点焊接头疲劳损伤过程中的固有频率变化特性研究  

VARIATION OF NATURAL FREQUENCY FOR SPOT-WELDED JOINTS DURING FATIGUE DAMAGE PROCESS

作　　者：沈通[1] 尚德广[1] 王瑞杰[1] 李力森[1] 丁雷[1] 阎楚良[1] 

机构地区：[1]北京工业大学机械工程与应用电子技术学院,北京100022

出　　处：《机械强度》2007年第2期294-299,共6页Journal of Mechanical Strength

基　　金：北京市自然科学基金(3042003)资助项目~~

摘　　要：利用有限元模拟和动态响应实验对单点点焊接头的疲劳过程中固有频率变化的特性进行研究。结果表明,三维有限元模拟与实验结果相吻合,能较好地模拟点焊接头在两种疲劳裂纹萌生和扩展的过程中频率的变化情况。并利用所模拟的裂纹长度和固有频率的关系,总结出最适宜对疲劳损伤进行研究的模态阶数。The characteristics of natural frequency were investigated based on the simulation by 3D finite element analysis and the dynamic response experiments for spot-welded specimens during the fatigue damage process. The fatigue propagation behavior from the surface elliptical crack at the initiation stage to the through thickness cracks at the final stage was taken into consideration during the finite element dynamic response simulations. For two kinds of fatigue crack propagation behaviors, the changes of natural frequency were simulated by the finite element analysis. The results of the simulations showed that good agreement is achieved with experimental data. The number of mode which can be used for the fatigue damage analysis, is identified by using the relationship between the simulated crack length and the natural frequency.

关 键 词：疲劳 点焊接头 三维有限元 动态响应 固有频率 模态分析 

分 类 号：TG405[金属学及工艺—焊接] TG407