Characterization of Mismatch Constraint Effect for the Central Crack Plate under Biaxial Loading

Abstract

The effects of biaxial loading and creep mismatch on creep fracture parameter C(t) and constraint effect are investigated for the plane strain central crack plate. The studied biaxialities in this paper are limited to the range of [-1,1]. Based on the three-term asymptotic solution for creep crack tip field, the higher-order terms coefficient parameter A2(t) is introduced to characterize the creep mismatch constraint effect. The impacts of loading level on the parameter A2(t) for different biaxialities and creep mismatch factors are also examined in this paper. The result shows that the steady creep fracture parameter C* decreases with the increments of mismatch factor and biaxiality B. The creep constraint parameter A2(t) is insensitive to loading level for the creep mismatch crack plate under biaxial loading. The steady creep constraint parameter increases with the increments of biaxialities and decreases as m increases, which indicates the higher under-match plate with higher biaxiality has higher creep constraint effect.