scholarly journals Topology Optimization considering Nonsmooth Structural Boundaries in the Intersection Areas of the Components

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Ruichao Lian ◽  
Shikai Jing ◽  
Zefang Shi ◽  
Zhijun He ◽  
Guohua Song
Keyword(s):  
Topology Optimization ◽  
Geometric Modeling ◽  
Compliant Mechanisms ◽  
Optimization Approach ◽  
Structural Topology ◽  
Topology Description Function ◽  
Structural Responses ◽  
Structure Boundary ◽  
Compliance Problem ◽  
The Impact

In the structural topology optimization approaches, the Moving Morphable Component (MMC) is a new method to obtain the optimized structural topologies by optimizing shapes, sizes, and locations of components. However, the optimized structure boundary usually generates local nonsmooth areas due to incomplete connection between components. In the present paper, a topology optimization approach considering nonsmooth structural boundaries in the intersection areas of the components based on the MMC is proposed. The variability of components’ shape can be obtained by constructing the topology description function (TDF) with multiple thickness and length variables. The shape of components can be modified according to the structural responses during the optimization process, and the relatively smooth structural boundaries are generated in the intersection areas of the components. To reduce the impact of the initial layout on the rate of convergence, this method is implemented in a hierarchical variable calling strategy. Compared with the original MMC method, the advantage of the proposed approach is that the smoothness of the structural boundaries can be effectively improved and the geometric modeling ability can be enhanced in a concise way. The effectiveness of the proposed method is demonstrated for topology optimization of the minimum compliance problem and compliant mechanisms.

Design of Grip-and-Move Manipulators Using Symmetric Path Generating Compliant Mechanisms

2008 ◽  
Vol 130 (11) ◽  
Author(s):  
N. F. Wang ◽  
K. Tai
Keyword(s):  
Topology Optimization ◽  
Compliant Mechanisms ◽  
Optimization Procedure ◽  
Problem Formulation ◽  
Optimization Approach ◽  
Structural Topology ◽  
Graph Theoretic ◽  
Mutation Operators ◽  
Future Work ◽  
Crossover And Mutation

This paper presents the problem formulation and design of compliant grip-and-move manipulators. Each manipulator is composed of two identical path generating compliant mechanisms such that it can grip an object and convey it from one point to another. The integration of both gripping and moving behaviors within a simple mechanism is accomplished by the use of compliant mechanisms, which generate paths that are symmetric. The automated synthesis of these symmetric path generating mechanisms is by a structural topology optimization approach. The problem of topology optimization of continuum structures is solved using a multiobjective genetic algorithm coupled with a morphological representation of geometry that efficiently defines the variable structural geometry upon a finite element grid. A graph-theoretic chromosome encoding together with compatible crossover and mutation operators are then applied to form an effective evolutionary optimization procedure. Two designs have been created and are presented in this paper, and some concluding remarks and future work are put forward.

scholarly journals Topology Optimization of Deformable Bodies with Linear Dynamic Impact and Frictionless Contact Condition

2021 ◽  
Vol 11 (22) ◽  
pp. 10518
Author(s):  
Gil-Eon Jeong
Keyword(s):  
Topology Optimization ◽  
Optimization Approach ◽  
Dynamic Impact ◽  
Frictionless Contact ◽  
Linear Dynamic ◽  
Highly Nonlinear ◽  
Simple Part ◽  
Deformable Bodies ◽  
Increasing Demand ◽  
The Impact

There has been an increasing demand for the design of an optimum topological layout in several engineering fields for a simple part, along with a system that considers the relative behaviors between adjacent parts. This paper presents a method of designing an optimum topological layout to achieve a linear dynamic impact and frictionless contact conditions in which relative behaviors can be observed between adjacent deformable parts. The solid isotropic method with penalization (SIMP) method is used with an appropriate filtering scheme to obtain an optimum topological layout. The condensed mortar method is used to handle the non-matching interface, which inevitably occurs in the impact and contact regions, since it can easily apply the existing well-known topology optimization approach even in the presence of a non-matching interface. The validity of the proposed method is verified through a numerical example. In the future, the proposed optimization approach will be applied to more general and highly nonlinear non-matching interface problems, such as friction contact and multi-physics problems.

Design of Compliant Structural Mechanisms Using B-Spline Elements

2011 ◽  
Author(s):  
Ashok V. Kumar ◽  
Anand Parthasarathy
Keyword(s):  
Inverse Problem ◽  
Topology Optimization ◽  
Compliant Mechanisms ◽  
Spline Approximation ◽  
Structural Response ◽  
Field Application ◽  
Optimization Approach ◽  
Objective Functions ◽  
B Spline ◽  
Spline Basis

Structural design is an inverse problem where the geometry that fits a specific design objective is found iteratively through repeated analysis or forward problem solving. In the case of compliant structures, the goal is to design the structure for a particular desired structural response that mimics traditional mechanisms and linkages. It is possible to state the inverse problem in many different ways depending on the choice of objective functions used and the method used to represent the shape. In this paper, some of the objective functions that have been used in the past, for the topology optimization approach to designing compliant mechanisms are compared and discussed. Topology optimization using traditional finite elements often do not yield well-defined smooth boundaries. The computed optimal material distributions have shape irregularities unless special techniques are used to suppress them. In this paper, shape is represented as the contours or level sets of a characteristic function that is defined using B-spline approximation to ensure that the contours, which represent the boundaries, are smooth. The analysis is also performed using B-spline elements which use B-spline basis functions to represent the displacement field. Application of this approach to design a few simple mechanisms is presented.

scholarly journals A local solution approach for level-set based structural topology optimization in isogeometric analysis

2020 ◽  
Vol 7 (4) ◽  
pp. 514-526
Author(s):  
Zijun Wu ◽  
Shuting Wang ◽  
Renbin Xiao ◽  
Lianqing Yu
Keyword(s):  
Topology Optimization ◽  
Level Set ◽  
Isogeometric Analysis ◽  
Iteration Process ◽  
Solid Material ◽  
Optimization Approach ◽  
Structural Topology ◽  
Zero Level ◽  
Solution Approach ◽  
Level Set Function

Abstract This paper develops a new topology optimization approach for minimal compliance problems based on the parameterized level set method in isogeometric analysis. Here, we choose the basis functions as level set functions. The design variables are obtained with Greville abscissae based on the corresponding collocation points. The zero-level set boundaries are derived from the level set function values of the interpolation points in all knot spans. In the optimization iteration process, the whole design domain is discretized into two types of subdomains around the zero-level set boundaries, undesign area with void materials and redesign domain with solid materials. To decrease the size of equations and the computational consumptions, only the solid material area is recalculated and the void material area is discarded according to the high accuracy of isogeometric analysis. Numerical examples demonstrate the validity of the proposed optimization method.

A New Approach for Simultaneous Shape and Topology Optimization Based on Implicit Topology Description Functions

2004 ◽  
Author(s):  
Xu Guo ◽  
Kang Zhao ◽  
Michael Yu Wang
Keyword(s):  
Topology Optimization ◽  
Numerical Experiments ◽  
Shape Derivative ◽  
Structural Topology ◽  
Numerical Instability ◽  
New Approach ◽  
Shape And Topology Optimization ◽  
Topology Description Function ◽  
And Topology ◽  
Non Local

In the present paper, a new approach for structural topology optimization based on implicit topology description function (TDF) is proposed. TDF is used to describe the shape/topology of a structure, which is approximated in terms of the nodal values. Then a relationship is established between the element stiffness and the values of the topology description function on its four nodes. In this way and with some non-local treatments of the design sensitivities, not only the shape derivative but also the topological derivative of the optimal design can be incorporated in the numerical algorithm in a unified way. Numerical experiments demonstrate that by employing this approach, the computational efforts associated with TDF (and level set) based algorithms can be saved. Clear optimal topologies and smooth structural boundaries free from any sign of numerical instability can be obtained simultaneously and efficiently.

Research on Relationship between Weight Filter Function and Stiffness Filter Function

2011 ◽  
Vol 411 ◽  
pp. 580-583
Author(s):  
Zhen Shang ◽  
Yun Kang Sui
Keyword(s):  
Numerical Simulation ◽  
Topology Optimization ◽  
Least Squares Method ◽  
Simulation Method ◽  
Homogenization Method ◽  
Structural Topology Optimization ◽  
Structural Topology ◽  
Filter Function ◽  
The Impact ◽  
The Relationship

Combined with the homogenization method and the least squares method, the filter function with the form of power function is studied in the Independent Continuum Map (ICM) method. Then, the numerical simulation method is used to study the relationship between a weight filter function and a stiffness filter function. Finally, the impact of the filtration function on the efficiency of topology optimization is showed by examples. It is important to further research structural topology optimization.

Innovative Structural Topology Optimization Approach for Rotordynamics Components Using Innovative Materials and New Manufacturing Techniques

2017 ◽  
Author(s):  
Enrico Boccini ◽  
Enrico Meli ◽  
Andrea Rindi ◽  
Simone Corbò ◽  
Giuseppe Iurisci
Keyword(s):  
Topology Optimization ◽  
Three Dimensional ◽  
Optimization Approach ◽  
Complex Structures ◽  
Concept Design ◽  
Structural Topology ◽  
Innovative Strategy ◽  
Innovative Materials ◽  
Manufacturing Techniques ◽  
Near Future

Topology optimization is an innovative strategy applied in the turbomachinery field with the aim of substantially improving the performances of turbomachinery components in terms of weights, stress levels and rotation speed, with a very remarkable economic impact. Being very flexible, topology optimization allows to manage the structures topology, significantly improving material distribution within a given design space for a given set of loads and boundary conditions. In this paper, the authors, in cooperation with General Electric Nuovo Pignone, develop a new concept design of a turbine disk and the optimized component is compared to the benchmark, in order to verify the achieved improvements. Special attention is paid to the use of innovative materials with lattice structures, characterized by complex three-dimensional geometries. Thanks to advanced technologies, as additive manufacturing, it is now possible to effectively exploit topology optimization to develop new components featured by complex structures. The developed prototypes will be manufactured and tested in the near future together with the industrial partners.

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