Creep-cyclic plasticity and creep-fatigue damage interaction of a welded flange are studied considering both the thermo-mechanical load and the welding residual stress (WRS). The presence of WRS was found to have a minimal effect on the shakedown and ratcheting interaction curves, though the stress distribution changes considerably in the presence of WRS. The effect of WRS is predominant for the initial cycles after which it relaxes so that at steady state the creep-cyclic plasticity response is similar with and without the WRS. Depending on the magnitude and sign of the WRS at different locations within the weldment, it has both a detrimental and beneficial effect on the creep-fatigue life. Investigations are carried out using the Linear Matching Method (LMM), which is further modified to assess the creep-fatigue damage considering both transient cycles and the WRS. Results show that the presence of aweldment induces tensile and compressive stress/strain at it's vicinity, which substantially influences the creep and fatigue damage. The presence of WRS further complicates this. For all the combinations of damage calculations undertaken, with and without the consideration of WRS or mean strain, the order of elements with maximum damage differed.

考虑到热机械载荷和焊接残余应力 (WRS)，研究了焊接法兰的蠕变循环塑性和蠕变疲劳损伤相互作用。发现 WRS 的存在对安定和棘轮相互作用曲线的影响最小，尽管在 WRS 存在下应力分布发生了相当大的变化。WRS 的影响在初始循环中占主导地位，之后它会松弛，因此在稳态下，使用和不使用 WRS 时蠕变循环塑性响应是相似的。根据焊件内不同位置的 WRS 的大小和符号，它对蠕变疲劳寿命既有不利影响，也有有利影响。使用线性匹配方法 (LMM) 进行调查，它被进一步修改以评估考虑瞬态循环和 WRS 的蠕变疲劳损坏。结果表明，焊缝的存在会在其附近引起拉伸和压缩应力/应变，从而显着影响蠕变和疲劳损伤。WRS 的存在使这进一步复杂化。对于所有进行的损伤计算组合，无论是否考虑 WRS 或平均应变，具有最大损伤的单元的顺序都不同。