Abstract

Hydraulic mounts used in vehicles for better isolation of vibrations were often approximated by lumped or mechanical mass-damper-spring (m-c-k) models, although deficiency in such modeling was pointed out and “hydraulic” modeling was proposed as an alternative. In this paper, a brief review on the mechanical m-c-k modeling and “hydraulic” modeling of the hydraulic mounts is presented. A simplest system consisting of a single mass and a hydraulic mount is used to illustrate both equivalence and difference in a closed form between the two modeling approaches. Then, modal analyses are done on an apparently three degrees-of-freedom (DOF) quarter car with a hydraulic mount, where the key idea is to use an internal variable for the movement of fluid mass which is responsible for a “latent” vibration mode. Equations of motion for the apparently 3DOF system, 4DOF system in fact, by the two modeling are formulated. Modal parameters by the proposed “hydraulic” modeling of the hydraulic mount are compared with those by the m-c-k modeling. Forced responses to transient base excitations are also compared between the two modeling approaches to illustrate how much errors can arise in the frequency and time domain analysis. To be more realistic, the modal and forced response analysis on a full car of an apparently 10DOF (3DOF for powertrain, 3DOF for car body, and 4DOF for knuckles and tires) with two more DOF internally for two hydraulic mounts between the powertrain and car body is presented.

References

References
1.
Brach
,
R. M.
, and
Haddow
,
A. G.
,
1993
, “
On the Dynamic Response of Hydraulic Engine Mounts
,”
SAE Technical Paper
,
931321
.
2.
Lee
,
J.-H.
, and
Singh
,
R.
,
2008
, “
Critical Analysis of Analogous Mechanical Models Used to Describe Hydraulic Engine Mounts
,”
J. Sound Vib.
,
311
(
3–5
), pp.
1457
1464
. 10.1016/j.jsv.2007.10.021
3.
Flower
,
W. C.
,
1985
, “
Understanding Hydraulic Mounts for Improved Vehicle Noise
,”
SAE Technical Paper
,
850975
.
4.
Yu
,
Y.
,
Naganathan
,
N. G.
, and
Dukkipati
,
R. V.
,
2001
, “
A Literature Review of Automotive Vehicle Engine Mounting Systems
,”
Mech. Mach. Theory
,
36
(
1
), pp.
123
142
. 10.1016/S0094-114X(00)00023-9
5.
Colgate
,
J. E.
,
Chang
,
C. T.
,
Chiou
,
Y. C.
,
Liu
,
W. K.
, and
Keer
,
L. M.
,
1995
, “
Modeling of a Hydraulic Engine Mount Focusing on Response to Sinusoidal and Composite Excitations
,”
J. Sound Vib.
,
184
(
3
), pp.
503
528
. 10.1006/jsvi.1995.0330
6.
Golnaraghi
,
M. F.
, and
Jazar
,
G. N.
,
2001
, “
Development and Analysis of a Simplified Nonlinear Model of a Hydraulic Engine Mount
,”
J. Vib. Control
,
7
(
4
), pp.
495
526
. 10.1177/107754630100700402
7.
Golnaraghi
,
M. F.
, and
Jazar
,
G. N.
,
2002
, “
Nonlinear Modeling, Experimental Verification, and Theoretical Analysis of a Hydraulic Engine Mount
,”
J. Vib. Control
,
8
(
1
), pp.
87
116
. 10.1177/1077546302008001519
8.
Lee
,
J.-H.
,
Kim
,
K.-J.
,
Won
,
K.-M.
, and
Kang
,
K.-T.
,
2001
, “
An Analytic Technique for Making a Linear Model of a Hydraulic Mount
,”
Korean Soc. Mech. Eng.
,
1
(
2
), pp.
410
415
.
9.
Lee
,
J.-H.
,
Bae
,
M.-S.
, and
Kim
,
K.-J.
,
2003
, “
Limitations of Mechanical Model With Lumped Mass in Representing Dynamic Characteristics of Hydraulic Mount
,”
SAE Technical Paper
,
2003-01-1466
.
10.
Yoon
,
J.-Y.
, and
Singh
,
R.
,
2010
, “
Dynamic Force Transmitted by Hydraulic Mount: Estimation in Frequency Domain Using Motion and/or Pressure Measurements and Quasi-Linear Models
,”
Noise Control Eng. J.
,
58
(
4
), pp.
403
419
. 10.3397/1.3449082
11.
Yoon
,
J.-Y.
, and
Singh
,
R.
,
2011
, “
Estimation of Interfacial Forces in a Multi-Degree of Freedom Isolation System Using a Dynamic Load Sensing Mount and Quasi-Linear Models
,”
J. Sound Vib.
,
330
(
18–19
), pp.
4429
4446
. 10.1016/j.jsv.2011.04.033
12.
Kim
,
M.-R.
,
Kim
,
K.-J.
,
Lee
,
K.-I.
, and
Bae
,
B.-K.
,
2017
, “
10-Degree of Freedom Modeling of Full Car Based on Base Excitation Modal Testing
,”
Trans. Korean Soc. Noise Vib. Eng.
,
27
(
6
), pp.
684
690
. 10.5050/KSNVE.2017.27.6.684
13.
Guo
,
R.
,
Gao
,
J.
,
Wei
,
X.-K.
,
Wu
,
Z.-M.
, and
Zhang
,
S.-K.
,
2017
, “
Full Vehicle Dynamic Modeling for Engine Shake With Hydraulic Engine Mount
,”
SAE Technical Paper
,
2017-01-1908
.
14.
Lee
,
J.-H.
, and
Kim
,
K.-J.
,
2005
, “
An Efficient Technique for Design of Hydraulic Engine Mount Design Variable-Embedded Damping Modeling
,”
Trans. ASME J. Vib. Acoust.
,
127
(
1
), pp.
93
99
. 10.1115/1.1855930
You do not currently have access to this content.