静载和疲劳荷载共同作用下结构可靠性优化设计

Structural reliability optimum design under a dead load and fatigue load

通过对静载和疲劳载荷共同作用下结构系统的可靠性分析,得到了结构系统可靠性指标的计算式,并将可靠性指标作为约束函数建立优化模型,对结构的重量进行优化.采用改进的遗传算法进行结构优化设计,通过对编码方式和遗传算子的改进,使收敛性能大大改善,提高了局部搜索能力.算例表明,改进的遗传算法是一种解决静载和疲劳荷载共同作用的高效结构优化方法.

Structural reliability under a dead load and fatigue load was analyzed,and a calculated formula of the structural reliability index was obtained.Then the reliability index was considered as a restricted function to develop an optimum model,and the structural weight was optimized.An improved genetic algorithm was adopted to carry out structural optimum design,and the code mode and genetic operator were improved.The convergence performance was also improved greatly,and the local search ability was increased.Calculated examples indicate that the improved genetic algorithm is a highly effective method to produce the optimum structural reliability design under a dead load and fatigue load.