【摘要】 本研究以GH4169合金为研究对象，选用微观单边缺口含裂纹(M-SENT)试样，对不同拘束M-SENT试样模型上下两侧施加不同大小的均布载荷以在裂纹尖端产生不同应力。将该应力作为残余应力引入试样，基于建立的微观多晶疲劳裂纹扩展(MPFCP)模型，研究了残余应力和拘束交互作用对GH4169合金微观疲劳裂纹扩展(MFCP)行为的影响。研究结果表明：应变比R=0时，高拘束下疲劳裂纹扩展(FCP)速率对残余应力的变化更加敏感；R=-1时，不同拘束下FCP速率对残余应力的变化敏感度相差不大。不同拘束试样均存在一个最优的残余应力。高拘束下，R=0时试样的断裂寿命比R=-1时更高。更多还原

【Abstract】 This study used GH4169 alloy as the research object and employed microscopic single-edge notched tension(M-SENT) specimens with cracks. Different magnitudes of uniformly distributed loads were applied to the upper and lower sides of M-SENT specimen models with varying constraints to induce different stress levels at the crack tip. This stress was introduced into the specimens as a residual stress. Based on the established microscopic fatigue crack propagation(MPFCP) model, the influence of the interaction between residual stress and constraint on the microscopic fatigue crack propagation(MFCP) behavior of GH4169 alloy was systematically investigated. The results indicate that at a strain ratio of R=0, the fatigue crack propagation(FCP) rate under high constraint is more sensitive to changes in residual stress; at R=-1, the sensitivity of the fatigue crack growth rate to residual stress variations is relatively similar across different constraint levels. For all specimens with varying constraints, there exists an optimal residual stress level. Under high constraint conditions, the fracture life at R=0 is longer than that at R=-1.更多还原