基于断裂力学的材料低温疲劳寿命估算模型改进研究  

Reserarch of the Improvement of Materials Fatigue Life Estimation Model Based on Fracture Mechanics in Low Temperature Environment

作　　者：潘韦廷 薛齐文 王尕平[1] 杜秀云 PAN Weiting;XUE Qiwen;WANG Gaping;DU Xiuyun(School of Civil Engineering,Dalian Jiaotong University,Dalian 116028,China;Wuhan Ecological Environment Design and Research Institute Co.,Ltd.,Wuhan 430050,China;State Key Laboratory of Structural Analysis for Industrial Equipment,Dalian 116023,China;School of Physical and Electronic Technology,Liaoning Normal University,Dalian 116029,China)

机构地区：[1]大连交通大学土木工程学院,辽宁大连116028 [2]武汉生态环境设计研究院有限公司,湖北武汉430050 [3]大连理工大学工业装备结构分析重点实验室,辽宁大连116023 [4]辽宁师范大学物理与电子技术学院,辽宁大连116029

出　　处：《国防交通工程与技术》2022年第4期13-18,共6页Traffic Engineering and Technology for National Defence

基　　金：国家自然科学基金(10802015);辽宁省自然科学基金(2019KF0204);大连理工大学工业装备结构分析国家重点实验室开放课题(GZ19204);辽宁省高等学校创新人才支持计划(2020)。

摘　　要：针对低温疲劳裂纹扩展速率模型中工程材料疲劳极限难以测定的问题,考虑裂纹扩展应力强度因子门槛值,将屈服强度、抗拉强度及环境温度引入疲劳极限的计算,分别采用热激活模型和引入温度敏感因子对疲劳极限进行修正,并基于断裂力学方法构建低温疲劳寿命改进模型。根据桥梁常用钢材Q345qD母材及对接焊缝在不同低温环境下的试验数据,对改进疲劳寿命模型估算能力进行验证。结果表明:在低温环境下,估算效果较好,所需参数较少且易测得,便于在实际工程中分析及应用。In view of the difficulty in determining the material fatigue limit in the fatigue crack growth rate model under the low temperature environment,considering the influence of factors such as the threshold value of the crack growth stress intensity factor,the yield strength,tensile strength and ambient temperature are introduced into the calculation of the fatigue limit,the thermal activation model and the temperature sensitive factor are respectively used to correct the fatigue limit,and the improvement model of the fatigue life in low-temperature is constructed based on the fracture mechanics method.According to the experimental data of Q345qD base material and butt welds in different low temperature environments,the estimation ability of the improved fatigue life model is verified.The results show that the improved estimation model of the fatigue life has good estimation effect,it requires fewer parameters which are easy to measure,so it is convenient for analysis and application in practical engineering.

关 键 词：工程材料 低温疲劳寿命 改进模型 数值计算 断裂力学 疲劳裂纹 扩展速率 

分 类 号：TG453.9[金属学及工艺—焊接]