. Prof., PSNA College of Engineering & Technology, Dindigul, Tamilnadu, India.
[email protected]
Director, SBM College of Engineering & Technology, Dindigul, Tamilnadu, India,
[email protected]
Ride comfort, driving stability and drivability are vital factors in terms of vehicle performance and the customer
satisfaction. The power plant (IC engine) is the source for the vibration that reduces the vehicle performance
and it need to be controlled to some extent such that the vehicle performance will be improved. The IC engine is
made up of reciprocating and rotating parts and they produce unbalanced forces during their operation and
produce the vibratory output at the vehicle supporting members. The vibration reduction will be possible by
minimizing unbalanced forces and by providing the anti vibration mounts at the engine-vehicle interface. Many
researches were made to find the causes for the vibration and to reduce the vibrations at the engine supports.
But still there is a research gap on the vibration modeling and vibration isolation of the engine. In this work, an
attempt is made to represent the state-of-the- art for the engine vibrations and its isolations and to provide a
gate way for the future work on it. It reveals the various work carried out on the engine multibody modeling of
the IC engine components and different engine mountsand their orientations. The review is structured as engine
multibody modeling, engine vibrations and engine mounting areas and revealed the gaps and untouched parts
that requires further research.
KEYWORDS: Internal combustion(IC) engine, Unbalanced forces, Vibration, Engine mount,
The internal combustion (IC) engine is the concentrated mass in vehicle and if not properly designed
it will cause vibrations and transfer to the supporting structures ride comfort, driving stability and
drivability are important factors for the performance of a vehicle and are affected by the engine
vibrations. Because of the environmental considerations, as well as changes in consumer preferences
regarding vibration induced must be reduced. Vibration behavior of an IC engine depends on
unbalanced reciprocating and rotating parts, cyclic variation in gas pressure, shaking forces due to the
reciprocating parts and structural characteristics of the mounts. Engine vibrations are caused due to
the reciprocating and rotating masses of the engine. The variations of inertial forces are due to the
combustion and the compression differences of the piston cylinder arrangement during their
operation. The engine inertial forces leads to the unbalanced forces of the engine and they are quiet
varying with respect to speed, fuel supply and combustion characteristics of the fuel. To predict the
vibration output of an engine and to minimize the possible durability and consumer perceived quality
problems associated with engine vibration, a robust and accurate design and simulation model is
needed. To reduce the engine vibration proper mounting must be provided as dampers at the interface
of the engine and chassis.
The vibrations caused at the engine are two types they are torsional and longitudinal vibrations.
Engines always have some degree of torsional vibration during operation due to their reciprocating
International Journal of Engineering Sciences & Emerging Technologies, August 2012.
ISSN: 2231 – 6604
Volume 3, Issue 1, pp: 63-73 ©IJESET
nature. The rotation of crankshaft of an engine increases the cylinder pressure as the piston
approaches top dead centre (TDC) on the compression stroke. Ignition and combustion increases the
pressure just after TDC and the pressure starts to decrease when the piston moves down to bottom
dead centre (BDC). The pressure on the piston generates the tangential force that does useful work
and increases the rotational speed of the crankshaft during this combustion stroke, whereas the
compression stroke decreases the engine’s angular velocity. The changing rotational speed results in
the speed fluctuations of the crankshaft and the torsional vibrations at the crankshaft. The
reciprocating and rotating components of engine have subjected to variation in inertial motion and the
combustion pressure during the operation and the variation in the inertial motion of the parts during
the upward motion and variation in the combustion pressure during the downward motion produce the
unbalanced forces at the engine block and the unbalanced forces at the block are measured as
longitudinal vibrations in the three orthogonal direction. Both the vibrations can be reduced by
minimizing the unbalanced forces and by supporting the engine at proper mounts.
The engine mounts should have characteristics of high stiffness and high damping in the lowfrequency range and of low stiffness and low damping in the high-frequency range. Hydraulic mounts
do not perfectly satisfy such requirements. Although hydraulic mounts greatly increase damping at
low frequencies, they also degrade isolation performance at higher frequencies. Also hydraulic
mounts are not cost effective, they had complexity in design and low reliability. Though various types
of hydraulic mounts have been developed for the vehicle mount systems, it is still reported that the
rubber mounts show significant importance in ride comfort and reduced noise levels. Rubber mounts
can be designed for the necessary elastic stiffness rate characteristics in all directions for proper
vibration isolation and they are compact, cost-effective, and maintenance free. Also the rubber mounts
offer a trade-off between static deflection and vibration isolation. Rubber mounts have been
successfully used for vehicle engine mounts for many years.
Therefore a multi-physics approach needed to be used to address all these physical properties in a
single design model. To identify the various methods used and assumptions followed to find and
reduce the engine vibrations a survey were made on the Engine 1.Rigid body modeling 2. Vibrations
and 3. Mountings.
IC engine consists of different components such as engine block, engine head, piston, connecting rod,
crank shaft, flywheel and cam shaft, valves, manifolds, pulleys etc. Some of parts are identified by the
researchers and engine manufacturers as the vibration producing parts. The piston connecting rod,
crank shaft and engine block are the major components which produces unbalanced forces during the
operation. As they are interconnected together the forces are transferred to the engine block and hence
to the supporting structures. Many mathematical rigid body models were proposed by the researchers
using multibody modeling of the engine structure to calculate the unbalanced forces from the engine.
Sudhir Koul et. al [4], developed a mathematical model based on the structural dynamics that includes
frame, power train assembly, swing arm assembly and engine mounting system. The authors
developed two models with six degrees of freedom rigid body modeling of the flexible frame. In the
first model, it consists of finite element modeled stiffness matrix such that the nodes of the frame
connect the other sub-system. The other is the respective dynamic model of the frame and the swing
arm. The model was developed such that the mount stiffness, mount locations and mount orientations
were the design variables. The model was simulated for two different load models and the results
were optimized for the frame stiffness and for the minimum force transmitted to the frame. Hoffman
and Dowling [21] conducted an experiment on heavy duty in-line six-cylinder Diesel Engine to
measure all the three orthogonal vibration force components at the each of the three engine mounts
during standard impact-excitation. Modal identification tests on the quiescent-engine and during
engine operation. Deana. M. Winton and Dowling [22] conducted an experimental study to determine
the rigid body modal content of engine block vibration on a modern heavy-duty inline six-cylinder
Diesel engine. They used three engine mounts fitted with multi-axis force transducers and exploited
standard modal analysis to determine rigid body modal characteristics and engine mount forces
signatures of the engine vibration modes of engine block. Hoffman and Dowling [23] developed a
seven degree-of-freedom model for low frequency engine vibrations that utilizes two way coupling
International Journal of Engineering Sciences & Emerging Technologies, August 2012.
ISSN: 2231 – 6604
Volume 3, Issue 1, pp: 63-73 ©IJESET
assumption. They compared results of the two way coupling model with the one way coupling model.
Also they identified that the new model properly conserves energy and account for gravitational
Hoffman and Dowling [24] used seven degree-of-freedom model that properly conserves energy and
predicts the overall features of the engine’s vibratory output. They didn’t utilize the assumption
vibratory state of engine does not influence the loads transmitted from the moving internal
components to engine block. They presented a time and frequency domain comparisons of the model
and experiment results made on test engine at full load at peak torque and rated speeds. Zheng-Dong
Ma and Perkins [25] developed equations of motion for major components of internal combustion
engine using recursive formulation. The derivation equation of motion was automated through the
computer program by the use of C and FORTRAN sub routines. The entire automated procedure
forms the basis for an engine modeling template. Using the template they predicted the engine
responses under free and firing conditions were compared with Adam’s models. The results obtained
by using different bearing models at the crank shaft including linear, non-linear and hydrodynamic
models were discussed in detail. Niccolo [29] presented an innovative approach to
dynamic design that has the significant advantage of allowing dynamic requirements to be specified
from the earliest design stage. They used Genetic algorithm to optimize the dynamic behavior of
engine-sub-frame system and its links to chasis. The optimization minimizes complying with the
static and dynamic constraints. The GA was applied to a multi body model of Engine-mount system to
derive new, improved configurations. Tsuneo Tanaka and Tetsuya [30] Sakai presented a method to
effectively reduce a level of idling vibration in heavy-duty trucks. For that they developed a full
vehicle vibration model using Finite element method. The flywheel velocity and fluctuation in
flywheel speed were the input to this model and the output from the model is engine excitation forces.
D. Geoff Rideout, Jeffrey L. Stein and Loucas S. Louca [33], focused on how the application of
existing decoupling algorithms can lead to systematic decoupled engine models for specific user
defined conditions. They described the decoupling search and model partitioning algorithm, and the
bond graph formalism that facilitates the execution. Also they compared the results of partitioning
algorithm that applied to a balanced and an unbalanced an in-line six-cylinder engine fully coupled
Jae-Yeol Park and Rajendra singh[2], identified the drawback the ignorance on non-proportional
viscous damping in the early design of hydraulic mounts. Because of this drawback rigid body
vibrations are included as and when the proportional damping is considered in the mounts. To rectify
this, they formulated a mathematical model for a non-proportionally damped linear mount and
investigated the torque roll axis of passive mounts. X.Zhang and S.D.Yu[12], developed the rigid
body and flexible body models to predict the torsional vibrations at various load conditions and
different propeller pitch settings of an air craft engine. Here, the rigid body model and Kineto-elastodynamic model are coupled together also a stepped crank shaft model is developed with the help of
finite element modeling. The aerodynamic torque, developed from the blade element geometry,
variations with respect to the speed at the interface of crank shaft and the propeller was obtained.
Augmented Lagrange equations were used to obtain non-linear equations of motion then the small
scale model was developed by applying the component mode synthesis in the equation of motion
without changing the non-linearities. The steady state and unsteady state responses were determined
with the help of Runge-Kutta algorithm. From the results the authors identified the significant
influence of crank shaft flexibility on the dynamical behavior.
Engine produces the vibratory forces due to the unbalanced forces from the engine parts during the
operation. The vibration caused by the engine at the supports is torsional vibration and the
longitudinal vibration. The torsional vibration is caused at the crankshaft due to the fluctuating engine
combustion pressures and engine loads. The longitudinal vibrations are caused at the block and the
mounts by the reciprocating and rotating parts of the engine.
Snyman [20] concerned with minimization of engine vibration in the mounted 4-cylinder internal
combustion engine. They analyzed the mathematical model and the balancing mass and the lead
angles were taken as the design variables. The objective function used in their research is the
International Journal of Engineering Sciences & Emerging Technologies, August 2012.
ISSN: 2231 – 6604
Volume 3, Issue 1, pp: 63-73 ©IJESET
vibratory forces from the engine, transmitted to the engine mounts. The objective function is to be
minimized to minimize the vibratory output of the engine and the Leap frog optimization algorithm is
employed to minimize the objective function. Conti and Bretl [28] presented a new method for
determining an analytical model of rigid body on it mounts and the method is based on data acquired.
They used modal experimental data from an artificial excitation of vibration of test of the article
suspended to ground through mounts as input to the model and the output is rigid body mass
properties and stiffness of the mounts. The extracted modal data for these six modes is input to a least
square algorithm, which was used to compute mass and centre of gravity of location, mass moments
and principal axes of inertia and tri-axial stiffness of mount. Chung–Ha and Clifford.G.Smith Shu
[27], presented simplified method to determine the vibrational amplitude developed by a 4-cylinder
engine when supported on viscoelastic mounts. They modeled the engine parts as rigid bodies
connected to the rubber mounts which were modeled with spring and damping elements. The location,
orientation and stiffness of the mounts can easily be optimized to reduce vibration and noise in the
engine design Nader Vahdati and L. Ken Lauderbaugh Saunders [41], described a high frequency test
machine was that allowed test engineers to study the high frequency performance of rubber mounts.
The mathematical model of the high frequency test machine was presented. Simulation results of the
high frequency test machine showed that with the proper design of the test fixture, and appropriate
selection of the reaction mass and reaction mass mounts, one can perform a high frequency dynamic
stiffness test on rubber mounts at frequencies as high as 5000 Hz. Simulation results indicate that the
weight of the test specimen test fixture needs to be kept to a minimum. In the high frequency test
machine described that it was not possible but very desirable to directly display the test specimen’s
dynamic stiffness.
P.Charles et. al [13], investigated the fault detection related to diesel engine combustion based on the
crank shaft torsional vibration. They used encoder signal, to measure the speed of the shaft, to develop
the instantaneous angular speed (IAS) wave form which is the significance of torsional vibration.
They used IAS and fast Fourier transform (FFT) to monitor the 16-cylinder engine.. In this
investigation enhanced FFT was used by improving signal processing to determine the IAS signal.
They also introduced a novel method to present IAS signal through poal coordinates. Fredrik Ostman
and Hanna T. Toivonen[14], were presented a method to reduce the torsional vibration in
reciprocating common rail diesel engines. They identified that cylinder wise non-uniform torque was
the reason for the increased torsional vibration and stresses at the mechanical parts of the engine. The
non-uniform torque in each cylinder can be balanced by adjusting and controlling the cylinder wise
fuel injections so that the balancing of torque will be obtained. They proposed an active cylinder
scheme to reduce the torsional vibration. The model relates the consecutive cylinder firings and the
torque and the output of the model were used to adjust the cylinder wise fuel injections to compromise
the non-uniformity of the torque. Zhang Juhong and Han Jun[15], investigated the design
modifications for a new engine that would reduce low-fequency-radiated noise and vibration below
the existing production of engine and optimizing the noise and vibration characteristics. The authors
considered the combustion forces, main bearing reaction forces including damper function and
flywheel whirling, piston side forces, cam shaft bearing reaction forces, impact of valve opening and
closing, valve train forces from gear/chain and drive train forces and moments as relevant excitation
forces for noise and vibration harshness(NVH). Considering all the factors the authors developed a
complex simulation model to calculate the NVH. The model used in this study is a combination of
Finite Element Analysis (FEA) and Multi Body Analysis (MBA). The FEA models were used to
simulate and to analyze the vibrational behaviors of the components and the MBA was used to
simulate the whole body movement. Rajendran and Narasimhan [26] studied the effect of combined
torsional and bending free vibrations in the single cylinder engine crank shaft. For that the developed
a all-finite-element model developed and the results obtained indicate that the inertial coupling
introduced influences the free vibration characteristics. From the result they shown that, under such
condition, modeling the crank shaft as a pure torsional system would involve considerable error.
H. Ashrafiuon [31]et al focused on frequency response of an aircraft engine to determine harmonic
forces. The locations, orientations, and types of mounts used are all critical in minimizing the
transmitted forces. They also presented the results for a specific aircraft engine. The methodology of
this work was applicable to most of the vibration isolation systems. H.R. Karimi and B. Lohmann[33]
introduced a computational solution to the finite-time robust optimal control problem of the vehicle
International Journal of Engineering Sciences & Emerging Technologies, August 2012.
ISSN: 2231 – 6604
Volume 3, Issue 1, pp: 63-73 ©IJESET
engine–body vibration system based on Haar wavelets. The robust optimal trajectory and finite-time
robust optimal control of the vehicle engine–body vibration system were obtained approximately by
solving the linear algebraic equations instead of solving the differential equations. Hongkun Li, et.
al[34] used Hilbert spectrum analysis that was applied to diesel engine pattern recognition. They
showed that after pre-processed by the wavelet packet, the HS was more accurate and convenient for
real diesel vibration signal analysis. In this paper, experimental data of a diesel fuel injection system
of different conditions was used to evaluate the improved methodology for system pattern recognition
and fault diagnosis. Claes Olsson [35] considered a general vibration isolation problem covering
arbitrarily, structurally complex machines and receivers, whereas 1-DOF isolation and a single
feedback sensor were assumed, ie single-input single-output (SISO) vibration isolation problems. The
objectives of this paper were investigating the impacts of structure flexibility on two different open
loop transfer functions, the consequences of neglecting flexibility on closed loop performance and
stability of an automotive vibration isolation application. Borislav Klarin et. al [36] developed a
numerical model based on multi body dynamics (MBD) and finite element method (FEM) and the
model was simulated at different speeds of the engine to predict the torsional vibrations at the crank
shaft and engine mount vibration and structural borne noise. Both the experimental and numerical
natural modes analysis was done and results were compared in the form of modal assurance criterion.
The finite element model was validated by modal analysis of whole engine in constrained conditions.
Konrad Kowalczyk et. al [37] discussed the active vibration control (AVC) system that generates
dynamic forces to cancel the effect of incoming excitations. They presented an overview of modelbased development of control algorithms, a short description of system components. They also
described AVC system installed in the test vehicle and an explicated presentation of tools for the
development of control functions. X. Moreau et. al [42], proposed a method analyse the vibration
isolation. Initially, they presented the derivative models that were used to model viscoelastic material
properties of suspension system. After that by taking into account the vibration sources and the sprung
mass uncertainties they described the single-degree-of-freedom model. Then, the design for
suspension was transformed into a design for robust controller, independently of whether it is active,
semi-active or passive. The use of fractional derivative models not only permits optimisation of just
four parameters, showing the ‘compactness’ of the fractional derivative operator, but also leads to
robustness of suspension performance to uncertainty of the sprung mass. At the last they presented a
called engine mount system.
Jae-Yeol Park and Rajendra Singh [38], identified ignorance of non-proportional theories or design
methods in viscous damping formulations. In the earlier studies, though the torque roll axis
decoupling is still theoretically possible with proportional damping assumption rigid-body vibrations
are needed to be coupled whenever non-proportional damping is introduced to the mounting system.
They rectified the difficulty by re-formulating the problem for a non-proportionally damped linear
system and recognized that significant damping will be possible with passive mounts. Also they
examined the torque roll axis decoupling paradigm by keeping given mount rate ratios, mount
locations and orientation angles as important design parameters. Based on the above a derived two
eigen-value problems and necessary axiom for a mode in the torque roll axis direction in terms of
stiffness and damping matrices that are on currently satisfied and both steady state and unsteady state
responses and the extent of coupling or decoupling is quantified. Results shown that, the torque roll
axis for a mounting system with non-proportional damping was decoupled, when one of the damped
modes lies in the torque roll axis direction. Z.K. Peng and Z.Q. Lang [3], invented a new concept of
output frequency response function (OFRF) through an effective algorithm for the purpose of design
on non-linear passive engine mounts for the effective vibration isolation. They developed an
analytical relationship between output frequency response and the non-linear parameters by the
polynomial type non-linear differential equation. The objective of this analysis is made to analytically
reveal the effect of non-linear characteristics of passive engine mount on the frequency response and
how it facilitates in the design of engine mounts. The model was simulated to validate the output
frequency response of the system. The author strongly suggests that the OFRF results shows
significant importance in the analysis, design and selection of non-linear engine mounts. Also this
OFRF model can be extended for the multi-degree of freedom.
International Journal of Engineering Sciences & Emerging Technologies, August 2012.
ISSN: 2231 – 6604
Volume 3, Issue 1, pp: 63-73 ©IJESET
The unbalanced forces produced from the engine are transferred to the engine supporting members
and causes the structure borne vibrations. To reduce the vibratory forces from the engine to the
structures, the engine is supported by the damping members called vibration isolators (engine
mountings). The mountings are the final most sources to reduce the vibratory forces by its damping
property. Mounts are designed to satisfy two important criteria the first is the support function,
reduction of the large amplitude vibration, at lower resonance bands. It requires the mountings to have
higher stiffness and damping. The other is noise control, the mountings have to reduce the noise in the
supporting structures induced by small amplitude vibration of the engine, at higher bands. It requires
the mountings to posses lower stiffness and damping. These two requirements are contradictory, and
the main aim in the design of engine mounts is to stabilize these two different conflicting
Fig.1 Engine model
Fig.2 Typical engine mounting system
Yunhe Yu, Saravanan M.Peelamedu, Nagi G.Naganathan, Rao V.Dukkipati[19], made a survey on
automotive engine mounts. The survey was on the basis of overview and development of different
engine mounts and optimization of the engine mount systems. They made a study about the ideal
engine mounting system which would isolate the vibration excitations from the engine and shown the
concentration requirement of improvement of frequency and amplitude dependent properties. They
explored how the rubber mounts trade-off the static deflection and provides the vibration isolation and
what way the hydraulic mounts provides the better performance than the rubber mounts. At the final
they reviewed about the different methods of optimization of engine mounting systems and suggested
that active mounting systems would be considered for future trend. A.R. Ohadi and G.
Magsoodi[1],Developed a mathematical model by assuming the hydraulic mounts as lumped
parameter model to investigate the non-linear parameters, such as inertia and decoupler resistances
and the effect of non-linearity in hydraulic engine mounts. The model was developed such that the
model includes the forces and moments due to engine mounts, pistons, balancing masses. The model
was simulated at different speeds of the engine. The results obtained were in terms of base forces
transmitted to the mounts for both hydraulic and rubber mounts. The comparison were made and
found that the efficiency of the hydraulic mount was more at the low frequency regions. J J Kim and
H Y Kim[10], suggested the optimum design using parametric design process with the help of the
parameter optimization method. The method was developed using finite element based computer
program and the program determines the shape of engine mount that fulfils the requirement of the
engine mount stiffness. They used a bush type engine rubber mount model for a passenger car. The
developed model was considered as basic model and modification were made for the large
deformation and endurance analysis of the rubber mounts. The model was simulated in the bush type
rubber mount for optimization of the shape of the mount and subsequently for the desired stiffness
values. Qian Li et. al[40], predicted the fatigue life of a rubber mount by combining test of material
properties and finite element analysis (FEA). They arrived the fatigue life equation for the natural
rubber material based on uniaxial tensile test and fatigue life tests of the natural rubber and the strain
distribution contours and the maximum total principal strains at different loads in the x and y
directions were obtained using FEA method. The author first obtained and analyzed were the critical
International Journal of Engineering Sciences & Emerging Technologies, August 2012.
ISSN: 2231 – 6604
Volume 3, Issue 1, pp: 63-73 ©IJESET
region cracks prone to arise. The maximum total principal strain, fatigue parameter, was used to
predict the rubber mount fatigue life from the fatigue life equation and the prediction method was
validated with help of the results of the fatigue life test rig.
Thanh Quoc and Kyoung Kwan Ahn[5], developed a theoretical model to isolate the vibrations from
engine and to control the area of inertia track under shocks and multi-signal excitation in the passive
hydraulic engine mounts. The authors introduced a controllable inertia track and made considerable
changes in the dynamic properties with respect to the area of inertia track. They identified that the
dynamic properties were varied as the inertia track was changed. The results of the numerical
simulations showed that the vibration isolation of the passive engine mount was affected by changing
the inertia track area and the optimization, developed based on the frequency band and magnitude, of
dynamic properties was made. The authors were also identified that many of the researcher were not
considered the displacement of the mount in the reduction of dynamic stiffness to reduce the force
transmitted to chassis. Bo-Ha Lee and Chong-Won Lee[6], studied and developed a new type of
active control engine mount (ACM), feed forward control based electromagnetic engine mount that
illustrates both the active and passive characteristics of ACM such that the model includes the
vibration isolation estimation algorithm, current shaping controller and an enhanced model for ACM.
The authors used two sensors, one is to measure the force transmitted to the ACM and the other to
monitor the position and hence acting as position feedback control. The results obtained from the
prototype were depicted that the ACM behavior at the dynamic conditions at the desired range of
frequency were found to be accuracy. They also showed that the vibration estimation algorithm
efficiently explored the anti-vibration signals for the vibration isolation and the proto type ACM
effectively isolated the vibration forces from the engine. Lee Jun Hwa and Rajendra Singh[7], states
that hydraulic mounts has at least one inertia element even at low frequencies. Thus the constraints at
the input and output of the hydraulic mount are not identical and like a conventional spring. So the
mechanical model analogous to the hydraulic mounts that has spring, dashpot and mass elements will
lead to the poor results in the system analysis. The author critically examined the dynamic response of
the hydraulic mounts using mechanical models. They clearly depicted that the models must not be
employed where both the ends of hydraulic mount move and the models will work only if one of the
end is fixed.
Taehym Shim and Donald Margolis[8], developed controlled equilibrium mounts (CEM) for an
aircraft engine which is much smoother than usual mounts to isolate the engine vibration. The CEM
uses the additional control effect of equilibrium position of mount by the by-pas air from the engine.
The Equilibrium position of mounts can be obtained by pressurizing and exhausting of air in to the
mounts by the control valves. They developed a CEM simulation model considering the
thermodynamic effects and heat transfer characteristics of air, valve control logic and equation of
motion. The model consists of parts like conventional mount, expandable volume, control-valve and
supply system. The electrometric part of the mount provides the basic isolation and the expandable
volume provides the additional isolation by pressurized/exhausted air, supplied from the engine, with
help of control valves. The simulations were made to find mount displacements during taxi, climp,
cruise and decent conditions of the air craft. The authors stated that the heat transfer rate between inlet
and outlet air was excessive and will be considered in future study. J.Christopherson and G.Nakhgie
Jazar[9], investigated the linear and non-linear aspects of two distinct passive hydraulic engine
mounts with floating decoupler and with direct decoupler. Both the decoupler mechanisms were used
to control the amplitude dependent behavior of the mount. In the first type, the fluid is forced through
the inertia track due to relative motion between the engine and the chassis and this design relies upon
the appropriate combination of inertia track and decoupler gap size. In the second type, the decoupler
directly connected to the engine mount and its motion is directly controlled by the engine motion of
the engine and the chassis. The linear and non-linear mathematical models of the both type were
simulated and from the results it has been identified that the direct decoupler mount exhibits the
lowest transmissibility in low frequency domains whereas the floating decoupler shown better
performance as the excitation frequency increases. The non-linear response solutions of the both
mounts were validated by direct comparison with the linear counter parts and it has been identified
that the similarity between the solution regions sufficiently removed the resonance in the non-linear
modeling They also experienced difficulties in the mathematical modeling of the direct decoupler
International Journal of Engineering Sciences & Emerging Technologies, August 2012.
ISSN: 2231 – 6604
Volume 3, Issue 1, pp: 63-73 ©IJESET
when using the new method, energy-rate method, for the analysis of stability of the parametric
J.S.Lee and S.C Kim[11], focused on the performance enhancement of engine mount rubber(EMR) by
adopting a form a design optimization approach. The optimal design was arrived by considering the
material stiffness and fatigue strength of a rubber. The objective of the optimal design was made to
minimize both the weight and the maximum stress of the EMR and to maximize the fatigue life cycle
subjected to constraints on static stiffness of rubber. The number of life cycles associated with the
fatigue strength should be increased as much as possible under the acceptable material stiffness
behavior. Such design requirements made possible through multi objective optimization method. In
the context of approximate optimization a back propagation neural networks was used to construct
global response surface between input design variables and output responses of objective functions. A
micro-genetic algorithm was adopted as global optimizer in order to consider the inherent nonlinearity analysis of the model. Jun-Hwa Lee and Kwang-Joon Kim[16], developed viscous damping
model for hydraulic engine mount and represented the model in terms of design variables. The design
variables are geometry of inertia track, resultant stiffness and damping characteristics. The parametric
studies were presented the relation between the equivalent viscous damping coefficient and the design
variables. The authors discussed the lumped parameter and dynamic performance characteristics of
the mounts. Based on these two combinations the efficient design technique for the hydraulic mount
was made. The authors state that relation between the design variables and the dynamic characteristics
will be helpful in design modification and initial design of hydraulic mounts so that the desirable
performance of the mount will be obtained.
Li-Rong Wang [17], developed a non-linear parameter model to determine the dynamic
characteristics of hydraulically damped mount (HDM). The results of dynamic characteristics
obtained from the mathematical model with fixed-decoupler were compared with the experimental
values of the typical HDM and verifies the effectiveness of the modeling. The HDM’s working
methodology was clarified by super positioning the performance with the rubber mount, inertia track
and. The authors also made a analysis of parametric effect to bring out the influence of structural
design parameters on the vibration isolation performance of the HDM. The authors identified the
following : modeling technology of rubber viscoelasticity, fluid-structure interaction between rubber
parts and fluid in chambers and frequency and amplitude dependent characteristics of volumetric
stiffness of upper chamber for future study. Lirng Wang et. al [18], developed a mixed finite element
formulation to analyze hydrostatic fluid-structure characteristics of hydraulically damped mount
(HDM). They developed a set of equations for the fluid transfer analysis of mass flow rate and
pressure difference between the lower and upper chambers. The fluid structure interaction finite
element (FSI FE) modeling of lower and upper chamber was done they were bridged and finally the
HDM integrates the FSI FE and fluid transfer characteristics models. The author states that such type
of integration of hydrostatic FSI approach with lumped parameter modeling of fluid track can reduce
the computational cost of FSI in HDM.
Yougn Kong Ahn [14], developed a methodology to improve the non-linear hydraulic engine
mount by an optimal design process. The hydraulic mount with inertia track and decoupler has
variation in property based on the disturbance frequency range and is small at higher excitation. For
that they developed two linear models, one is low high frequency range and the other for high
frequency range. The combination of two models also was used in optimization of the hydraulic
mount. For the optimal design of the non-linear fluid engine mount with inertia track and decoupler
they used sequential quadratic programming (SQP) technique to minimize the transmissibilities of the
fluid mount. The frequencies used in the SQP for low frequency range model and high frequency
range model were calculated from the simulation of the mathematical model. To obtain effective
vibration for the high and low frequency range models the SQP was combined with low and high
frequency range models. The design parameters that greatly affect vibration isolation effectiveness
were considered as design variables such as the effective piston area, inertia track, inertia of
decoupler, inertia track resistance, decoupler resistance, rubber stiffness and compliance in top and
bottom chambers. A. Geisberger et. al [39], developed the non-linear model such that the model is
able to capture both the low- and high-frequency behavior of a hydraulic engine mount and the model
was validated with the help of unique experimental set up.The results of the model here provided a
significant improvement over existing models by considering all non-linear aspects of a hydraulic
International Journal of Engineering Sciences & Emerging Technologies, August 2012.
ISSN: 2231 – 6604
Volume 3, Issue 1, pp: 63-73 ©IJESET
engine mount. They made Enhancements on the existing non-linear models to include a continuous
function that follows a simple and effective approach to capture the switching effect and leakage
through the decoupler, and upper chamber bulge damping. The developed model also showed
appropriate system response over the full range of loading conditions. From the experimental set up
initially the individual components of the mount model was verified and then the behavior of the
whole assembly was verified. The data obtained from the results gave the relative importance of
several damping, inertia and stiffness terms and the measured responses of the mounts at various
frequencies and amplitudes are compared with the results of the mathematical model. Daniela Siano
et al [43], used Multi-Body and FEM-BEM methodology used to predict the noise radiated by a
turbocharged 4-cylinder diesel .A Multi-Body Dynamic Simulation (MBDS) of the engine was
carried out by simulating an engine to estimate the forces acting on the cylinder block. The dynamics
of the engine is described taking into account the effects of the gas pressure and the inertia forces of
the moving parts. In this work to identify the real engine operating behaviour, both the crank and
the block have been considered as flexible bodies. The cylinder block excitations were used to
evaluate the engine radiated noise with the MATV methodology.
Based on the literatures from various research articles for the engine various multibody modeling of
engines, engine vibration testing and measurement techniques used and the various mountings used to
reduce the vibration and recent technologies invented and adopted. The following observations are
made on the above literature survey:
• Many of the researchers considered the engine as rigid body model not the flexible one.
• Meager number of articles only took the forces from the engine to the mount for the
mathematical modeling as two way coupling.
• Less research were made by combining the both the torsional and longitudinal vibrations.
• For the determination of the engine vibration calculations most of them were not considered
the engine combustion force variations.
• In the vibration modeling of the vehicles the engine vibration modeling and road vibration
modeling were considered separately not as single model.
• The recent developments of the mounts on the hydraulic and electromagnetic mounts were
used as the isolator not the conventional rubber mounts.
• A simple and versatile model required to be developed which includes the multibody
dynamics of engine and dynamics characteristics of the rubber or hydraulic mounts to analyse
the vibratory characteristics of the power plant.
Fig.3 Vibration analysis flow chart
International Journal of Engineering Sciences & Emerging Technologies, August 2012.
ISSN: 2231 – 6604
Volume 3, Issue 1, pp: 63-73 ©IJESET
A.R. Ohadi, G. Magsoodi ,Simulation of Engine Vibration On Non-Linear Hydraulic Engine Mounts. J.
of Vibration and acoustics. (2007) 129 : 417-424
Jae-Yeol Park, Rajendra singh, Effect of non-proportional damping on the torque roll axis decoupling of
engine mounting system. J.of Sound and Vibration. (2008) 313: 841-857.
Z.K. Peng, Z.Q. Lang , The effect of non-linearity on the output frequency response of a passive engine
mount. J. of sound and vibration . (2008) 318: 313 328.
Sudhir Koul, Anoop Dhingra, Tomothy G Hunter, Frame flexibility effects on engine mount optimization
for vibration in motor cycles. J. of sound and vibration. (2007) 129 : 590-600.
Thanh Quoc, Kyoung Kwan Ahn, A new type of semi-active hydraulic engine mount using controllable
area of inertia track. . J. of sound and vibration (2010) 329 : 247-260—5
Bo-Ha Lee, Chong-Won Lee , Model based feed-forward control of electromagnetic type active enginemount system. J. of sound and vibration (2009) 323 : 574-593.
Lee Jun Hwa , Rajendra Singh, Critical analysis of analogous mechanical models used to describe
hydraulic engine mounts. J. of sound and vibration(2008) 311 : 1457-1464.
Taehym Shim, Donald Margolis, Controlled equilibrium mounts for aircraft engine isolation. J. of control
engineering practice. (2006) 14 : 721-733.
J.Christopherson, G.Nakhgie Jazar, Dynamic behavior comparison of passive engine mounts Part-I:
Mathematical Analysis. J.of sound and vibration (2006) 290 : 1040-1070.
J J Kim, H Y Kim, Shape design of an engine mount by a method of parametric shape optimization.
Proceedings of Institutions of Mechanical Engineers (1997) 211 Part-D :155-159.
J.S.Lee, S.C Kim, Optimal design of engine mount rubber considering stiffness and fatigue strength. J. of
Automobile engineering (2007) 221 Part-D : 823-829.
X.Zhang, S.D.Yu, Torsional vibration of crank shaft in an engine - propeller non-linear dynamical
system. J. of sound and vibration(2009) 319 : 491-514.
P.Charles, Jyothi. Sinha, F.Gu, L.Lidstone, A.D.Ball, Detecting the crank shaft torsional vibration of
diesel engines for combustion related diagnosis. J. of sound and vibration (2009) 321: 1171-1185.
Fredrik Ostman, Hanna T. Toivonen, Active vibration control of reciprocating engines. Control
Engineering Practice(2008)16:78-88.
Zhang Juhong, Han Jun, CAE process to simulate and optimize engine noise and vibration. Mechanical
Systems and signal processings (2006) 20 : 1400-1409.
Jun-Hwa Lee, Kwang-Joon Kim, An efficient technique for the design of hydraulic engine mount via
design variable – Embedded damping modeling. J. of sound and vibrations (2005) 127 : 93-99.
Li-Rong Wang, Zhen-Hua Lu, Ichiro Hagiwara, Analytical analysis approach to non-linear dynamic
characteristics of hydraulically damped rubber mount of vehicle engine. J. of non-linear dynamics (2010)
61: 251-264.
Lirng Wang, Zhenhua Lu, Ichiro Hagiwara, Hydrostatic fluid structure characteristic analysis of
hydraulically damped rubber mounts. Proceedings of World congress in engineering (2009) Vol II.
Yunhe Yu, Saravanan M.Peelamedu, Nagi G.Naganathan, Rao V.Dukkipati, Automotive engine
mounting systems- A survey. J.of dynamic systems, measurement and control (2001) 123 : 185-194.
J.A.Snyman, P.S.Heyns, P.J.Vermeulen (1995) Vibration isolation of a mounted engine through
optimization. Mech. Mach. Theory 30 (1) : 109-118.
D.M.W.Hoffman, D.R.Dowling (1999) Limitations of rigid body descriptions for heavy-duty diesel
engine vibration. ASME Journal of Engineering for Gas Turbine and power 121 : 197-204.
Deana M. Winton, David R. Dowling (1997) Modal content of Heavy-duty diesel engine block vibration.
SAE Paper#971948.
D.M.W.Hoffman, D.R.Dowling (2001) Fully coupled internal combustion engine dynamics and vibration
– part I: Model development. ASME Journal of Engineering for Gas Turbine and power 123 : 677-684.
D.M.W.Hoffman, D.R.Dowling (2001) Fully coupled internal combustion engine dynamics and vibration
– part II: Model-Experiment comparision. ASME Journal of Engineering for Gas Turbine and power 123
: 685-692.
Zheng-Dong Ma, Noel C.Perkins (2003) An efficient multibody dynamics model for internal combustion
engine sytems. Multibody System Dynamics 10: 363-391.
S.Rajendran, M.V.Narasimhan (1997) Effect of inertia variation due to reciprocating parts and
connecting rod on coupled free vibration of crank shaft. ASME Journal of Engineering for Gas Turbine
and power 119 : 257-263.
Chung-Ha Suh, Clifford G.Smith (1997) Dynamic simulation of engine mount system. SAE
P.Conti, J.Bretl (1989) Mount stiffness and inertia properties from modal test data. ASME Journal of
Vibrations and Acoustics, Stress and Reliability in Design 111 : 134-141.
International Journal of Engineering Sciences & Emerging Technologies, August 2012.
ISSN: 2231 – 6604
Volume 3, Issue 1, pp: 63-73 ©IJESET
Niccolo Baldanzini, Davide Carprioli, Marco Pierini (2001) Designing the dynamic behaviour of an
engine suspesion system through genetic algorithm. ASME Journal of Vibrations and Acoustics 123 :
Tsuneo Tanaka, Mitsuo Iwahara, Tetsuya Sakai (1996) The optimization of engine vibration reduction by
simulation analysis. SAE#962203 .
Ashrafiuon, H., and Natraj, C (1992) Dynamic Analysis of Engine-Mount Systems, ASME J. Vibr.
Acoust., 114 : 79–83.
R.Karimi B. Lohmann .(2007) Haar wavelet-based robust optimal control for vibration reduction of
vehicle engine–body system. Electr Eng 89: 469–478.
D. Geoff Rideout, Jeffrey L. Stein, Loucas S. Louca,(2008) “Systematic Assessment of Rigid Internal
Combustion Engine Dynamic Coupling” ASME Journal of Vibrations and Acoustics ,130: 022804-1-12.
Hongkun Li, Xiaojiang Ma, Hongying Hu, and Quanmin Ren(2006),” Investigation on Reciprocating
Engine Condition Classification by Using Wavelet Packet Hilbert Spectrum”, L. Jiao et al. (Eds.): ICNC
2006, Part II, LNCS 4222, pp. 588 – 597.
Claes Olsson (2007), Structure Flexibility Impacts on Robust Active Vibration Isolation Using Mixed
Sensitivity Optimization, Journal of Vibration and Acoustics,129 : 179-192.
Borislav KLARIN, Carmine NOLFE, Teresa PAPPALARDO, Corrado GRASSO (2005), Experimental
And Numerical Power Unit Vibration Analysis”, 22nd DANUBIA-ADRIA Symposium on Experimental
Methods in Solid Mechanics.
Konrad Kowalczyk, Hans-Jurgen Karkosch, Peter M. Marienfeld, and Ferdinand Svaricek (2006), “Rapid
Control Prototyping of Active Vibration Control Systems in Automotive Applications”, Proceedings of
the 2006 IEEE Conference on Computer Aided Control Systems Design.
Jae-Yeol Park, Rajendra Singh, Effect of non-proportional damping on the torque roll axis decoupling of
an engine mounting system, Journal of Sound and Vibration 313 (2008) 841–857.
A. Geisberger, A. Khajepour and F. Golnaraghi, Non-linear modelling of hydraulic mounts: Theory and
experiment, Journal of Sound and vibration (2002) 249(2) : 371-397.
Qian Li , Jian-cai Zhao , Bo Zhao, Fatigue life prediction of a rubber mount based on test of material
properties and finite element analysis, Journal of Engineering Failure Analysis (2009) 16 :2304–2310—
Nader Vahdati, L. Ken Lauderbaugh Saunders, High frequency testing of rubber mounts, ISA
Transactions (2002) 41 : 145–154.
X. Moreau, C. Ramus-S, A. Oustaloup, Fractional Differentiation in Passive Vibration Control, Nonlinear
Dynamics (2002)29: 343–362.
Daniela Siano,Salvina Giacobbe, Fabio Bozza, Noise Prediction of a Multi-Cylinder Engine Prototype
Using Multi-Body Dynamic Simulation (2011), SAE- 2011-24-0216
T. Ramachandran, received the B.E. degree in Mechanical Engineering from Thiyagarajar
College of Engineerin, Madurai, and the M.E. (Thermal) from Madurai Kamaraj University,
Madurai, and pursuing Ph.D degree in Anna University Trichy. He has 11 years of teaching
experience at various institutes. At present he is working as Associate Professor in PSNA College
of Engineering and Technology. His research interests are IC engines, Vibrations, multibody
dynamics and optimization techniques.
K. P. Padmanaban, received the B.E. degree in Mechanical Engineering from Thiyagarajar
College of Engineering, Madurai, and the M.E. (Engg. Design) from Coimbatore Institute of
Technology, Coimbatore and pursued Ph.D. degree from Anna University Chennai. He has 15
years of teaching experience at different engineering colleges and guiding more than 10 Ph.D
scholors. He has published 20 research papers in international journals and more than 25 research
papers in the international conferences. At present he is the Director of SBM College of
Engineering and Technology, Dindigul. His research areas are FEA, vibration, fixture design and
Optimization techniques.
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