高强度环槽铆钉ML40Cr材料单轴拉伸及低周疲劳性能研究  

Uniaxial tensile and low-cycle fatigue performance of high-strength lockbolt ML40Cr materials

作　　者：徐菲 陆一安 周绪红[1,2] 王宇航 XU Fei;LU Yian;ZHOU Xuhong;WANG Yuhang(College of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area of China Ministry of Education,Chongqing Unversity,Chongqing 400045,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《建筑结构学报》2024年第10期217-228,共12页Journal of Building Structures

基　　金：国家自然科学基金项目(52108116,52221002,52378130);中央高校基本科研业务费专项(2022CDJQY-009)。

摘　　要：为研究环槽铆钉ML40Cr材料的轴拉和低周疲劳力学性能,开展了单调拉伸和等幅低周疲劳试验,研究该材料在单调和循环荷载作用下的塑性性能及其力学性能退化规律,通过扫描电子显微镜观察断口微观形貌,揭示了该材料在单调及不同幅值的循环荷载作用下的失效机理。结果表明:环槽铆钉材料轴拉应力-应变曲线无明显屈服平台,具有一定的塑性变形能力,材料具有较好的低周疲劳性能,疲劳软化呈现初始快速软化、平稳软化和后期剧烈软化的三阶段特征。基于试验结果,提出了适用于该材料的修正的Ramberg-Osgood模型,并验证了Chaboche混合强化本构模型对描述循环荷载作用下铆钉材料塑性性能的适用性,修正的Ramberg-Osgood模型能较为准确地描述环槽铆钉材料的轴拉应力-应变关系。To investigate the mechanical properties of lockbolt ML40Cr material under tensile and low-cycle fatigue,the experiment on lockbolt materials under axial tension and constant amplitude fatigue loading was conducted to obtain the plastic behaviour and the degradation of material properties.Furthermore,the fractography analyses were performed using electron scanning microscope(SEM)on tensile and fatigue specimens,and the underlying failure mechanisms were studied.The experimental results show that the lockbolt material does not exhibit distinct yield plateau in the axial stress-strain curve,and it has both deformation resistance and certain plasticity.The material has good low-cycle fatigue properties,and fatigue softening presents three-stage characteristics including initial rapid softening,smooth softening and later severe softening.Based on the test results,a modified Ramberg-Osgood model was proposed,which can predict the tensile stress-strain relationship with satisfactory accuracy.

关 键 词：环槽铆钉 单调加载 循环加载 力学性能 Ramberg-Osgood模型 滞回性能 

分 类 号：TU391[建筑科学—结构工程] TU317.1