scholarly journals Topology Optimization of Constrained Layer Damping on Plates Using Method of Moving Asymptote (MMA) Approach

2011 ◽  
Vol 18 (1-2) ◽  
pp. 221-244 ◽  
Author(s):  
Zheng Ling ◽  
Xie Ronglu ◽  
Wang Yi ◽  
Adel El-Sabbagh
Keyword(s):  
Topology Optimization ◽  
Energy Dissipation ◽  
Design Variable ◽  
Optimization Design ◽  
Damping Ratio ◽  
Design Tool ◽  
Optimization Approach ◽  
Constrained Layer Damping ◽  
Modal Damping Ratio ◽  
Modal Damping

Damping treatments have been extensively used as a powerful means to damp out structural resonant vibrations. Usually, damping materials are fully covered on the surface of plates. The drawbacks of this conventional treatment are also obvious due to an added mass and excess material consumption. Therefore, it is not always economical and effective from an optimization design view. In this paper, a topology optimization approach is presented to maximize the modal damping ratio of the plate with constrained layer damping treatment. The governing equation of motion of the plate is derived on the basis of energy approach. A finite element model to describe dynamic performances of the plate is developed and used along with an optimization algorithm in order to determine the optimal topologies of constrained layer damping layout on the plate. The damping of visco-elastic layer is modeled by the complex modulus formula. Considering the vibration and energy dissipation mode of the plate with constrained layer damping treatment, damping material density and volume factor are considered as design variable and constraint respectively. Meantime, the modal damping ratio of the plate is assigned as the objective function in the topology optimization approach. The sensitivity of modal damping ratio to design variable is further derived and Method of Moving Asymptote (MMA) is adopted to search the optimized topologies of constrained layer damping layout on the plate. Numerical examples are used to demonstrate the effectiveness of the proposed topology optimization approach. The results show that vibration energy dissipation of the plates can be enhanced by the optimal constrained layer damping layout. This optimal technology can be further extended to vibration attenuation of sandwich cylindrical shells which constitute the major building block of many critical structures such as cabins of aircrafts, hulls of submarines and bodies of rockets and missiles as an invaluable design tool.

Topology Optimization for Constrained Layer Damping Plates Using Evolutionary Structural Optimization Method

2014 ◽  
Vol 894 ◽  
pp. 158-162 ◽  
Author(s):  
Bing Qin Wang ◽  
Bing Li Wang ◽  
Zhi Yuan Huang
Keyword(s):  
Topology Optimization ◽  
Energy Dissipation ◽  
Structural Optimization ◽  
Design Variable ◽  
Loss Factor ◽  
Optimization Approach ◽  
Constrained Layer Damping ◽  
Modal Strain Energy ◽  
Evolutionary Structural Optimization ◽  
Constrained Damping

The evolutionary structural optimization (ESO) is used to optimize constrained damping layer structure. Considering the vibration and energy dissipation mode of the plate with constrained layer damping treatment, the elements of constrained damping layers and modal loss factor are considered as design variable and objective function, while damping material consumption is considered as a constraint. The sensitivity of modal loss factor to design variable is further derived using modal strain energy analysis method. Numerical example is used to demonstrate the effectiveness of the proposed topology optimization approach. The results show that vibration energy dissipation of the plates can be enhanced by the optimal constrained layer damping layout.

Multi-material topology optimization for improvement of modal damping ratio

2016 ◽  
Vol 2016 (0) ◽  
pp. 447
Author(s):  
Youhei NAKANO ◽  
Akihiro TAKEZAWA ◽  
Kohya Nakagawa ◽  
Takashi Yamamoto ◽  
Mitsuru Kitamura
Keyword(s):  
Topology Optimization ◽  
Damping Ratio ◽  
Modal Damping Ratio ◽  
Modal Damping

Investigation of modal damping ratios for stay cables based on stochastic subspace identification with ambient vibration measurements

2019 ◽  
Vol 22 (16) ◽  
pp. 3444-3460 ◽  
Author(s):  
Chien-Chou Chen ◽  
Wen-Hwa Wu ◽  
Szu-Ting Yu ◽  
Gwolong Lai
Keyword(s):  
Energy Dissipation ◽  
Damping Ratio ◽  
Ambient Vibration ◽  
Subspace Identification ◽  
Stochastic Subspace Identification ◽  
Modal Damping Ratio ◽  
Stay Cables ◽  
Modal Damping ◽  
Ambient Vibration Measurements ◽  
Cable Stayed Bridges

The stability assessment of stay cables based on the damping ratios of lower cable modes has attracted a large amount of research efforts. An accurate determination of those modal damping ratios is consequently required for the analysis or health monitoring of cable-stayed bridges. The aim of this study was to explore the challenge in accurately identifying the modal damping ratios of stay cable. The ambient vibration measurements collected from the stay cables of four cable-stayed bridges are investigated to cover different characteristics. A recently developed methodology based on stochastic subspace identification is adopted to determine the modal damping ratios of the cable. With the identified modal damping ratios for the stay cables of four bridges, comparison is made to examine the range of cable damping in different cable-stayed bridges and discuss the effects of several influence factors. It is found that the modal damping ratios for the stay cables of investigated bridges typically fall between 0% and 0.7%, close to the range from 0.05% to 0.5% reported by Post-Tensioning Institute. Moreover, it is also discovered that the modal damping ratio of the cable would decrease with increasing cable length if the energy dissipation mechanism of the cable principally comes from the anchorage device. In the cases where the middle free length section of the cable is filled with effective grouting materials, the modal damping ratio of the cable is not necessarily correlated with the cable length. Finally, the obtained results also indicate that the grouting material filled in the middle free length section of the cable defines the primary contribution to energy dissipation ranked by a descending order of ceresine wax, flexible polymer-modified cement and polyurethane foam.

Synthesis and Numerical Analysis of Compliant devices – A Topology Optimization Approach for Mechanisms and Robotic Systems

2021 ◽  
Author(s):  
Premanand Sathyanarayanamurthi ◽  
ARUNKUMAR GOPAL
Keyword(s):  
Topology Optimization ◽  
Optimization Design ◽  
Rectangular Domain ◽  
Dynamic State ◽  
Optimization Approach ◽  
Design And Development ◽  
Design Synthesis ◽  
Final Destination ◽  
Prototype Development ◽  
External Forces

Abstract The Topology Optimization design invariably shall be used in various applications like Aerojet designs, Aircraft Engineering designs and innovative systems for improving the efficiency of structure. The paper emphasizes more on general Topology Optimization design for a rectangular domain. The domain numerically analyzed with defined geometry setting and defined boundary conditions for finding the Stress and displacement. In this Topology Optimization Design synthesis, the result is suitable volume and mass reduction in the Aerojet application parts which further can be taken for Prototype development in 3D printing and experimentally test with safety characteristics and compares Objective functions chosen for design and development. The design can be used for other various automotive and aerospace devices based on deformation level and application of external forces. The Final destination of this design and development ends with passing Fatigue Endurance test cycle test pass condition in Aerojet and automotive vehicles in static and dynamic state.

Topology Optimization of Three-Dimensional Woven Materials Using a Ground Structure Design Variable Representation

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Seung-Hyun Ha ◽  
Hak Yong Lee ◽  
Kevin J. Hemker ◽  
James K. Guest
Keyword(s):  
Topology Optimization ◽  
Design Variable ◽  
Three Dimensional ◽  
Structure Design ◽  
Optimization Approach ◽  
Ground Structure ◽  
Flow Equations ◽  
Combined Algorithm ◽  
Variable Representation ◽  
3D Weaving

Three-dimensional (3D) weaving has recently arisen as viable means for manufacturing metallic, architected microlattices. Herein, we describe a topology optimization approach for designing the architecture of such 3D woven lattices. A ground structure design variable representation is combined with linear manufacturing constraints and a projection mapping to realize lattices that satisfy the rather restrictive topological constraints associated with 3D weaving. The approach is demonstrated in the context of inverse homogenization to design lattices with maximized fluid permeability. Stokes flow equations with no-slip conditions governing unit cell flow fields are interpolated using the Darcy–Stokes finite element model, leveraging existing work in the topology optimization of fluids. The combined algorithm is demonstrated to design manufacturable lattices with maximized permeability whose properties have been experimentally measured in other published work.

Modal damping ratio analysis of dynamical system with non-stationary responses

2016 ◽  
Vol 59 ◽  
pp. 138-146 ◽  
Author(s):  
Da Tang ◽  
Ran Ju ◽  
Qianjin Yue ◽  
Shisheng Wang
Keyword(s):  
Dynamical System ◽  
Damping Ratio ◽  
Ratio Analysis ◽  
Modal Damping Ratio ◽  
Modal Damping

scholarly journals Coupling of Flexural and Longitudinal Damped Vibration in a Two-Layered Beam

1998 ◽  
Vol 5 (5-6) ◽  
pp. 337-341
Author(s):  
F. Pourroy ◽  
S. Shakhesi ◽  
P. Trompette
Keyword(s):  
Damping Ratio ◽  
Modal Damping Ratio ◽  
Modal Damping ◽  
Resonance Frequencies ◽  
Layered Beam ◽  
Flexural Vibrations

In dynamics, the effect of varying the constitutive materials’ thickness of a two-layered beam is investigated. Resonance frequencies and damping variations are determined. It is shown that for specific thicknesses the coupling of longitudinal and flexural vibrations influences the global modal damping ratio significantly.

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