考虑循环软化的箱型承载结构安定性分析  

Shakedown Analysis of Box Bearing Structure by Considering Cyclic Softening Effect

作　　者：邹宗园[1] 韩舒婷 王宏中 李群[1] 郭宝峰[1] 金淼[1] ZOU Zongyuan;HAN Shuting;WANG Hongzhong;LI Qun;GUO Baofeng;JIN Miao(Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of Education,Yanshan University,Qinhuangdao 066004)

机构地区：[1]燕山大学先进锻压成形技术与科学教育部重点实验室,秦皇岛066004

出　　处：《机械工程学报》2021年第2期62-69,共8页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51905467);河北省自然科学基金(E2020203104);材料成形与模具技术国家重点实验室开放课题研究基金(P2019-018)资助项目。

摘　　要：安定性分析是承受循环载荷作用的结构设计与安全评定的重要理论依据,更能反映结构的实际承载能力。材料在循环载荷作用下会呈现一定的循环硬化/软化特性,从而影响结构的安定性。以常用的Q235钢为研究对象,分别对Q235板材进行单向拉伸和对称应变控制的循环加载试验,测量相应的应力-应变曲线及材料力学性能参数,研究其单向拉伸性能及循环硬化/软化特性。运用试验所测得的不同加载条件下的材料参数对箱型承载结构进行安定性数值分析,并与文献中该箱型结构的安定性试验研究结果进行对比。结果表明,Q235在循环载荷作用下表现出循环软化特性。采用单向拉伸条件下的性能参数得到的安定性分析结果与物理试验结果相比,误差为25.3%;采用材料循环加载条件下的性能参数得到的安定性分析结果与物理试验结果相比,误差为6.7%,考虑循环软化特性时安定性分析结果更接近物理试验结果。Shakedown analysis is an important theoretical basis for structural design and safety assessment under cyclic loading, and it can better reflect the actual carrying capacity of the structure. The material might exhibit cyclic hardening/softening features under cyclic loading, which affects the shakedown of the structure. Taking the commonly used Q235 steel as the research object material, the Q235 sheet is subjected to uniaxial tension and uniaxial symmetric strain controlled cyclic loading tests, and the corresponding stress-strain curve and material mechanical parameters are measured to study its uniaxial tensile properties and cyclic hardening/softening features. The shakedown of the box bearing structure is analyzed numerically using the material parameters measured under above different loading conditions, and the numerical results are compared with the experimental result in the literature. The result show that Q235 exhibits cyclic softening features under the cyclic loading. Compared with the result of physical experiments, the error of the shakedown analysis result obtained by using uniaxial tensile performance parameters is about 25.3%;the error of the result obtained by using cyclic performance parameters is about 6.7%, and the shakedown analysis result considering cyclic softening effect is closer to the result of physical experiment.

关 键 词：循环硬化/软化 循环应力-应变曲线 安定极限载荷 箱型承载结构 Q235 

分 类 号：TG315[金属学及工艺—金属压力加工]