Fail-Safe Optimal Design of Complex Structures With Substructures

1982 ◽  
Vol 104 (4) ◽  
pp. 861-868 ◽  
Author(s):  
D. T. Nguyen ◽  
J. S. Arora
Keyword(s):  
Optimal Design ◽  
Design Sensitivity ◽  
Structural Systems ◽  
Complex Structures ◽  
Design Problems ◽  
Design Algorithm ◽  
Analysis And Design ◽  
Computational Advantage ◽  
Complex Structural ◽  
Fail Safe

In this paper, the problem of fail-safe design of complex structural systems is considered. A substructural formulation for this class of design problems is presented. Constraints are imposed on stresses, deflections, natural frequency, and member sizes. It is shown that a structure can be designed to withstand the projected future damage. It is also shown that the substructural formulation offers computational advantage for both structural analysis and design sensitivity analysis parts of an optimal design algorithm. Fail-safe designs of open truss and closed helicopter tailbooms are obtained using a program developed based on the substructural formulation.

Analysis and Optimal Design of Spatial Mechanical Systems

1987 ◽  
Author(s):  
H. Ashrafeiuon ◽  
N. K. Mani
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Design ◽  
Dynamic Analysis ◽  
Equations Of Motion ◽  
Mechanical Systems ◽  
Design Sensitivity ◽  
General Purpose ◽  
Design Sensitivity Analysis ◽  
Analysis And Design ◽  
Spatial Systems

Abstract This paper presents a new approach to optimal design of large multibody spatial mechanical systems. This approach uses symbolic computing to generate the necessary equations for dynamic analysis and design sensitivity analysis. Identification of system topology is carried out using graph theory. The equations of motion are formulated in terms of relative joint coordinates through the use of velocity transformation matrix. Design sensitivity analysis is carried out using the Direct Differentiation method applied to the relative joint coordinate formulation for spatial systems. Symbolic manipulation programs are used to develop subroutines which provide information for dynamic and design sensitivity analysis. These subroutines are linked to a general purpose computer program which performs dynamic analysis, design sensitivity analysis, and optimization. An example is presented to demonstrate the efficiency of the approach.

Model Reduction in Structural Analysis Using a Multiresolution Analysis

2002 ◽  
Author(s):  
Sudarsanam Chellappa ◽  
Alejandro R. Diaz
Keyword(s):  
Multiresolution Analysis ◽  
Building Blocks ◽  
Structural Systems ◽  
Fine Scale ◽  
Design Problems ◽  
Elastic Systems ◽  
Principal Application ◽  
Complex Structural ◽  
Scale Properties ◽  
And Behavior

A method is presented to reduce the size of models used in analysis of elastic systems. The reduction is accomplished using a multiresolution analysis applied to elasticity operators to average fine scale properties and behavior while limiting loss of information. In discretized form, the method results in smaller matrices that can be used as building blocks to construct larger systems. The principal application envisioned is in design problems involving complex structural systems, such as crash-worthiness design, where very intensive computations demand computational efficiency.

Analysis and design of a modular underactuated mechanism for robotic fingers

2011 ◽  
Vol 226 (1) ◽  
pp. 242-256 ◽  
Author(s):  
S Yao ◽  
M Ceccarelli ◽  
Q Zhan ◽  
G Carbone ◽  
Z Lu
Keyword(s):  
Optimization Problem ◽  
Modular Design ◽  
Optimality Criteria ◽  
Design Problems ◽  
Design Algorithm ◽  
Underactuated Mechanism ◽  
Analysis And Design ◽  
Design Concepts ◽  
Practical Feasibility ◽  
Robotic Fingers

This paper presents an analysis of the design problems and requirements for underactuated mechanisms for robotic fingers. The case of performing a grasping task is considered and a solution is proposed that consists of a series of linked underactuated mechanisms. Optimality criteria are analysed with the aim of formulating a general design algorithm based on a suitable optimization problem. An example of a four-phalanx modular finger is used to highlight the practical feasibility of the proposed modular design concepts and procedures.

A State Space Technique for Optimal Design of Mechanisms

1982 ◽  
Vol 104 (4) ◽  
pp. 792-798 ◽  
Author(s):  
V. N. Sohoni ◽  
E. J. Haug
Keyword(s):  
Optimal Design ◽  
State Space ◽  
Optimization Algorithm ◽  
System Optimization ◽  
Design Sensitivity ◽  
General Purpose ◽  
Design Problems ◽  
Design Variables ◽  
Space Technique ◽  
Element Technique

Problems of optimal design of mechanisms are formulated in a state space setting that allows treatment of general design objectives and constraints. A constrained multi-element technique is employed for velocity, acceleration, and kineto-static analysis of mechanisms. An adjoint variable technique is employed to compute derivatives with respect to design of general cost and constraint functions involving kinematic, force, and design variables. A generalized steepest descent optimization algorithm is employed, using the design sensitivity analysis methods developed, as the basis for a general purpose kinematic system optimization algorithm. Two optimal design problems are solved to demonstrate effectiveness of the method.

Optimal Design of Elastic Linkage Mechanisms With Multi-Frequency Constraints

1994 ◽  
Author(s):  
Zhang Xianmin ◽  
Shen Yunwen ◽  
Liu Hongzhao ◽  
Cao Weiqing
Keyword(s):  
Optimal Design ◽  
Minimum Weight ◽  
Design Sensitivity ◽  
Stability And Convergence ◽  
Bound Constraints ◽  
Frequency Constraints ◽  
Design Algorithm ◽  
Design Variables ◽  
Weight Design ◽  
Flexible Mechanisms

Abstract The paper presents a finite element method for minimum weight design of flexible mechanisms with multiple frequency constraints and upper and lower bound constraints on the design variables. The design algorithm developed in this paper is formulated in terms of the Kuhn-Tucker optimality criterion, in which two damping factors are introduced to guarantee the algorithm possesses good stability and convergence. The first and second order design sensitivity analysies of eigenvalues are presented and the values of the damping factors α and β are recommended. Results of three numerical examples show that the algorithm is stable and the optimal design can be obtained in lsee than fifteen iterations.

Creating Innovative and Efficient Structures and Materials

2013 ◽  
Vol 438-439 ◽  
pp. 439-444
Author(s):  
Yi Min Xie ◽  
Zhi Hao Zuo ◽  
Xiao Dong Huang ◽  
Ji Wu Tang ◽  
Xiao Ying Yang ◽  
...  
Keyword(s):  
Topology Optimization ◽  
Optimal Design ◽  
Structural Optimization ◽  
Structural Systems ◽  
Design Problems ◽  
Practical Applications ◽  
Evolutionary Structural Optimization ◽  
Recent Developments ◽  
Beso Method ◽  
Industrial Projects

Novel and efficient structural and material designs can be realized by topology optimization that is capable of maximizing the performance of structural systems under given constraints. The bi-directional evolutionary structural optimization (BESO) method has been developed into an effective tool for topology optimization of load-bearing structures and materials. The latest advances of BESO are aimed at expanding its practical applications to a wider range of structural systems on both macro and micro scales. This paper presents recent developments of BESO for optimal design problems of a variety of structural systems ranging from buildings of large scales to materials of micro scales. Selected applications are introduced to demonstrate the capability of BESO. Examples presented in this paper are based on research and industrial projects of the Centre for Innovative Structures and Materials (http://www.rmit.edu.au/research/cism) at RMIT University.

Design Sensitivity Analysis and Optimization of Nonlinear Structural Systems With Critical Loads

1990 ◽  
Author(s):  
Jong Sang Park ◽  
Kyung K. Choi
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Design ◽  
Critical Load ◽  
Critical Loads ◽  
Design Sensitivity ◽  
Design Sensitivity Analysis ◽  
Shape Design ◽  
Structural Systems ◽  
Nonlinear Structural ◽  
Design Variables

Abstract A continuum formulation for design sensitivity analysis of critical loads is developed for nonlinear structural systems that are subjected to conservative loading. Both geometric and material nonlinear effects are considered. Sizing design variables such as cross-sectional areas of beam or truss design components and thicknesses of plate or membrane design components, together with their shape design variables, are treated. A continuum approach is used to obtain design sensitivity expressions in integral form. For shape design sensitivity analysis, the material derivative concept and domain method are used to find variations of the critical load due to variations in shape of the physical domain. The total Lagrangian formulation for incremental equilibrium equation and one-point linearized eigenvalue problems are utilized. A numerical method is presented to evaluate continuum design sensitivity expressions using analysis results of established finite element codes. It is found that no adjoint system is necessary for design sensitivity analysis of the critical load. Numerical results show the proposed method for design sensitivity of critical loads is accurate for both sizing and shape design variables. A numerical procedure for optimal design of nonlinear structural systems is presented, using the proposed continuum design sensitivity analysis method. An optimal design problem with a stability constraint is solved.

Design Sensitivity Analysis and Optimization of Nonlinear Structural Systems With Critical Loads

1992 ◽  
Vol 114 (2) ◽  
pp. 305-312 ◽  
Author(s):  
Jong Sang Park ◽  
Kyung K. Choi
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Design ◽  
Critical Load ◽  
Critical Loads ◽  
Design Sensitivity ◽  
Design Sensitivity Analysis ◽  
Shape Design ◽  
Structural Systems ◽  
Nonlinear Structural ◽  
Design Variables

A continuum formulation for design sensitivity analysis of critical loads is developed for nonlinear structural systems that are subjected to conservative loading. Both geometric and material nonlinear effects are considered. Sizing design variables such as cross-sectional areas of beam or truss design components and thicknesses of plate or membrane design components, together with their shape design variables, are treated. A continuum approach is used to obtain design sensitivity expressions in integral form. For shape design sensitivity analysis, the material derivative concept and domain method are used to find variations of the critical load due to variations in shape of the physical domain. The total Lagrangian formulation for incremental equilibrium equation and one-point linearized eigenvalue problems are utilized. A numerical method is presented to evaluate continuum design sensitivity expressions using analysis results of established finite element codes. It is found that no adjoint system is necessary for design sensitivity analysis of the critical load. Numerical results show the proposed method for design sensitivity of critical loads is accurate for both sizing and shape design variables. A numerical procedure for optimal design of nonlinear structural systems is presented, using the proposed continuum design sensitivity analysis method. An optimal design problem with a stability constraint is solved.

Sign in / Sign up

Export Citation Format

Share Document