基于能度可靠性的结构优化设计方法

基于可靠性的结构优化设计是不确定性结构设计的最合理途径。本文提出了基于能度可靠性的结构优化设计方法，将不确定结构的优化设计描述为：在重量或造价约束下，极小化结构的失效可能度；或对确定的容许失效可能度，极小化结构重量或造价。所提方法和传统的基于随机可靠性的结构优化设计是平行和相似的。由于结构的能度可靠性模型对已知数据的依赖性较低，计算过程较为简便。从而可使结构设计阶段获取数据的难度大大降低，并有效降低计算工作量，且可使模糊信息的处理更为合理。实例计算说明了文中方法是有效和可行的。

Optimization of uncertain structures based on possibilistic reliability model

The paper deals with the problem of optimization of uncertain structures. Reliability-based optimization of uncertain structures is usually solved using stochastic model, which needs a wealth of data on stochastic parameters and is often a time consuming task. A different strategy which makes use of possibilistic reliability theory we proposed in a previous paper was used here, a new procedure of reliability-based optimization for uncertain structural design was presented, which is parallel to the traditional stochastic-reliability-based optimization procedure. In the context, possibility theory was used to model uncertainties. Structural optimization was described as minimizing the failure possibility of structures for a given weight or cost, or minimizing the weight or cost for a specified allowable failure possibility. Because possibilistic reliability procedure does not require large amount of data, and be easy to compute, the present procedure can make use of limited available information, and reduce the computational cost. A numerical example shows that the present procedure is effective and feasible for optimization of uncertain structures.