中文摘要：

为了解镍基合金焊接接头焊缝成形系数及强度组配对裂纹尖端力学特性的影响,借助有限元数值模拟手段,分析了焊缝成形系数及不同组配条件下裂纹尖端力学特性。低组配下,裂尖Mises应力、等效塑性应变及J积分均随着成形系数的增大而增大;等组配下,裂尖力学特性不变;高组配下,裂尖Mises应力、等效塑性应变及J积分均随着成形系数的增大而减小。随着组配比的增加,裂尖Mises应力随之增加,裂尖等效塑性应变和J积分逐渐减小。研究结果表明,强度组配对裂尖力学特性有较大的影响,焊缝成形系数对裂尖力学特性影响较小。

英文摘要：

To understand the effect of form factor and strength matching on mechanical properties of the crack tip in weld zone for Nickel-based alloys, systematic analysis was conducted by finite element numerical simulation In low strength matching, the Mi- ses stress, equivalent plastic strain and j-integral of the crack tip all increase with the form factor of the weld. With the same strength matching,the mechanical properties of the crack tip are not changed. In high strength matching,the Mises stress, equivalent plastic strain and j-integral of the crack tip decrease with the form factor of the weld. With the increase of the strength matching ratio, the Mises stress of the crack tip increases, while the equivalent plastic strain and the j-integral decrease gradual-ly. Results show that the strength matching has larger effects on the mechanical properties of the crack tip than the form factor of the weld.