Topology Optimization of Constrained Damping Layer Treatments

2002 ◽  
Author(s):  
Arnold Lumsdaine
Keyword(s):  
Topology Optimization ◽  
Loss Factor ◽  
Elastic Beam ◽  
Forced Response ◽  
Optimization Process ◽  
Programming Algorithm ◽  
Optimal Topology ◽  
Modal Strain Energy ◽  
Constrained Damping ◽  
Half Power

The aim of this research is to determine the optimal shape of a constrained viscoelastic damping layer on an elastic beam by means of topology optimization. The optimization objective is to maximize the system loss factor for the first resonance frequency of the base beam. All previous optimal design studies on viscoelastic lamina have been size or shape optimization studies, assuming a certain topology for the damping treatment. In this study, this assumption is relaxed, allowing an optimal topology to emerge. The loss factor is computed using the Modal Strain Energy method in the optimization process. Loss factor results are validated by using the half-power bandwidth method, which requires obtaining the forced response of the structure. The ABAQUS finite element code is used to model the structure with two-dimensional continuum elements. The optimization code uses a Sequential Quadratic Programming algorithm. Results show that significant improvements in damping performance, on the order of 100% to 300%, are obtained by optimizing the constrained damping layer topology. A novel topology for the constraining layer emerges through the optimization process.

Design of Constrained Layer Damping Topologies

Aerospace ◽  
2003 ◽  
Author(s):  
Arnold Lumsdaine ◽  
Rohan Pai
Keyword(s):  
Loss Factor ◽  
Vibration Damping ◽  
Forced Response ◽  
Programming Algorithm ◽  
Constrained Layer Damping ◽  
Modal Strain Energy ◽  
Modal Strain Energy Method ◽  
Beam Thickness ◽  
Constrained Damping ◽  
Half Power

The aim of this research is to determine the optimal topologies for viscoelastic lamina used for vibration damping. The optimization objective is to maximize the system loss factor for the first resonance frequency of a base structure. Previous optimal design studies examining viscoelastic lamina have been size or shape optimization studies, assuming a certain topology for the damping treatment. In this study, the topology is optimized to maximize vibration damping levels. The loss factor is computed using the Modal Strain Energy method in the optimization process. For the initial and optimal topologies, the loss factor results are validated by using the half-power bandwidth method, which requires obtaining the forced response of the structure. The ABAQUS finite element code is used to model the structure with two-dimensional, plane stress, continuum elements. The optimization code uses a Sequential Quadratic Programming algorithm. This study extends the results of a previous study by Lumsdaine (2002) by examining the effects of a number of parameters on the optimal damping levels and the optimal topologies. The parameters examined include the total elastic and viscoelastic material fractions and the base beam thickness. Results show that significant improvements in damping performance, over 300% in some cases, are obtained by optimizing the constrained damping layer topology.

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.

Thermo-Structural Coupled Topology Optimization of Micro-Capacitive Accelerometer

2012 ◽  
Vol 433-440 ◽  
pp. 3080-3085 ◽  
Author(s):  
Huan Yuan Chen ◽  
Yong Jun Xie ◽  
Dong Song Yan ◽  
Hao Liu ◽  
Jing Ming Li
Keyword(s):  
Topology Optimization ◽  
Elastic Beam ◽  
Optimal Topology ◽  
Beam Structure ◽  
Innovative Design ◽  
Maximum Deformation ◽  
Structure Topology ◽  
Capacitive Accelerometer ◽  
Limit Value ◽  
Moving Asymptotes

In order to enhance the working performance of micro-capacitive accelerometer in high temperature environment, the structure topology optimization of a micro-capacitive accelerometer is proposed. After the study of thermo-structural coupled governing equations and sensitivity analysis, the mass-block and elastic-beam structure of comb micro-capacitive accelerometer topology optimization model is established. Then the optimal topology forms of mass-block and elastic-beam structure are obtained with the MMA (method of moving asymptotes) method. At last, the calculating results indicate that the maximum deformation at acceleration detection direction is only 22nm at the operating temperature range of 0~300°C, which less than the maximum deformation of the limit value (25nm), and provides a reliable way for innovative design of micro-capacitive accelerometer.

Improvement of a topological level-set approach to find optimal topology by considering body forces

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Meisam Takalloozadeh ◽  
Gil Ho Yoon
Keyword(s):  
Topology Optimization ◽  
Level Set ◽  
Thermal Loading ◽  
Topological Derivative ◽  
Optimization Process ◽  
Optimal Topology ◽  
Content Type ◽  
Body Forces ◽  
Applied Forces ◽  
Level Set Approach

Purpose Body forces are always applied to structures in the form of the weight of materials. In some cases, they can be neglected in comparison with other applied forces. Nevertheless, there is a wide range of structures in civil and mechanical engineering in which weight or other types of body forces are the main portions of the applied loads. The optimal topology of these structures is investigated in this study. Design/methodology/approach Topology optimization plays an increasingly important role in structural design. In this study, the topological derivative under body forces is used in a level-set-based topology optimization method. Instability during the optimization process is addressed, and a heuristic solution is proposed to overcome the challenge. Moreover, body forces in combination with thermal loading are investigated in this study. Findings Body forces are design-dependent loads that usually add complexity to the optimization process. Some problems have already been addressed in density-based topology optimization methods. In the present study, the body forces in a topological level-set approach are investigated. This paper finds that the used topological derivative is a flat field that causes some instabilities in the optimization process. The main novelty of this study is a technique used to overcome this challenge by using a weighted combination. Originality/value There is a lack of studies on level-set approaches that account for design-dependent body forces and the proposed method helps to understand the challenges posed in such methods. A powerful level-set-based approach is used for this purpose. Several examples are provided to illustrate the efficiency of this method. Moreover, the results show the effect of body forces and thermal loading on the optimal layout of the structures.

scholarly journals Microstructural Topology Optimization of Constrained Layer Damping on Plates for Maximum Modal Loss Factor of Macrostructures

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Zhanpeng Fang ◽  
Lei Yao ◽  
Shuxia Tian ◽  
Junjian Hou
Keyword(s):  
Topology Optimization ◽  
Loss Factor ◽  
Strain Energy ◽  
Design Method ◽  
Optimization Method ◽  
Constrained Layer Damping ◽  
Viscoelastic Materials ◽  
Modal Strain Energy ◽  
Design Variables ◽  
Microstructural Topology Optimization

This paper presents microstructural topology optimization of viscoelastic materials for the plates with constrained layer damping (CLD) treatments. The design objective is to maximize modal loss factor of macrostructures, which is obtained by using the Modal Strain Energy (MSE) method. The microstructure of the viscoelastic damping layer is composed of 3D periodic unit cells. The effective elastic properties of the unit cell are obtained through the strain energy-based method. The density-based topology optimization is adopted to find optimal microstructures of viscoelastic materials. The design sensitivities of modal loss factor with respect to the design variables are analyzed and the design variables are updated by Method of Moving Asymptotes (MMA). Numerical examples are given to demonstrate the validity of the proposed optimization method. The effectiveness of the optimal design method is illustrated by comparing a solid and an optimized cellular viscoelastic material as applied to the plates with CLD treatments.

Structural Topology Design Considering Reliability

2005 ◽  
Vol 297-300 ◽  
pp. 1901-1906 ◽  
Author(s):  
Seung Jae Min ◽  
Seung Hyun Bang
Keyword(s):  
Topology Optimization ◽  
Design Optimization ◽  
Optimization Problem ◽  
Performance Measure ◽  
Topology Design ◽  
Optimization Process ◽  
Programming Algorithm ◽  
Probabilistic Design ◽  
Most Probable Point ◽  
Design Variables

In the design optimization process design variables are selected in the deterministic way though those have uncertainties in nature. To consider variances in design variables reliability-based design optimization problem is formulated by introducing the probability distribution function. The concept of reliability has been applied to the topology optimization based on a reliability index approach or a performance measure approach. Since these approaches, called double-loop singlevariable approach, requires the nested optimization problem to obtain the most probable point in the probabilistic design domain, the time for the entire process makes the practical use infeasible. In this work, new reliability-based topology optimization method is proposed by utilizing single-loop singlevariable approach, which approximates searching the most probable point analytically, to reduce the time cost and dealing with several constraints to handle practical design requirements. The density method in topology optimization including SLP (Sequential Linear Programming) algorithm is implemented with object-oriented programming. To examine uncertainties in the topology design of a structure, the modulus of elasticity of the material and applied loadings are considered as probabilistic design variables. The results of a design example show that the proposed method provides efficiency curtailing the time for the optimization process and accuracy satisfying the specified reliability.

scholarly journals On the Region for the Application of Passive Damping Treatment and Loss Factor Enhancement

2019 ◽  
Vol 24 (4) ◽  
pp. 693-700
Author(s):  
Thomas K. Joseph ◽  
K. Renji ◽  
Kartik Venkatraman
Keyword(s):  
Energy Distribution ◽  
Viscoelastic Material ◽  
Loss Factor ◽  
Strain Energy ◽  
Significant Loss ◽  
Efficient Design ◽  
Modal Strain Energy ◽  
Damping Material ◽  
Modes Of Vibration ◽  
Constrained Damping

The loss factor of a structure is significantly improved by using constrained damping treatment. For a mass efficient design, the damping material is to be applied at suitable locations. The studies reported in literature use the modal strain energy distribution in the viscoelastic material or the strain energy distribution in the base structure as tools to arrive at these suitable locations for the damping treatment. It is shown here that the regions identified through the above criteria need not be suitable for certain bending modes of vibration. A new approach is proposed in which the strain in the viscoelastic material and the angle of flexure are shown to be more reliable in arriving at the locations for the damping treatment. Providing damping layers at identified locations using these parameters results in significant loss factors with minimal added mass.

Research on Topology Optimization Method for Continuum Structure under Geometric Constraints

2011 ◽  
Vol 291-294 ◽  
pp. 1589-1592
Author(s):  
Li Ren ◽  
Rui Yang ◽  
Wen Xiao Zhang
Keyword(s):  
Topology Optimization ◽  
Shape Optimization ◽  
Objective Function ◽  
Optimization Technique ◽  
Optimization Method ◽  
Geometric Constraints ◽  
Optimization Process ◽  
Optimal Topology ◽  
Penalty Function Method ◽  
Continuum Structure

A new topology optimization model with holes’ geometric constraints for continuum structure is presented. It is solved by an evolutionary optimization method based on interval relaxation, in which the problem is divided into two subproblems of topology optimization process and size/shape optimization process. The optimal topology of structure can be found gradually by introducing interval relaxation factor to adjust holes’ size constraints, delete noneffective holes and by generating new holes based on the sensitivity analysis of objective function. Interior penalty-function method is employed as an optimization technique for the size/shape optimization of the structure corresponding to the topology. When the holes’ size bounds are the actual values, the optimal solution is the smallest objective function structure in the various topologies. Thus realizes the holes’ geometric size and location design, topology design and layout design together. The optimization results of example shows the method proposed is of good effectiveness and engineering applicability.

scholarly journals Topology optimization of partial constrained layer damping treatment on plate for maximizing modal loss factors

2021 ◽  
Vol 30 ◽  
pp. 263498332110348
Author(s):  
Rong Chen ◽  
Haitao Luo ◽  
Hongguang Wang ◽  
Weijia Zhou
Keyword(s):  
Topology Optimization ◽  
Objective Function ◽  
Superposition Method ◽  
Optimization Approach ◽  
Constrained Layer Damping ◽  
Modal Strain Energy ◽  
Thin Walled Structures ◽  
Damping Material ◽  
Constrained Damping ◽  
Loss Factors

Constrained layer damping treatment is widely used to suppress the vibration and noise of thin-walled structures. However, full coverage of constrained damping layer will increase unnecessary additional mass, resulting in material waste and cannot effectively improve the damping performance of the composite structure. In this article, a topology optimization approach is proposed to realize the optimal distribution of constrained damping layer. The design objective is to maximize modal loss factors solved by the modal strain energy method under the constraint of volume. Taking the relative density of the finite element of the constrained damping layer as design variable, the solid isotropic material with penalization method is used to realize the optimal topological distribution of the damping material on the surface of the metal substrate. Then the moving asymptote method is adopted as an optimizer to search the optimal layout of the constrained damping layer. Based on a modified modal superposition method, the sensitivities of the objective function with respect to the design variables are obtained. Numerical examples and experiments are presented for illustrating the validity and efficiency of this approach. The results show that the objective function converges to the optimal value smoothly, and the optimized modal loss factors have been significantly improved. The layouts of the constrained damping layer after optimization are clear and reasonable, and its distributions are affected by both the damping layer and the constraining layer. Each part of the constrained damping layer after optimizing can greatly improve the damping performance of the structure.

Research on Damping Properties of TiN Coating Prepared with Arc Ion Plating

2012 ◽  
Vol 184-185 ◽  
pp. 1167-1170
Author(s):  
Guang Yu Du ◽  
Zhen Tan ◽  
Kun Liu ◽  
Hao Chai ◽  
De Chun Ba
Keyword(s):  
Chemical Composition ◽  
Surface Morphology ◽  
Loss Factor ◽  
Steel Substrate ◽  
Damping Ratio ◽  
Energy Dispersive Spectrometer ◽  
Tin Coating ◽  
Arc Ion Plating ◽  
Ion Plating ◽  
Half Power

In this paper TiN coating was prepared on stainless steel substrate using arc ion plating technique. The coating samples’ phases, surface morphology, micro-determination chemical composition, loss factor and damping ratio were tested. The phases of TiN coating were determined by X-ray diffraction (XRD) technique. The surface morphology and chemical composition of the TiN coating were analyzed by scanning electron microscope (SEM) and Energy Dispersive Spectrometer (EDS), respectively. The damping performance of the samples was measured by hammering activation according half power bandwidth method. The loss factor or damping ratio of samples were obtained according frequency response curve. The results showed that damping performance of samples was considerably improved by TiN coatings.

Sign in / Sign up

Export Citation Format

Share Document