Experimental Study on Collective Evolution of Short Fatigue Crack in Low Carbon Steel under Complex Stress State and High Temperature
The collective evolution of short fatigue crack was experimentally studied through differently-notched cylindrical specimens under symmetrical triangle wave load. A simple and feasible method to measure the damage variable was introduced. The crack length and surface damage variable were obtained by the observation system, the measurement software and the Matlab program. The results show that: Grain boundary is the key factor leading to plateau regions phenomena during the increasing process of crack length; the group behavior of short fatigue crack is measurable and can be described by surface damage variable (D); the fitting curves of D-N/Nf present remarkable stage characteristics.
Qunjie Xu, Honghua Ge and Junxi Zhang
L. Wang et al., "Experimental Study on Collective Evolution of Short Fatigue Crack in Low Carbon Steel under Complex Stress State and High Temperature", Advanced Materials Research, Vols. 361-363, pp. 1387-1391, 2012