積層パラメータの離散誤差最小化による複合材積層板の座屈特性最適化

摘要

高分子系繊維強化複合材料（FRP)は，高い比強度と 比剛性を有しているため自動車や航空・宇宙機器など の軽量化構造材料として活用されている．そのうち FRP積層板は，カーボン繊維など強化長繊維と母材か ら構成される薄い異方性ラミナを積層して作られる． その配向角度により積層板全体の力学特性が変化する ことから，より効率的に目的を満たす構造を得るため には積層する繊維配向角度を最適に設計することが重 要である．%The fiber reinforced plastics (FRP) have been utilized in various structural applications of automobile and aerospace industries because they have excellent features of high specific strength and stiffness ratios. The FRP composites are fabricated typically by stacking orthotropic layers, each of which is composed of reinforcing fibers and matrix materials. In this work, an optimum design approach is proposed to optimize buckling performance of laminated composite plates by using the lamination parameters. The approach consists of two parts: the first part is to optimize the lamination parameters by a gradient method, and the second part is to obtain the optimum lay-up design for the maximum buckling loads by minimizing the errors between the opimum parameters and the parameters for all possible discrete lay up designs. Th feedback concept is considered to ensure the global solutions. It is shown in numerical examples that the proposed approach is quite effective in determining the lay-up design for the best buckling performance.