薄肉筒体の最大曲げモーメントの評価

抄録

In this study, the elastoplastic bending collapse of thin-walled tubes subjected to statically pure bending has been studied by using finite element method (FEM).There are many researches about thin-walled tubes subjected to statically pure bending, but there are few researches about elliptic tubes. In Particular, the effects of tube's geometries (high length a, and width length b) and on the maximum bending moment were discussed by comparing with cylindrical tube. It is revealed that the maximum moment of the elastoplastic tubes are controlled by the flattening ratio of tube. Also, it is shown that the flattening ratio of tube can be expressed by axial and circumferential stress as function of the material and geometrical properties and curvatures. Based on FEM results, the stress distribution of elliptical tube is similar to that of cylindrical tube. On the other hand, the flattening ratio of elliptical tube is approximated by using the modified coefficient relating the aspect ratio (b/a). By approximating the flattening ratio of elliptic tube, maximum moment of elliptic tube can be estimated with a good accuracy.