肋骨许用应力对环肋圆柱壳结构设计的影响

Influence of allowable stress on structural design of ring-stiffened cylindrical shells

[目的]旨在研究不同肋骨的许用应力对圆柱壳结构设计的影响。[方法]采用全因子试验设计和信息熵方法,建立基于综合裕度的环肋圆柱壳多目标优化模型,并利用宽容度排序法对建立的多目标优化模型进行优化求解,以及通过改变肋骨许用应力安全系数,分析肋骨许用应力对圆柱壳各属性均匀度的影响。[结果]结果表明,圆柱壳肋骨应力为主要设计约束,当肋骨许用应力安全系数为0.675时,圆柱壳各属性裕度较均匀,约15%,此时结构重量也相对较小。[结论]因此,适当放宽肋骨许用应力可以解决肋骨应力为结构设计主要约束问题,使最优解的各属性裕度之间更加均匀。

[Objective]This paper aims to study the influences of different allowable stresses of ribs in cylindrical shell design.[Methods]To this end,this paper uses full factorial experimental design and information entropy method to establish a multi-objective optimization model of ring-stiffened cylindrical shells based on the weighted-sum method,then uses the tolerance ranking method to optimize the solution of the model.Through changing the safety factor of allowable stress of ribs,the influences of them on the uniformity of the attributes of the cylindrical shell are analyzed.[Results]The results show that the rib stress is the main constraint in design.When the safety factor of the allowable stress of ribs is 0.675,the margins of each attribute value are more uniform at about 15%,and the structural weight is relatively small at this time.[Conclusions]Therefore,properly extending the allowable stress can solve the problem being the main constraint in structural design,and make the margins of each attribute value of the optimal solution more uniform.