曲げ歪エネルギー率を用いた自由曲面シェルの形状評価に関する研究その2 : 形状最適化されたシェルの曲げ歪エネルギ一率

摘要

本研究は、近年建設例が増えている自由曲面シェルの形状の構造性能を評価する指標のひとつとして曲げ歪エネルギー率を用いる事を提案し、本報では、形状最適化を適用して曲げ歪エネルギーの極力小さなシェル形状を求めることで曲げ歪エネルギー率がどのような範囲の値を取るか調査した。本研究で得られた成果を以下に示す。%曲げ歪ェネルギ一; 自由曲面シェル; 形状評価; 形状最適化; 有限要素解析 ;Recently, owing to the development of structural materials and structural analysis technology, various large span structures with complex forms have been built. There might be a structure with a structurally irrational shape among them. For that reason, we proposed an index that can evaluate the structural performance of shell shape in our previous paper. The index is the rate of the bending strain energy in the strain energy caused by external forces, and called the bending strain energy ratio. In this paper, the shell shapes which have as small bending strain energy as possible are found for various boundary shapes and conditions by applying the shape optimization method and the range of values of bending strain energy ratio are investigated. As a result, the bending strain energy ratio could be reduced to 0.2 or less in all models.