对单点与两点拉剪点焊试样分别进行了疲劳试验,观测了疲劳裂纹的形状和萌生位置,通过动态响应实验测量了疲劳破坏过程中固有频率的变化。对比两种试样的载荷幅寿命关系,认为两点试样的承载能力约为单点试样的两倍。有限分析了两种试样失效时的固有频率比,基于所测量的固有频率,确定了单点与两点试样疲劳失效时的频率比,对比了疲劳过程中的损伤。 Fatigue tests were carried out on single-point and two-point pull-spot-welded specimens respectively. The shape and initiation position of fatigue crack were observed. The dynamic response experiment was used to measure the change of natural frequency during fatigue failure. Comparing the load life relationship between the two specimens, it is considered that the load capacity of the two specimens is about double that of the single specimen. Based on the measured natural frequency, the frequency ratio of single-point and two-point samples during fatigue failure was determined, and the damage during fatigue was compared.