Methodology for Evaluation of Residual Stress Effect on Small Corner-Crack Initiation and Growth

Abstract

The growth behavior of a naturally initiated corner crack under a uniform residual stress field is investigated in this study. A convenient method is proposed to induce and evaluate the uniform residual stress field for a beam-type specimen. Fatigue tests are conducted with a rotary bending fatigue machine to investigate the growth of the corner crack. For this reason, a cylindrical specimen, which is typically used for rotating bending tests, is modified into a beam specimen. The corner crack growth behavior under residual stress is evaluated based on linear elastic fracture mechanics (LEFM) and compared with long through crack data. The test results verify that the corner crack growth under residual stress can be effectively evaluated by LEFM and estimated using long crack data.

Profile and Areal Surface Parameters for Fatigue Fracture Characterisation

“…With an increase in the stress amplitude, the size of the zones changes, the zone with striations decreases and the zone of rupture grows. When testing brittle or quasi-brittle materials, the height of the fracture profile often decreases with increasing crack length as a result of the formation of facets of cleavage or intergranular fracture [ 48 , 49 , 50 , 51 ]. Overall, there were obvious differences in topography for propagation or rupture, particularly the coarser areas.…”

Profile and Areal Surface Parameters for Fatigue Fracture Characterisation

“…With an increase in the stress amplitude, the size of the zones changes, the zone with striations decreases, and the zone of rupture grows. When testing brittle or quasi-brittle materials, the height of the fracture profile often decreases with increasing crack length as a result of formation of facets of cleavage or intergranular fracture [46,47]. Overall, there are obvious differences in topography either for propagation or rupture, particularly the coarser areas.…”