不锈钢焊接件低周疲劳固有耗散分析

采用数字图像相关(DIC)技术和红外热成像技术测量了310S不锈钢焊接接头低周疲劳过程中的变形和表面温度场,其中,DIC技术用于观察焊接接头局部变形的不均匀性,红外热成像技术提供样品表面的温度场分布。结果表明:在高应力区域,疲劳失效主要发生在焊接接头处;在低应力区域,疲劳失效主要发生在母材区。通过求解局部热扩散方程计算获得的试件表面的固有耗散分布可用于预测裂纹萌生位置。

Intrinsic Dissipation in Low Cycle Fatigue for Stainless Steel Weldments

DIC and infrared thermography(IRT) were used to measure the deformation and surface temperature fields during low cycle fatigue of 310S with welded joints. DIC was used to observe the nonuniformity of local deformations of the welded joints. IRT provided the temperature field distribution of sample surfaces. The test results show that in high stress areas, fatigue failure occurs mostly in the welded joints; in the low stress areas, fatigue failure occurs mostly in base metal areas. The intrinsic dissipation distribution of specimen surfaces may be acquired by solving the local thermal diffusion equation, which may be used to predict the crack initiation positions.