Effect of Intentional Dry Friction Damping on the Performance of an Elastomeric Engine Mount

2010 ◽  
Author(s):  
Caner Boral ◽  
Ender Cig˘erog˘lu ◽  
I˙brahim Korkmaz
Keyword(s):  
Dry Friction ◽  
Vibration Isolation ◽  
Wide Frequency Range ◽  
Friction Damper ◽  
Friction Damping ◽  
Automotive Engine ◽  
Engine Mounts ◽  
Initial Cost ◽  
Engine Mount ◽  
Dry Friction Damping

Automotive engine mounts are used to protect engine from road irregularities and to isolate transmission of vibrations created by the engine which have a drastic effect on the noise generated inside the passenger cabin. Most common types of engine mounts are elastomeric and hydraulic mounts, the former having better vibration isolation characteristics whereas the latter displays better shock isolation. Elastomeric mounts are widely used for their low initial cost, while hydraulic mounts with inertia track and decoupler are chosen for their good vibration isolation and shock excitation characteristics. However, hydraulic mounts with inertia track and decoupler are not appropriate for small segment and commercial vehicles due to their high initial cost. In this paper, the effect of the addition of a dry friction damper on the performance of elastomeric automobile engine mounts is investigated. Results showed that addition of dry friction damping to the elastomeric engine mount significantly improves the transmissibility throughout a wide frequency range where the best results are obtained at the resonance frequency.

Experimental Study of Dynamic Characteristics of Dry Friction Damping of Turbine Blade Steel

2013 ◽  
Vol 690-693 ◽  
pp. 1979-1982 ◽  
Author(s):  
Peng Fei Zhao ◽  
Qiang Zhang ◽  
Jun Wu ◽  
Di Zhang
Keyword(s):  
Dry Friction ◽  
Turbine Blades ◽  
Initial Pressure ◽  
Relative Displacement ◽  
Radius Of Curvature ◽  
Response Analysis ◽  
Friction Damper ◽  
Friction Damping ◽  
Stick Slip ◽  
Dry Friction Damping

For lot of structures, especially turbine blades, damper can dissipate the vibration energy by friction. Investigating the property of metal dry friction damping can give many usable data for response analysis of damping blade which is important in damped blade designs. The paper constructs an experimental rig and carries out experiment with pieces having radius of curvature 6mm, 12mm and 24mm. The relative displacement between contact surfaces and the friction force changed with time were obtained for different initial pressure and frequency of exciting force. Hysteresis curves of dry friction damper were derived. The variations of friction coefficient of stick-slip area, equivalent stiffness and equivalent damping were calculated based on experimental data.

Stability Analysis of a Vibrational System Subject to Negative Viscous Damping and Displacement-Dependent Dry Friction Damping

2003 ◽  
Author(s):  
Aldo A. Ferri ◽  
Wayne E. Whiteman
Keyword(s):  
Stability Analysis ◽  
Friction Force ◽  
Dry Friction ◽  
Effective Means ◽  
Viscous Damping ◽  
Friction Damper ◽  
Friction Damping ◽  
Fan Blade ◽  
The Stability ◽  
Dry Friction Damping

A stability analysis is conducted of an autonomous single-degree-of-freedom system damped with negative viscous damping and a displacement-dependent Coulomb friction force. The geometry of the dry friction damping element yields a friction force that grows linearly with the system displacement. The most direct application of this system is in the study of a turbomachinery blade with shroud interfaces designed to achieve this geometry. Recent studies have shown that the damping of systems with this type of displacement-dependent dry friction force resembles linear structural damping and suggests that this arrangement may be an effective means of flutter suppression in these turbine and fan blade applications. For this study, the inclusion of negative viscous damping is used in order to approximate destabilizing aerodynamic forces. An exact analysis is conducted to determine the stability of this autonomous system. Results show that energy losses from the displacement-dependent dry friction damper are large enough to achieve local and even global stability under certain conditions.

Optimization on hysteresis dynamic model of metal rubber material based on dry friction damping term

2021 ◽  
pp. 095440622110197
Author(s):  
Hailong Fu ◽  
Yiwen Tao ◽  
Yue Wang ◽  
Longqing Zou ◽  
Yiqi Mao
Keyword(s):  
Parameter Identification ◽  
Dynamic Model ◽  
Dry Friction ◽  
Vibration Isolation ◽  
Material Structure ◽  
Damping Term ◽  
Friction Damping ◽  
Element Analysis ◽  
Metal Rubber ◽  
Dry Friction Damping

As one kind of porous elastic metal material, metal rubber is used in vibration isolation widely due to its better damping characteristic. During loading and unloading, the elastoplastic deformation and damping characteristics of this material are usually described by constructing its dynamic model. Although traditional models can describe the hysteresis performance, the accurate parameter identification of material structure under different preparation conductions is limited due to its complex expression or equivalent math form. In this paper, a dynamic hysteresis model is optimized through adding a dry friction damping term based on the micro-element analysis theory and analysis method of material mesoscopic structure. The relation among the manufacture technic, size of metal wire and vibration parameters were established, which accurately describes hysteresis characteristic of metal rubber by dry friction when the metal wires are in the state of slipping contact. The result is verified by the harmonic vibration experiment that the model has good adaptability and convenience, especially can improve the accuracy and convenience of parameter identification on the forming materials of metal rubber.

Study of Characteristics of Dry Friction Damping.

1985 ◽  
Author(s):  
A. V. Srinivasan ◽  
B. N. Cassenti ◽  
D. G. Cutts
Keyword(s):  
Dry Friction ◽  
Friction Damping ◽  
Dry Friction Damping

Engine Mount Optimization for Vibration Isolation in Motorcycles

2006 ◽  
Author(s):  
Sudhir Kaul ◽  
Anoop K. Dhingra ◽  
Timothy G. Hunter
Keyword(s):  
Optimization Problem ◽  
Vibration Isolation ◽  
Total Force ◽  
Engine Mounts ◽  
The Road ◽  
Design Variables ◽  
Swing Arm ◽  
Engine Mount ◽  
Six Degree Of Freedom

This paper presents a comprehensive model to capture the dynamics of a motorcycle system in order to evaluate the quality of vibration isolation. The two main structural components in the motorcycle assembly - the frame and the swing-arm - are modeled using reduced order finite element models; the power-train assembly is modeled as a six degree-of-freedom (DOF) rigid body connected to the frame through the engine mounts and to the swing-arm through a shaft assembly. The engine mounts are modeled as tri-axial spring-damper systems. Models of the front-end assembly as well as front and rear tires are also included in the overall model. The complete vehicle model is used to solve the engine mount optimization problem so as to minimize the total force transmitted to the frame while meeting packaging and other side constraints. The mount system parameters - stiffness, position and orientation vectors - are used as design variables for the optimization problem. The imposed loads include forces and moments due to engine imbalance as well as loads transmitted due to irregularities in the road surface through the tire patch.

Shape Optimization of Engine Mounts for Enhanced Vibration Isolation

2013 ◽  
Author(s):  
Fadi Alkhatib ◽  
Anoop K. Dhingra
Keyword(s):  
Finite Element Analysis ◽  
Optimization Problem ◽  
Vibration Isolation ◽  
Elastic Stiffness ◽  
Nonlinear Finite Element ◽  
Optimum Shape ◽  
Parametric Approach ◽  
Element Analysis ◽  
Engine Mounts ◽  
Engine Mount

In this article, a parametric approach is used to determine the optimum geometric shape of an engine mount in order to minimize the vibrations transmitted to and from the engine. The engine mount used is an elastomeric mount which is made of rubber. For proper vibration isolation, elastomeric mounts are designed such that they have the necessary elastic stiffness rate characteristics in all directions. An optimization problem is first solved to determine the optimum values of stiffness, orientation and location of the mount system such that vibrations transmitted are minimal. Besides determining the optimum mount stiffness values, knowing the optimum shape of the rubber mount is also vital. The shape of the mount is determined such that it meets the required stiffness of the mounting system obtained from the dynamic analysis. A nonlinear finite element analysis is used to determine the final optimum shape and stiffness of the mount.

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