基于断裂力学理论的结构形状设计优化

采用生物算法对飞机结构中典型开口问题进行基于断裂力学理论的优化设计研究,将以往按照应力优化的思路发展为按照开口边缘应力强度因子优化,采用三次样条函数曲线模拟开口结构形状,以插值节点处的应力强度因子为优化目标,通过调整节点的位置实现优化目的.文中通过两个不同设计域下的算例的优化结果,表明按照文中方法进行结构形状优化,不仅能使整个开口边缘有均匀的应力强度因子,而且能使关键部位的应力强度因子大大降低.

STRUCTURAL SHAPE OPTIMIZATION BASED ON FRACTURE MECHANICS

The biological algorithm was applied to optimize shape design in the typical cut-out on airplane structure.The optimization concept based on stress has been extended to the one based on the virtual crack stress intensity factor,and used cubic spline curve to express the cut-out,studied the stress intensity factor at each node,adjusted the node to make the stress intensity factor along the circumference of the cut-out uniform and also the stress intensity factor at critical node decrease.By two examples of d...