摘要
由于材料特性、构件的几何特性、载荷历程和环境条件等随机因素的影响,造成结构的疲劳寿命往往偏离结构的设计寿命。为了减少疲劳寿命的分散性,建立一种结构疲劳寿命稳健性优化模型。该模型将结构优化设计理论和随机有限元法相结合,在考虑设计变量和其他随机变量的变异性对结构疲劳寿命影响情况下,将结构疲劳寿命稳健性优化问题构造成包含结构疲劳寿命均值和标准差的双目标优化问题,并通过权因子来平衡结构疲劳寿命的均值和标准差关系,在约束函数中将结构疲劳寿命控制在最低寿命和最高寿命之间。经疲劳稳健性优化设计后的结构疲劳寿命在其均值处波动较小,而且分布曲线远离疲劳寿命底限。最后通过承受脉冲载荷的平面10杆桁架结构疲劳寿命稳健性优化算例显示了此方法的有效性。
Due to the random factors such as material properties, geometrical characteristic of structural member, load history and environmental condition, the fatigue life of structure often deviates from the design life. To reduce the scatter of fatigue life, a robust optimization model of structural fatigue life is presented. The model combines structural optimization theory and stochastic finite element method. Under the condition of considering the effects of variance of design variables and other random variables on the structural fatigue life, the problem is formulated as a multi-criteria optimization problem, in which both the mean structural fatigue life and the standard deviation of structural fatigue life are to be minimized. The relationship between the mean structural fatigue life and the standard deviation of structural fatigue life can be balanced by a weight factor. The structural fatigue life is limited between the low fatigue life and high fatigue life in the constrain functions. Fatigue life of the structure optimized by the proposed method has a relative small fluctuation at the mean value and keeps far away frorn the ultimate fatigue life. A numerical example is performed for a planar 10-bar truss. The result shows that the proposed method is feasible and applicable.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2010年第2期155-158,共4页
Journal of Mechanical Engineering
基金
教育部博士点基金(20060183063)
吉林省科技厅基金(20060538)资助项目
关键词
稳健性设计
疲劳寿命
结构优化
随机有限元
随机性
Robust design Fatigue life Structural optimization Stochastic finite element method Randomness
