Proposal of a modified optimality criteria method for topology optimization analysis in 3‐dimensional dynamic oscillation problems†

2021 ◽  
Author(s):  
Masayuki Kishida ◽  
Takahiko Kurahashi
Keyword(s):  
Topology Optimization ◽  
Optimality Criteria ◽  
Optimization Analysis ◽  
3 Dimensional ◽  
Optimality Criteria Method

scholarly journals Substructure-Based Topology Optimization for Symmetric Hierarchical Lattice Structures

Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 678
Author(s):  
Zijun Wu ◽  
Renbin Xiao
Keyword(s):  
Topology Optimization ◽  
High Efficiency ◽  
Spline Interpolation ◽  
Optimization Method ◽  
Optimality Criteria ◽  
Lattice Structures ◽  
Hierarchical Lattice ◽  
B Spline ◽  
Design Variables ◽  
Optimality Criteria Method

This work presents a topology optimization method for symmetric hierarchical lattice structures with substructuring. In this method, we define two types of symmetric lattice substructures, each of which contains many finite elements. By controlling the materials distribution of these elements, the configuration of substructure can be changed. And then each substructure is condensed into a super-element. A surrogate model based on a series of super-elements can be built using the cubic B-spline interpolation. Here, the relative density of substructure is set as the design variable. The optimality criteria method is used for the updating of design variables on two scales. In the process of topology optimization, the symmetry of microstructure is determined by self-defined microstructure configuration, while the symmetry of macro structure is determined by boundary conditions. In this proposed method, because of the educing number of degree of freedoms on macrostructure, the proposed method has high efficiency in optimization. Numerical examples show that both the size and the number of substructures have essential influences on macro structure, indicating the effectiveness of the presented method.

Topology Optimization of Electrostatically Actuated Micromechanical Structures With Accurate Electrostatic Modeling of the Interpolated Material Model

2006 ◽  
Author(s):  
Aravind Alwan ◽  
G. K. Ananthasuresh
Keyword(s):  
Topology Optimization ◽  
Electrostatic Force ◽  
Material Model ◽  
Optimality Criteria ◽  
Electrostatically Actuated ◽  
Optimality Criteria Method ◽  
Material State ◽  
Material Interpolation ◽  
New Formulation ◽  
Electrostatic Modeling

In this paper, we present a novel formulation for performing topology optimization of electrostatically actuated constrained elastic structures. We propose a new electrostatic-elastic formulation that uses the leaky capacitor model and material interpolation to define the material state at every point of a given design domain continuously between conductor and void states. The new formulation accurately captures the physical behavior when the material in between a conductor and a void is present during the iterative process of topology optimization. The method then uses the optimality criteria method to solve the optimization problem by iteratively pushing the state of the domain towards that of a conductor or a void in the appropriate regions. We present examples to illustrate the ability of the method in creating the stiffest structure under electrostatic force for different boundary conditions.

Review of Methods of Mechanical Digital Design Based on Topology Optimization

2013 ◽  
Vol 288 ◽  
pp. 193-201
Author(s):  
Xiu Ye Wang ◽  
Han Zhao ◽  
Zu Fang Zhang ◽  
Yong Wang
Keyword(s):  
Topology Optimization ◽  
Optimization Algorithms ◽  
Optimality Criteria ◽  
Digital Design ◽  
Structural Topology ◽  
Optimality Criteria Method ◽  
Mathematical Programming Method ◽  
Pde Methods ◽  
Volume Method ◽  
Element Method

The basic mathematical model of topology optimization of continuum structures is introduced at first. Then the authors focus on reviewing the development of PDE methods and optimization algorithms. This paper details the development and applications of Finite Element Method, Boundary Element Method and Finite Volume Method. This paper also illustrates several typical applications and achievements of optimization algorithms, such as Optimality Criteria method, mathematical programming method and intelligent algorithm. Based on our research, this paper finally summarizes the process of the structural topology optimization and describes the directions of the topology optimization in the field of mechanical digital design.

Topology Optimization with a Penalty Factor in Optimality Criteria

2011 ◽  
Vol 317-319 ◽  
pp. 2466-2472 ◽  
Author(s):  
Xiu Peng Wang ◽  
Shou Wen Yao
Keyword(s):  
Topology Optimization ◽  
Design Variable ◽  
Numerical Stability ◽  
Optimality Criteria ◽  
Penalty Factor ◽  
Structural Density ◽  
Optimality Criteria Method ◽  
Numerical Instabilities ◽  
Nodal Density ◽  
Intermediate Density

Topology optimization is one of the most important methods of reducing the weight of structure. Optimality Criteria method (OC) as a heuristic way can be used to deal with this problem efficiently. Popular SIMP method implements micro-structural density as the design variable. During the process of optimization, numerical instabilities are always observed; Moreover, higher penalty factor is not better for decreasing intermediate density elements. In this paper a penalty factor is imposed in OC method, and a relation between the filtering area and elements is also obtained. Meanwhile, the nodal density is used as design variable for more smoothing boundary. The results show that numerical stability can be obtained, checkerboard patterns haven’t been observed, and the clear boundary of structure has been developed.

scholarly journals Generalized Optimality Criteria Method for Topology Optimization

2021 ◽  
Vol 11 (7) ◽  
pp. 3175
Author(s):  
Nam H. Kim ◽  
Ting Dong ◽  
David Weinberg ◽  
Jonas Dalidd
Keyword(s):  
Topology Optimization ◽  
Lagrange Multipliers ◽  
Inequality Constraints ◽  
Optimality Criteria ◽  
Multiple Constraints ◽  
Numerical Examples ◽  
Method Of Moving Asymptotes ◽  
Design Variables ◽  
Optimality Criteria Method ◽  
Moving Asymptotes

In this article, a generalized optimality criteria method is proposed for topology optimization with arbitrary objective function and multiple inequality constraints. This algorithm uses sensitivity information to update both the Lagrange multipliers and design variables. Different from the conventional optimality criteria method, the proposed method does not satisfy constraints at every iteration. Rather, it improves the Lagrange multipliers and design variables such that the optimality criteria are satisfied upon convergence. The main advantages of the proposed method are its capability of handling multiple constraints and computational efficiency. In numerical examples, the proposed method was found to be more than 100 times faster than the optimality criteria method and more than 1000 times faster than the method of moving asymptotes.

Structural Dynamic Topology Optimization and Sensitivity Analysis Based on RKPM

2010 ◽  
Vol 97-101 ◽  
pp. 3646-3650 ◽  
Author(s):  
Jian Ping Zhang ◽  
Shu Guang Gong ◽  
Yan Kun Jiang
Keyword(s):  
Sensitivity Analysis ◽  
Topology Optimization ◽  
Optimality Criteria ◽  
Localized Modes ◽  
Structural Dynamic ◽  
Direct Differentiation Method ◽  
Optimality Criteria Method ◽  
Dynamic Topology ◽  
The Mathematical Model ◽  
Analysis Equation

A numerical method for structural dynamic topology optimization and sensitivity analysis is presented by using RKPM. In this paper, the relative density of node and maximum fundamental eigenfrequency is respectively chosen as design variable and the objective function, and then the mathematical model for dynamic topology optimization based on RKPM is built. During the process of modeling, some effective measures are taken to dispose the multi-eigenvalues and localized modes. Subsequently, the sensitivity analysis equation is proposed by using Direct Differentiation Method. Finally, by integrating the above sensitivity analysis with Optimality Criteria method, the dynamic topology optimization of an example is performed successfully. Numerical example shows that both checkboards and localized eigenmodes do not occur during topology optimization, and it indicates the proposed method is valid.

Topology Optimization of Continuum Structures Based on SIMP

2011 ◽  
Vol 255-260 ◽  
pp. 14-19 ◽  
Author(s):  
Hong Zhang ◽  
Xiao Hui Ren
Keyword(s):  
Mathematical Model ◽  
Topology Optimization ◽  
Isotropic Material ◽  
Optimization Design ◽  
Optimality Criteria ◽  
Continuum Structures ◽  
Good Convergence ◽  
Minimum Compliance ◽  
Design Variables ◽  
Optimality Criteria Method

An Optimality Criteria method for topology optimization of continuum structures based on Solid Isotropic Material with Penalization (SIMP) was proposed. The minimum compliance of structures was selected as the objective function of the problem. A mathematical model for topology optimization design of statically loaded structures and the update scheme for the design variables were set. The examples showed that the algorithm has good convergence and application values.

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