Determination of the Crack Tip Position by Digital Image Correlation during Static and Cyclic Fracture Toughness Tests of Aluminum Alloys

Abstract

Aluminum alloy V-1167RDTV specimens 1 mm thick with a central crack are used to determine the position of the tip of a mode I crack from a strain field distribution during cyclic loading in the course of fatigue crack growth rate tests and during static loading in determining the force characteristics of fracture toughness. When analyzing the displacement and strain distributions at the crack tip, we proposed a technique to measure the length of a statically growing crack to determine critical stress intensity factor K_c for a mode I crack in plane-stress state.