EFFECT OF FATIGUE PRE-LOADING ON MIXED-MODE HYDROGEN- ASSISTED CRACKING INITIATION IN HIGH-STRENGTH STEEL

摘要

This work describes experimental evidence of mixed-mode hydrogen-assisted cracking initiation in high-strength prestressing steel and discusses the role of cyclic load history, since fatigue pre-cracking is a basic crack generating technique for posterior stress corrosion testing. To this end, finite deformation analysis of a plane strain crack subjected to mode I loading under small scale yielding was performed. Results of the computational elastoplastic analysis of stress-strain evolution in the vicinity of the crack tip subjected to fatigue and subsequent rising loading are consistent with the experimental fact of anisotropic cracking behaviour of prestressing steel in hydrogenating environment.