An experimental investigation into dynamic fracture: I. Crack initiation and arrest

Abstract

Problems of dynamic crack propagation are examined experimentally in a series of four papers. In this paper, the first of this series, crack initiation and arrest are investigated in thin sheets of Homalite-100. It is found that as the rate of loading increases to as high as 105 MPa/sec, the stress intensity factor required to initiate crack growth increases markedly. Crack arrest resulting from a simulated pressurized semi-infinite crack in an unbounded medium was found to occur abruptly. There was no continuous deceleration and the crack always stopped at a constant value of the stress intensity factor, which value was lower than the stress intensity factor required for quasi-static crack growth initiation.