A Study on an Intelligent Optimum Material Design System for Utilization of the Anisotropy of Composite Materials

点击翻译按钮获取中文摘要

For the complete utilization of the anisotropy of composite materials, the following aspects are necessary to study: 1) the construction of the design method for structures with the anisotropy in structural mechanics, 2) the development of the theoretical method for designing anisotropy in the material, and 3) the development of an expert system which yields practical aid for structural designers. From these points of view, the research has been conducted as follows:(1) Functional Deformation : The methods for designing a material with negative Poisson's ratio and a structure which has a specified bending-torsion coupling deformation were constructed. Good agreement was found between the analytical and the experimental results. An application of the methods a cantilevered pipe which yields torsional angle of zero at the tip under torsional loading.(2) Optimum Material Design Based on Strain Energy : The bending stiffness of plates are maximized by making its strain energy minimum. Optimum orientation angle of a plate was obtained using this approach for any loading conditions.(3) Optimum Material Design Based on Reliability : It was found that optimum fiber orientation angles under deterministic loading conditions are different from those under probabilistic loading conditions. For probabilistic loading conditions, optimum orientations were obtained using the AFOSM ( advanced first-order second-moment method. Additionally an analytical method for determining optimum angles based on rehability has been proposed. The method is very effective in evaluating the relative value of the reliability.(4) Material Design System with Artificial Intelligence : The knowledges for optimum material design were analyzed and classified, and their hierarchical structures were constructed. The representation of the knowledge was performed by using object-oriented language, Smalltalk, and a trial expert system for composites design has been successfully developed.