【摘要】 采用区间模型描述不确定参数,在考虑传统约束条件基础上,增加了可靠性指标作为约束条件,研究结构的稳健性优化设计.从非概率可靠性指标的几何意义出发,寻找非概率可靠性指标目标值与不确定参数的波动范围的关系,将非概率的稳健优化设计转化为两层优化模型.对于非线性功能函数,内层优化根据非概率可靠性指标的波动范围最小化功能函数,从而避免了内层优化直接计算非概率可靠性指标难的问题.对于线性功能函数,不确定性参数可以表示为非概率可靠性指标目标值的显示表达式,两层稳健优化转化为确定性的单层优化.该方法优化描述明确清晰,计算公式简便,计算效率高.算例验证了本文所提方法的可行性和正确性.更多还原

【Abstract】 The structural robust optimization with uncertain parameters which are described by interval models was investigated.Compared with the traditional optimization design,the robust optimization model involves the non-probabilistic reliability index as an constraint condition.In this contribution,the relationship between the target of non-probabilistic reliability index and the fluctuation range of uncertain parameters was depicted by the geometric meaning of the reliability index.The non-probabilistic robust optimization design model was converted into a two-level optimization model.The minimization for non-linear performance function was carried out according to the fluctuant range of the non-probabilistic reliability index within the inner-lever optimization,so as to avoid the calculation of reliability index directly.For the linear performance function,the uncertain parameters could be described as the target value of non-probabilistic reliability index with explicit expression,and therefore the two-level robust optimization was easily converted into a single-level deterministic optimization.The advantages of the proposed method lie in clear geometric characterization,computing convenience and high calculation efficiency.Several numerical examples are calculated,which show the proposed method is efficient.更多还原