Scatter band prediction for fracture toughness of specimens with prior load

This study investigates the warm pre-stress effects under Load–Unload–Cool–Fracture transient with deep-cracked single edge bend specimens of a high strength steel. In the experiment, it has been found that warm pre-stressing increases the apparent overall elastic–plastic fracture toughness KJc_total compared to those of as-received specimens. A simple prediction procedure for fracture toughness of specimens with warm pre-stressing is proposed based on critical plastic zone criterion using fracture parameter superposition rule. It is shown that the increase and the narrower scatter band of fracture toughness of specimens with prior load can be well evaluated within the framework of the Master Curve methodology.