偏平シェル理論に基づく低次三角形要素を用いた薄肉弾性体の大変形解析法

抄録

In the large displacement analysis of thin shells, a flat triangular finite element has been used for a long time. Such a triangular element is very efficient to analyze a shell with an arbitrary shape numerically. Contraversely, it is impossible to evaluate the effect of the curvature in a shell exactly by the usual flat element. On the other hand, the general shell element which is based on the shell theory, is exact for the reason that it is estimated the curvature, but has been involving important numerical problems, so-called the membrane locking behavior and so on. In this paper, we describe the new large displacement analytical method of shell structures using the triangular finite element proposed by Carpenter et. al. This simple three-node low-order triangular element is baed on Marugerre's shallow shell theory, and is considered having away from the membrane locking behavior. The characteristics of this new numerical analytical method is the formulation technique in applying to the incremental theory. Namely, the local deformed shape of the analysis model is recognized as effect of curvature of the each element like the initial geometrical imperfection, but the global deformed shape of the analytical model is done by updated Lagrangian formulation. At last, we show some numerical examples to examine the validity and efficiency of the present numerical analytical method.