失效模式约束下层级褶皱结构的多目标优化  

MULTI-OBJECTIVE OPTIMIZATION OF HIERARCHICAL CORRUGATED STRUCTURE UNDER FAILURE MODES CONSTRAINTS

作　　者：李兆凯[1,2] 方耀楚[3] 郝鹏[1] 李刚[1] 

机构地区：[1]大连理工大学工程力学系,工业装备结构分析国家重点实验室,大连116024 [2]北京机械设备研究所,北京100854 [3]南华大学城市建设学院,衡阳421001

出　　处：《工程力学》2017年第5期226-234,共9页Engineering Mechanics

基　　金：973项目(2014CB046506);国家自然科学基金项目(11372061,11402049);中国博士后科学基金项目(2015T80246)

摘　　要：基于欧拉梁和弹性薄板理论,该文分析了二级层级褶皱结构的板模型在剪切或压缩载荷下对应的六种失效模式及对应的名义应力。通过比较名义应力值,控制发生的失效模式类型,并结合多目标优化算法,同时进行最小重量和最小挠度的性能优化。该文建立了两种优化模型:一是控制首次发生的失效模式类型;二是根据损失大小将失效模式分级,并按照等级序列发生。在此基础上,讨论了两种优化模型的Pareto前沿图中典型设计点的性能指标,最后采用有限元分析验证失效模式类型。结果表明:两种优化模型得到的结构设计,分别与控制发生的类型一致,综合性能得到极大提升;第二种模型考虑了应力值的差异,防止结构突然发生整体失效,更加安全。Six failure modes may occur for hierarchical corrugated structures under compressive or shear loads, and the corresponding nominal stress of plate model were analyzed based on the theories of Euler beams and elastic plates in this study. The failure modes were designed by comparing the nominal stress, and then the multi-objective optimization was performed to minimize both weight and deflection. Two optimization formulations were established, with one controlling a special failure mode occurs first and another classifying the failure modes into two grades considering the loss degree, and then the failure mode occurs as a specific sequence. On this basis, the performance index of several typical design points from the Pareto front of two models was discussed. Finally, the failure modes were verified by FEM. The results show significant improvement of the performance for both models, and the failure modes occur as expected. The second model is safer, in which the difference of nominal stress for each failure mode is considered, in order to avoid sudden occurrence of global failure.

关 键 词：层级褶皱结构 失效模式 多目标优化 轻量化 最小挠度 

分 类 号：O342[理学—固体力学]