The numerical analysis of low cycle fatigue of HTS‐A steel welded joints under combined bending and local compressive loads are implemented using the damage mechanics approach. First, a finite element numerical simulation of the welding process is employed to extract the welding residual stresses, which are then imported as initial stresses in the subsequent fatigue analysis. Second, a multiaxial fatigue damage model including damage coupled elasto‐plastic constitutive equations and plastic damage evolution formulation is applied to evaluate the mechanical degradation of the material under biaxial fatigue loads. Further, the fatigue lives of the HTS‐A steel welded joints are computed and compared with the experimental results from literature. A series of predicted load‐life curves clearly illustrates the variation of fatigue lives along with the combined loadings. Finally, the effects of local compression on accumulated plastic strain and fatigue damage are studied in detail. It is revealed that the local compression induces a damage competition between two critical zones.

中文翻译：

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考虑弯曲残余和局部压缩载荷作用下焊接残余应力和塑性损伤的焊接接头低周疲劳数值分析

采用损伤力学方法对HTS-A钢焊接接头在弯曲和局部压缩载荷作用下的低周疲劳进行了数值分析。首先，采用焊接过程的有限元数值模拟来提取焊接残余应力，然后将其作为初始应力导入后续的疲劳分析中。其次，采用了包含损伤耦合弹塑性本构方程和塑性损伤演化公式的多轴疲劳损伤模型，以评估材料在双轴疲劳载荷下的机械降解。此外，还可以计算出HTS-A钢制焊接接头的疲劳寿命，并将其与文献中的实验结果进行比较。一系列预测的载荷寿命曲线清楚地说明了疲劳寿命随组合载荷的变化。最后，详细研究了局部压缩对累积塑性应变和疲劳损伤的影响。揭示了局部压缩引起两个关键区域之间的损伤竞争。