Prediction of Suspension Fundamental Mode Frequency with Extraction of Dynamic Properties of Automotive Shock Absorbers and Tire

2001 ◽  
Author(s):  
Seung-Kab Jeong ◽  
Jin-Kawn Suh
Keyword(s):  
Fundamental Mode ◽  
Dynamic Properties ◽  
Mode Frequency ◽  
Shock Absorbers

Modal damping effects on the spatial distribution of anelastic damped vibration energy for a baseline cantilever structure

2011 ◽  
Vol 18 (10) ◽  
pp. 1575-1582 ◽  
Author(s):  
James E May ◽  
Craig Menzemer
Keyword(s):  
Fundamental Mode ◽  
Dynamic Properties ◽  
Flexible Structures ◽  
Longitudinal Axis ◽  
Vibration Energy ◽  
Modal Damping ◽  
Alternative Approach ◽  
Cantilever Structure ◽  
Control Concept ◽  
Spatial Displacements

Modal damping was conceived as a vibration control concept for potential application to a select set of long, flexible structures. This alternative approach was designed to exploit damping mechanisms inherent in the structures of interest by capitalizing on distinctive dynamic properties existing among vibration modes. The premise of modal damping is to transfer vibration energy from the fundamental mode where most vibration energy of civil structures of interest resides, to higher order modes where vibration impedance was shown to be more effective. A question was posed during its development concerning the subsequent risks to the structure. Spatial displacements, velocities and accelerations along the longitudinal axis will clearly be impacted and can readily be evaluated by simulation as required. The specific inquiry was directed at risks associated with redistribution of the damped vibration energy. In response, the distribution dynamics associated with the simple but ever-present anelastic damping mechanism was investigated and quantified. Furthermore, the analysis additionally offers support of the modal damping assertion by providing insight behind the increased dissipation effectiveness of the 2nd vibration mode over that of the fundamental mode.

Theoretical investigation of the fundamental mode frequency of A6 magnetron

2009 ◽  
Vol 105 (8) ◽  
pp. 083310 ◽  
Author(s):  
Yu-Wei Fan ◽  
Jing Liu ◽  
Hui-Huang Zhong ◽  
Ting Shu ◽  
Zhi-Qiang Li
Keyword(s):  
Theoretical Investigation ◽  
Fundamental Mode ◽  
Mode Frequency

Dynamic testing of shock absorbers under non-sinusoidal conditions

2002 ◽  
Vol 216 (5) ◽  
pp. 373-384 ◽  
Author(s):  
D Kowalski ◽  
M D Rao ◽  
J Blough ◽  
S Gruenberg
Keyword(s):  
Shock Absorber ◽  
Dynamic Testing ◽  
Dynamic Properties ◽  
Random Excitation ◽  
Amplitude Dependence ◽  
Ongoing Research ◽  
Shock Absorbers ◽  
Analysis Methodology ◽  
Road Data ◽  
Sine Sweep

This paper deals with the dynamic characterization of an automotive shock absorber, the continuation of an earlier work [1]. The objective of this ongoing research is to develop a testing and analysis methodology for obtaining dynamic properties of automotive shock absorbers for use in CAE-NVH low-to-mid-frequency chassis models. Stepped sine sweep excitation is currently used in industry to obtain shock absorber parameters along with their frequency and amplitude dependence. Sine-on-sine testing, which involves excitation using two different sine waves, has been done in this study to understand the effects of the presence of multiple sine waves on the estimated dynamic properties. In an effort to obtain all frequency dependent parameters simultaneously, different types of broadband random excitation have also been studied. Results are compared with stepped sine sweep tests. Additionally, actual road data measured on different road profiles have been used as input excitation to obtain the shock absorber parameters for broad frequency bands under realistic amplitude and frequency conditions. These results are compared with both simulated random excitation and stepped sine sweep test results.

scholarly journals Dynamic characterization and modeling of rubber shock absorbers: A comprehensive case study

2017 ◽  
Vol 37 (3) ◽  
pp. 509-518 ◽  
Author(s):  
H Ucar ◽  
I Basdogan
Keyword(s):  
Dynamic Properties ◽  
Viscoelastic Model ◽  
Constitutive Models ◽  
Material Model ◽  
Uniaxial Tensile ◽  
Primary Concern ◽  
Dynamic Characterization ◽  
Time Frequency ◽  
Shock Absorbers

Rubber or elastomeric materials are widely used for shock absorbers having elastic and viscous properties such as high inherent damping, deflection capacity, and energy storage. The dynamic properties of these components are of primary concern in designing rubber absorbers to reduce the shock loading given as well as the structure-borne noise transmissibility. Besides, the dynamic response of the mechanical systems, at where the rubber shock absorbers are used, is directly associated with the properties of the shock absorbers. In order to determine these properties of the rubber, mathematical models are created in terms of hyperelasticity and viscoelasticity. The hyperelastic and viscoelastic material models represent the nonlinear elastic and strain rate dependencies of the overall rubber behavior, respectively. Hyperelastic material model captures the material’s nonlinear elasticity with no-time dependence whereas viscoelastic model describes the material response which contains an elastic and viscous part depending on time, frequency, and temperature. This paper presents the dynamic characterization of rubber shock absorbers, having different shore hardness values, in terms of hyperelastic and viscoelastic constitutive models. The parameters of the constitutive models are determined from the uniaxial tensile and relaxation tests. These parameters are used for the numerical model of the rubber components and the accuracy of the characterization is presented by means of a numerical case study.

Characterization of Automotive Shock Absorbers Using Random Excitation

1995 ◽  
Vol 209 (4) ◽  
pp. 239-248 ◽  
Author(s):  
S Cafferty ◽  
K Worden ◽  
G Tomlinson
Keyword(s):  
Mathematical Model ◽  
Dynamic Properties ◽  
Test Procedure ◽  
Random Excitation ◽  
Fixed Frequency ◽  
Restoring Force ◽  
Shock Absorbers ◽  
The Mathematical Model ◽  
Clear Method

In a previous paper [see reference (4)], it was shown that the restoring force surface (RFS) procedure provides a direct and clear method for characterizing the dynamic properties of automotive shock absorbers or dampers. The procedure was based on repetitive harmonic testing of the absorbers at fixed frequency but with varying amplitude. The current paper describes how the surfaces can be obtained from tests using random excitation. The merits and demerits are discussed relative to the harmonic test procedure. It is shown that the random excitation approach offers a useful alternative but produces force surfaces which are corrupted by small stochastic components; an explanation of the distortion is given in terms of the mathematical model proposed in the previous paper. The implications for identification of shock absorbers are discussed

scholarly journals Dynamic Properties of Rubber-Type Shock Absorbers Subjected to Pounding Force.

2001 ◽  
pp. 219-234 ◽  
Author(s):  
Satoshi SHIMANOE ◽  
Kei-ichi HASEGAWA ◽  
Kazuhiko KAWASHIMA ◽  
Gaku SHOJI
Keyword(s):  
Dynamic Properties ◽  
Shock Absorbers

scholarly journals AGING, FATIGUE AND DURABILITY OF RUBBER VIBRATION ISOLATION ELEMENTS

2017 ◽  
Vol 3 ◽  
pp. 269
Author(s):  
Svetlana Polukoshko ◽  
Andris Martinovs ◽  
Svetlana Sokolova
Keyword(s):  
Vibration Isolation ◽  
Dynamic Properties ◽  
High Stress ◽  
Machine Building ◽  
Thin Layers ◽  
Shock Absorbers ◽  
Elastomeric Materials ◽  
High Fatigue ◽  
Long Time ◽  
Compensating Devices

This paper deal with shock and vibration insulators, which usually are performed from the elastomeric (rubber-like) materials. Elastomeric materials give many engineering advantages due to their capability of absorbing input energy much better than engineering materials, high elasticity, good dynamic properties, low volume compressibility, a linear relationship between stress and strain up to strain of 15% ÷ 20%, resistance to aggressive environmental factors. Elastomeric materials are widely used in machine building, shipbuilding, civil engineering, aviation and aerospace as compensation devices, vibration dampers, shock absorbers. Laminated elastomers, consisting of interleaved thin layers of elastomer and rigid reinforcing layers are also successfully used as bearing, joints, dampers, compensating devices, shock-absorbers. Such structures have many advantages: ability to endure high stress (>200 MPa), ease of maintenance, non- necessity for lubrication, vibration and noise reduction, ability to work in a very dirty, dusty, abrasive environment. The disadvantage of elastomeric material are aging, i.e. changing its properties over time. In this paper the influence of aging of elastomeric materials on the damping properties of shock absorbers is considered based on the mechanical models of elastomers - Maxwell and Burgers modes. Fatigue endurance, i.e. the ability to withstand mechanical actions for a long time is studied based on experiments on dynamic shear with laminated rubber-metal structures. The experiments show that such structures have a very high fatigue life - up to 100 million cycles.

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