摘要
Fatigue behavior of AZ31B magnesium alloy electron beam welded joint undergoing cyclic loading was investigated by infrared thermography. Temperature evolution throughout a fatigue process was presented and the mechanism of heat generationwas discussed. Fatigue limit of the welded joint was predicted and the fatigue damage was also assessed based ontheevolution of the temperatureand hotspot zone on the specimen surfaceduring fatigue tests. The presented results show that infrared thermography can not onlyquicklypredict the fatigue behavior of the welded joint, but also qualitatively identify the evolution of fatigue damage in real time. It is found that the predicted fatigue limit agrees well with the conventionalS-Nexperimental results. The evolution of the temperatureand hotspot zone on the specimen surface can be an effectivefatigue damage indicatorfor effectiveevaluationof magnesium alloy electron beam welded joint.
采用红外热像法对循环载荷下AZ31B镁合金电子束焊接接头的疲劳行为进行研究。对试件在疲劳试验中表面温度演变规律和产热机制进行分析,并在此基础上对其疲劳极限进行预测,同时通过分析试件表面温度和热点区域的演变规律对其疲劳损伤进行定量评估。结果表明:采用红外热像法不仅能够实现对镁合金电子束焊接接头疲劳极限的快速预测,而且可以对其疲劳损伤进行实时定量监测。镁合金电子束焊接接头疲劳极限预测结果同传统S-N试验结果保持一致。试件表面温度以及热点区域演变可作为评价镁合金电子束焊接接头疲劳损伤的有效依据。
基金
Project(51305292)supported by the National Natural Science Foundation of China
Project(20105429001)supported by the National Aeronautical Science Foundation of China
