Smoothing, Interpolating, and Modeling Complex Modulus Data for Viscoelastic Damping Materials, Including a New Approach to Temperature Shift Functions

2004 ◽  
Author(s):  
Lynn C. Rogers ◽  
Bryce Fowler
Keyword(s):  
Complex Modulus ◽  
Temperature Shift ◽  
Viscoelastic Damping ◽  
New Approach ◽  
Damping Materials

High Frequency Vibration Analysis of Automotive Body Panels with Damping Materials

2010 ◽  
Vol 36 ◽  
pp. 293-296
Author(s):  
Yoshio Kurosawa ◽  
Takao Yamaguchi
Keyword(s):  
High Frequency ◽  
Large Scale ◽  
The Body ◽  
Viscoelastic Damping ◽  
Fe Model ◽  
Test Results ◽  
Automotive Body ◽  
Modal Damping ◽  
Practical Tool ◽  
Damping Materials

We have developed a technique for estimating vibrations of an automotive body structures with viscoelastic damping materials using large-scale finite element (FE) model, which will enable us to grasp and to reduce high-frequency road noise（200～500Hz）. In the new technique, first order solutions for modal loss factors are derived applying asymptotic method. This method saves calculation time to estimate modal damping as a practical tool in the design stages of the body structures. Frequency responses were calculated using this technique and the results almost agreed with the test results. This technique can show the effect of the viscoelastic damping materials on the automotive body panels, and it enables the more efficient layout of the viscoelastic damping materials. Further, we clarified damping properties of the automotive body structures under coupled vibration between frames and panels with the viscoelastic damping materials.

High Frequency Vibration Analysis of Automotive Bodies With Panels That Have Attached Viscoelastic Layers

2003 ◽  
Author(s):  
Yoshio Kurosawa ◽  
Hideki Enomoto ◽  
Shuji Matsumura ◽  
Takao Yamaguchi
Keyword(s):  
High Frequency ◽  
Large Scale ◽  
The Body ◽  
Viscoelastic Damping ◽  
Fe Model ◽  
Automotive Body ◽  
Modal Damping ◽  
Practical Tool ◽  
Damping Materials ◽  
Viscoelastic Layers

A technique has been developed for estimating vibrations of an automotive body structures with viscoelastic damping materials using large-scale finite element (FE) model, which will enable us to grasp and to reduce high-frequency road noise (200∼500Hz). In the new technique, first order solutions for modal loss factors are derived applying asymptotic method. This method saves calculation time to estimate modal damping as a practical tool in the design stages of the body structures. Frequency responses were calculated using this technique and the results almost agreed with the test results. This technique can show the effect of the viscoelastic damping materials on the automotive body panels, and it enables the more efficient layout of the viscoelastic damping materials. Further, we clarified damping properties of the automotive body structures under coupled vibration between frames and panels with the viscoelastic damping materials.

scholarly journals Vibroacoustical Analysis of Multiple-Layered Structures with Viscoelastic Damping Cores

2013 ◽  
Vol 2013 ◽  
pp. 1-13
Author(s):  
Fei Lin ◽  
Mohan D. Rao
Keyword(s):  
Vibration Analysis ◽  
Complex Geometry ◽  
Nonlinear Behavior ◽  
Structural Vibration ◽  
Viscoelastic Damping ◽  
Beam Structure ◽  
Arbitrary Boundary ◽  
Damping Materials ◽  
Damping Model ◽  
Element Method

This paper presents a modeling technique to study the vibroacoustics of multiple-layered viscoelastic laminated beams using the Biot damping model. In this work, a complete simulation procedure for studying the structural acoustics of the system using a hybrid numerical model is presented. The boundary element method (BEM) was used to model the acoustical cavity, whereas the finite element method (FEM) was the basis for vibration analysis of the multiple-layered beam structure. Through the proposed procedure, the analysis can easily be extended to another complex geometry with arbitrary boundary conditions. The nonlinear behavior of viscoelastic damping materials was represented by the Biot damping model taking into account the effects of frequency, temperature, and different damping materials for individual layers. The curve-fitting procedure used to obtain the Biot constants for different damping materials for each temperature is explained. The results from structural vibration analysis for selected beams agree with published closed-form results, and results for the radiated noise for a sample beam structure obtained using a commercial BEM software are compared with the acoustical results of the same beam by using the Biot damping model.

Study on the Damping Properties of Multi-Layered Gradient Materials Based on Organic Hybrids

2012 ◽  
Vol 268-270 ◽  
pp. 119-122
Author(s):  
Xin Bo Ding ◽  
Tao Liu ◽  
Bao Cheng Fu ◽  
Jian Han
Keyword(s):  
Hybrid Materials ◽  
High Performance ◽  
Damping Properties ◽  
Transition Range ◽  
New Approach ◽  
Gradient Materials ◽  
Number Of Layers ◽  
Damping Material ◽  
Damping Materials ◽  
Two Peaks

In this paper, the multi-layered gradient materials consisting of polarized polymers and small molecules were prepared and the damping properties were studied by DMA. The predicted and experimental results showed that, it was possible to obtain damping material with broad efficient damping range by two-layered hybrid materials, the value in the middle of two peaks could be improved by increasing the number of layers of the multi-layered hybrids and there was a higher minimum value. On the other hand, with increased number of the layers of the multi-layered hybrid materials, the temperature dependence of could be improved. For five-layered gradient materials, it was almost rectangular transition range with values for the area under the linear curve. Thus, it would be feasible in theory and experiment to broaden the efficient damping range by multi-layered gradient materials based on organic hybrids, which provided a new approach and solid basis for developing high performance damping materials with a broad and high damping range.

Research the Influence of Curved Shape on the Multilayer Bellows

2013 ◽  
Vol 303-306 ◽  
pp. 2740-2743 ◽  
Author(s):  
Dong Hong Si ◽  
Yong Gang Liu ◽  
Wei Ma
Keyword(s):  
Finite Element ◽  
Energy Distribution ◽  
Loss Factor ◽  
Strain Energy ◽  
Structural Parameters ◽  
Viscoelastic Damping ◽  
Finite Element Models ◽  
Small Wave ◽  
Thin Walled ◽  
Damping Materials

As a cylindrical thin-walled container, multilayer bellows has greater bit shift compensation, vibration and noise reduction capabilities while the appropriate metal and viscoelastic damping materials are adopted. Finite element models are adopted to analyze the loss factor of multilayer bellows in ANSYS. The strain energy distribution of Multilayer bellows and viscoelsticity layer are given. According to the strain energy, the influence of structural parameters on the loss factor is studied. The results show that the loss factor can be improved by employing the curved shape with big wave height, small wall thickness, small wave pitch and diameter of bellows.

Analysis and Prediction of Damping Properties of Multi-Layered Organic Hybrid Materials Consisting of Polarized Polymers and Small Molecules

2012 ◽  
Vol 535-537 ◽  
pp. 1197-1200
Author(s):  
Xin Bo Ding ◽  
Tao Liu ◽  
Yan Hui Zhang ◽  
Jian Han
Keyword(s):  
Temperature Dependence ◽  
Small Molecules ◽  
Hybrid Materials ◽  
Theoretical Study ◽  
Correspondence Principle ◽  
Damping Properties ◽  
Transition Range ◽  
New Approach ◽  
Organic Hybrid ◽  
Damping Materials

A theoretical study on damping properties of multi-layered hybrid materials was presented with the aim to obtain good damping materials with a broad and high damping range. The value of the multi-layered organic hybrid materials consisting of polarized polymers and small molecules was evaluated via the correspondence principle. Similarly, the damping properties of the multi-layered organic hybrid materials were predicted according to our previous work. With increasing the number of the layers of multi-layered hybrids, the temperature dependence of could be improved and it was almost rectangular transition range with values for the area under the linear curve. Therefore, it could be considered to be a new approach to improve the temperature dependence of the damping materials and obtain good damping materials with a broad and high damping range.

Sign in / Sign up

Export Citation Format

Share Document