具有特殊肋骨型式的耐压壳体强度与极限承载能力分析

基于ANSYS有限元分析软件对具有装配型和宽扁型2种特殊肋骨型式的耐压壳体进行强度与极限承载能力分析.针对装配型肋骨的耐压壳体,对比其与传统加筋圆柱壳的强度特性,分析其在不同载荷下的应力分布,以及肋骨与壳体之间的装配间隙对极限承载能力的影响;针对宽扁型肋骨的耐压壳体,分别采用体单元和壳、梁单元进行有限元模拟,分析2种建模方式下结构强度及极限承载能力计算结果的差异性.计算结果表明：具有装配型肋骨的耐压壳体,外载荷与结构应力之间存在非线性关系,装配间隙越小,极限承载能力越强;具有宽扁型肋骨的耐压壳体,2种建模方式对其强度结果有一定的影响,而对极限承载能力的结果影响不大.

Strength and Ultimate Carrying Capacity Analysis ofCylindrical Shells with Special Ribs

In this paper,the strength and ultimate carrying capacity of cylindrical shells with assembly-type ribs and with flat ribs are calculated respectively using the finite element method. The differencein strength between these two types of shells is studied. The stress responses at three typical positions onthe shell with assembly-type ribs are calculated for different loads,and the effect of the assembly gap onthe ultimate carrying capacity is also analyzed. Then,for the cylindrical shell with flat ribs,the differenceof strength and ultimate carrying capacity results by using different modeling methods are investigated. Simulation results show that the non-linearity relationship between the pressure and stress can be clearly observed for the cylindrical shell with assembly-type ribs;specifically,the smaller the assembly gap is,thelarger the ultimate carrying capacity becomes. Meanwhile,for cylindrical shells with flat ribs,the effect ofcomputational modeling on strength,either being Solid elements only or the combination of Sshell andBeam elements,is quite obvious,while that on the ultimate carrying capacity is negligible.