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

  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.