氩弧焊接接头疲劳寿命预测

Fatigue Iife Prediction in Argon-arc Welded Joint

对TA15钛合金板材进行氩弧焊对接焊后,加工成光滑疲劳试件进行R=0.5,0.06的高周疲劳SN曲线测试。试验后对试样断口进行扫描电镜(SEM)分析发现,疲劳源大多位于焊接区域的气孔或夹杂等焊接缺陷处。以焊接处微观结构缺陷尺寸作为初始裂纹尺寸,采用基于裂纹闭合的全寿命预测模型,以焊接区域不同位置的长裂纹扩展速率曲线作为基线,利用J.C.Newman的FASTRANII软件对焊接接头试件的疲劳寿命进行预测,发现采用焊缝边缘处的长裂纹扩展曲线预测结果与试验结果吻合较好。

Smooth fatigue specimens of welded joint were made by using argon-arc welding. The material used was TA15 titanium sheet. High cycle fatigue tests were carried out at R=0.5,0.06. SEM analyses found that most of the initiation of cracks at defects of the welded joint. Fatigue life prediction from the initial crack size to failure based on long crack propagation at different zones of welded joint was made by using J.C.Newman′s FASTRAN II code. It was found that predicted results were agreed well with the experiment data by using long crack propagation base line at boundary of the welded joint.