非稳态蠕变裂纹断裂力学参量的工程分析方法

THE ENGINEERING APPROACH FOR ANALYSIS OF CREEP FRACTURE PARAMETER UNDER NON-STEADY CREEP CONDITION

推广弹塑性断裂力学的 ＥＰＲＩ．工程分析方法用于蠕变裂纹分析，建立了弹性－幂律蠕变 材料裂纹体在非稳态蠕变条件下的Ｊ积分、Ｃ积分和载荷线位移的工程估算公式．以受均匀 拉伸的平面应变单边裂纹板为例，对若干种典型的时间相关载荷，与有限元解进行了比较、结 果表明。

There exists neither accurate solution nor universal engineering one for the creep fracture parameter of the elastic-power-law creep cracked body under unsteady creep condition. Establishing an EPRI engineering approach for the elastic-plastic fracture mechanics in the creep crack analysis, this paper has proposed the engineering estimation formulae for the transient crack tip J integral, C integral, far-field J integral and load-line displacement for the unsteady creep. The proposed engineering approach is validated by the finite element method for the single-edge-cracked plate of plane strain subjected to the time-dependent tension. The results show that in the whole range from the small-scale creep to the steady one, the proposed engineering solutions are well consistent with those by finite element method with the maximum deviation about 0.5%. Therefore, the proposed engineering approach exhibits a higher accuracy, at least from the engineering application viewpoint.