曲面構造の大変形時における抗負荷機構について : (その1)偏平殼の弾塑性大たわみ解析

抄録

Analyzing collapse of a bow structure of ship generated by a wave impact, the approximate method is usually used to replace a shell structure with an arch or a folded plate structure. However, the behaviour of shell structure subjected to large deflection is considerably different from that of simulated arch or plate with respect to interactive effect of double curvatures. The elasto-plastic analysis of shell has complex problem with nonlinearity about geometric and material in which the solutions on stress and deflection are required to be same level of accuracy. One of universal and powerful method for this subject is a finite element method using hybrid or mixed models that generally has inconvenience to be necessarily extensive calculation due to a large number of freedom. This paper presents an improved finite strip method for elasto-plastic analysis of shallow shell to lighten the volume of calculation. In this method, the displacement functions of strip elements are employed the approximate functions based on a governing equation of shallow shell in order to obtain the solutions with a high accuuracy in spite of using a few freedom. Furthermore, the elasto-plastic analysis on three kinds of shells is carried out by use of the proposed method. By the results of examinable analysis, the relations between initial curvatures of shell or yielding stress of material and behaviour of deflection are clarified and the mechanism of resisting external force in shell is considered.