scholarly journals Finite Element Analysis for Vibration Properties of Panels in Car Bodies Having Viscoelastic Layer (3rd Report, Investigation of Bead Shapes which can Concenterate Distribution of Dissipated Energy on Local Area in the Panels)

2004 ◽  
Vol 70 (699) ◽  
pp. 3062-3069 ◽  
Author(s):  
Takao YAMAGUCHI ◽  
Yasunori TAKEMAE ◽  
Yoshio KUROSAWA ◽  
Shuuji MATSUMURA
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Local Area ◽  
Dissipated Energy ◽  
Viscoelastic Layer ◽  
Element Analysis ◽  
Vibration Properties

Dynamic Analysis to Evaluate Viscoelastic Passive Damping Augmentation for the Space Shuttle Remote Manipulator System

1992 ◽  
Vol 114 (3) ◽  
pp. 468-475 ◽  
Author(s):  
Thomas E. Alberts ◽  
Houchun Xia ◽  
Yung Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Analysis ◽  
Active Control ◽  
Space Shuttle ◽  
Viscoelastic Layer ◽  
Passive Damping ◽  
Element Analysis ◽  
Joint Flexibility ◽  
Damping Treatments

This paper presents a NASTRAN finite element analysis for evaluation of the effectiveness of viscoelastic damping treatments as passive controls for large flexible space manipulators. The passive damping could be used alone or as an augmentation to active control. Perhaps the best existing example of a practical flexible manipulator is the space shuttle Remote Manipulator System (RMS). The authors use the RMS as an example for this investigation, subjecting it to a detailed dynamic analysis which can be used to evaluate the critical modes for control and to distinguish the modes which are good candidates for active control from those which are well suited for passive control. Modal potential energy analysis (MPE) is used to examine the modal energy distribution in each structural member of the complex flexible chained system. The results indicate that the most dominant contributors to end-point oscillations fall into two categories. These include very low frequency modes due to joint flexibility and higher frequency modes due to bending in the booms. Significant end-point motions result from each category, but the most significant motions are associated with joint flexibility. Finally, a finite element analysis is performed to evaluate the effectiveness of constrained viscoelastic layer damping treatments for passive vibration control. Passive damping augmentation is introduced through the use of a constrained viscoelastic layer damping treatment applied to the surface of the manipulator’s flexible booms. It is shown that even the joint compliance dominated modes can be damped to some degree through appropriate design of the treatment.

Finite Element Analysis of Structural Safety of a Steel TV Tower

2011 ◽  
Vol 421 ◽  
pp. 217-224
Author(s):  
Yi Sun ◽  
Xiang Dong Shu ◽  
Wen Qi Yang ◽  
Qiao Rong Zhao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Security Analysis ◽  
Local Area ◽  
Structural Safety ◽  
Element Analysis ◽  
Corrosion Depth ◽  
The Finite Element Analysis ◽  
Tower Structure ◽  
Terrain Effect

The steel truss TV tower structure, the height is 183.1 m, which is built in 1970, was corroded obviously. In order to ensure its structural safety, completely detection and security analysis have been implement. The tower is located in the top of the ridge, and hilly terrain effect was included in the whole structure analysis. Finite element analysis of bar elements was done to inspect whole structure safety. The results show, most of the members were safe, but with the height of 120 m, stress ratio of columns and diagonal braces is large than 1, and can’t meet the requirement of current codes. Additional solid finite element analysis of joint zone shows that, stress in very local area of connection plates reached to the yield stress, but they were safe enough after plastic stress redistribution. According to the results of corrosion depth test, the finite element analysis of structure after corrosion is done. After corrosion, the bearing capacity of columns almost reaches the limitation. The increase of any load or corrosion depth may lead to the failure of columns.

Experimental and Finite Element Analysis of Stand-Off Layer Damping Treatments for Beams

2007 ◽  
Author(s):  
Jessica M. H. Yellin ◽  
I. Y. Shen ◽  
Per G. Reinhall
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Frequency Response ◽  
Viscoelastic Layer ◽  
Constrained Layer Damping ◽  
Response Functions ◽  
Element Analysis ◽  
Frequency Response Functions ◽  
Damping Treatments ◽  
Passive Constrained Layer Damping

Passive stand-off layer (PSOL) and slotted stand-off layer (SSOL) damping treatments are presently being implemented in many commercial and defense designs. In a PSOL damping treatment, a stand-off or spacer layer is added to a conventional passive constrained layer damping treatment. In an SSOL damping treatment, slots are included in the stand-off layer. A set of experiments using PSOL and SSOL beams in which the geometric properties of the stand-off layer were varied was conducted to analyze the contribution of the stand-off layer to the overall system damping. This set of experiments measured the frequency response functions for a series of beams in which the total slotted area of the stand-off layer was held constant while the number of slots in the stand-off layer was increased for a constant stand-off layer material. Finite element analysis models were developed in ANSYS to compare the predicted frequency response functions with the experimentally measured frequency response functions for the beams treated with PSOL and SSOL damping treatments. In these beams, the bonding layers used to fabricate these treatments were found to have a measurable and significant effect on the frequency response of the structure. The finite element model presented here thus included an epoxy layer between the base beam and the stand-off layer, a contact cement layer between the stand-off layer and the viscoelastic layer, and a method for modeling delamination.

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