scholarly journals A Cross-sectional Shape Initial Design Method for Automotive Frame Structure Using Genetic Algorithms

2004 ◽  
Vol 70 (689) ◽  
pp. 235-242 ◽  
Author(s):  
Masataka YOSHIMURA ◽  
Shinji NISHIWAKI ◽  
KAZUHIRO IZUI
Keyword(s):  
Genetic Algorithms ◽  
Design Method ◽  
Frame Structure ◽  
Cross Sectional ◽  
Initial Design ◽  
Sectional Shape

A Concurrent Design Method for Multiple Cross-Sectional Automotive Body Frames Involving Discrete and Continuous Design Variables

2003 ◽  
Author(s):  
Masataka Yoshimura ◽  
Shinji Nishiwaki ◽  
Kazuhiro Izui
Keyword(s):  
Design Process ◽  
Design Method ◽  
Analytical Models ◽  
Cross Sectional ◽  
Automotive Body ◽  
Initial Design ◽  
Design Variables ◽  
Mechanical Products ◽  
Cross Sectional Design ◽  
Sectional Shape

As CAE (Computer Aided Engineering) applications become increasingly precise, the knowledge and technical skill required to operate such applications has become more highly specialized. However, such tools have not been utilized in the initial design process of mechanical products, where designers cannot construct detailed analytical models. This paper proposes a cross-sectional shape design optimization system that supports the initial design process for bar structures. The cross-sectional design problem is formulated as an eight-objective optimization problem that can be solved using genetic algorithms. A method for generating cross-sectional shapes satisfying designer-required characteristics is also proposed. These methods, which reduce the number of trial and error processes and product design failures, are expected to enable shortened product development lead-times.

Biomimetic Studies of the Beetle Forewing in China

2013 ◽  
Vol 461 ◽  
pp. 128-143 ◽  
Author(s):  
Cheng Lin He ◽  
Jin Xiang Chen
Keyword(s):  
Cross Sections ◽  
Biological Significance ◽  
Frame Structure ◽  
Tensile Fracture ◽  
Variable Cross ◽  
Cross Sectional ◽  
Chinese Scholars ◽  
Sectional Shape ◽  
Future Work ◽  
Fracture Morphologies

This report reviews biomimetic studies performed in China on the beetle forewing, noting that Chinese scholars studying bionics have substantially advanced various branches of biomimetic research in beetles. The report also proposes the development of branches of bionic research and establishes the foundation for corresponding experiments and theories. Then, using theA. dichotomaforewing as a an example, the cross-sectional shape, orientation of the laminated fiber layers, structure of the trabeculae, and respective mechanical properties of the forewing, as well as their biological significance, are reviewed. 1) The forewing has a lightweight border frame structure and an optimal design of variable cross-sections suitable for different positions, which achieves the specific second moment of inertia required for flight. 2) Due to the non-equiangular, laminated structure of the forewing, there are two types of tensile fracture morphologies: fiber breakage and residual bridging. This study demonstrates the anisotropy and the effectiveness of the forewings tensile strength by analyzing the orientation direction of the fibers. 3) The trabecular structure can be used to efficiently improve the peel resistance of the laminated composites. Based on the above points, possible directions for future work are also indicated in this paper.

Design of C-Frames Using Real-Coded Genetic Optimization Algorithms and NURBS

1999 ◽  
Author(s):  
Ashraf O. Nassef ◽  
Hesham A. Hegazi ◽  
Sayed M. Metwalli
Keyword(s):  
Genetic Algorithms ◽  
Cross Section ◽  
Cross Sections ◽  
Design Parameters ◽  
Binary Representation ◽  
Cross Sectional ◽  
Search Spaces ◽  
The Cross ◽  
Sectional Shape ◽  
Real Coded Genetic Algorithms

Abstract C-frames constitute a large portion of machine tools that are currently used in industry. Examples of these frames include drilling machines, presses, punching and stamping machines, clamps, hooks, etc. The design parameters of these frames include the dimensions of their cross-sections, which should be chosen to withstand the applied loads and minimize the element’s overall weight. Traditionally, the cross-section of C-frame belonged to a set of primitive shapes, which included I, T, trapezoidal and rectangular sections. This paper introduces a new methodology for designing the frame’s cross-section. The cross-sectional shape is represented using non-uniform rational B-Spline (NURBS) in order to give it a form of shape flexibility. A special form of genetic algorithms known as real-coded genetic algorithms is used to conduct the search for the design objectives. Real-coded genetic algorithms are known to outperform the simple binary representation genetic algorithms when dealing with continuous search spaces. The results showed that the optimal shape was a semi I/T-section with the material bulk related to the applied load.

A Cross-Sectional Shape Multiplier Method for Two-Level Optimum Design of Frames

1990 ◽  
Author(s):  
Wenzhong Zhao ◽  
Shapour Azarm
Keyword(s):  
Optimum Design ◽  
Solution Procedure ◽  
Frame Structure ◽  
Multiplier Method ◽  
Configuration Design ◽  
Cross Sectional ◽  
Bottom Level ◽  
Frame Element ◽  
Sectional Shape ◽  
Monotonicity Analysis

Abstract In this paper, a new method for optimum design of frame structures is presented. The method is based on a hierarchical decomposition of the structure into two-levels, namely, the bottom- and the top-level. The bottom-level consists of several subproblems each dealing with the cross-sectional sizing of a given frame-element. The top-level consists of one subproblem which is formulated for configuration design of the frame structure. Since there may be a large number of frame elements, a new shape multiplier method has been developed to simplify the formulation of the bottom-level subproblems. Furthermore, a two-level solution procedure has been developed which first solves the bottom-level subproblems based on their monotonicity analysis. It then solves the top-level subproblem as it coordinates, based on a linear approximation, the solutions to the bottom-level subproblems. Three examples with increasing degree of difficulty are presented to demonstrate the effectiveness of the method.

A Cross-Sectional Shape Multiplier Method for Two-Level Optimum Design of Frames

1993 ◽  
Vol 115 (1) ◽  
pp. 132-142 ◽  
Author(s):  
Wenzhong Zhao ◽  
Shapour Azarm
Keyword(s):  
Optimum Design ◽  
Solution Procedure ◽  
Frame Structure ◽  
Multiplier Method ◽  
Configuration Design ◽  
Cross Sectional ◽  
Bottom Level ◽  
Frame Element ◽  
Sectional Shape ◽  
Monotonicity Analysis

In this paper, a new method for optimum design of frame structures is presented. The method is based on a hierarchical decomposition of the structure into two-levels, namely, the bottom- and the top-level. The bottom-level consists of several subproblems each dealing with the cross-sectional sizing of a given frame-element. The top-level consists of one subproblem which is formulated for configuration design of the frame structure. Since there may be a large number of frame elements, a new shape multiplier method has been developed to simplify the formulation of the bottom-level subproblems. Furthermore, a two-level solution procedure has been developed which first solves the bottom-level subproblems based on their monotonicity analysis. It then solves the top-level subproblem as it coordinates, based on a linear approximation, the solutions to the bottom-level subproblems. Three examples with increasing degree of difficulty are presented to demonstrate the effectiveness of the method.

On the cross-sectional shape of the cellulose crystallites in the tunicate Halocynthia papillosa

1990 ◽  
Vol 48 (3) ◽  
pp. 566-567
Author(s):  
J.-F. Revol ◽  
Y. Van Daele ◽  
F. Gaill
Keyword(s):  
Contrast Imaging ◽  
Animal Kingdom ◽  
Bright Field ◽  
Field Mode ◽  
Cross Sectional ◽  
Ultrathin Sections ◽  
The Cross ◽  
Sectional Shape ◽  
Valonia Ventricosa ◽  
C Nmr

The only form of cellulose which could unequivocally be ascribed to the animal kingdom is the tunicin that occurs in the tests of the tunicates. Recently, high-resolution solid-state l3C NMR revealed that tunicin belongs to the Iβ form of cellulose as opposed to the Iα form found in Valonia and bacterial celluloses. The high perfection of the tunicin crystallites led us to study its crosssectional shape and to compare it with the shape of those in Valonia ventricosa (V.v.), the goal being to relate the cross-section of cellulose crystallites with the two allomorphs Iα and Iβ.In the present work the source of tunicin was the test of the ascidian Halocvnthia papillosa (H.p.). Diffraction contrast imaging in the bright field mode was applied on ultrathin sections of the V.v. cell wall and H.p. test with cellulose crystallites perpendicular to the plane of the sections. The electron microscope, a Philips 400T, was operated at 120 kV in a low intensity beam condition.

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