Abstract
The time variation of fracture mechanics parameters may be computed by the finite element method. However, this method requires a large computer time and is not conveniently used in material testing. In a previous paper, the authors derived a simple formula for calculating the dynamic stress intensity factor of an elastic three-point bend specimen subjected to impact loading. In the present paper, the formula is extended to include large scale yielding by introducing a plastic zone correction, and a simple method is proposed for evaluating the J^^-integral, a dynamic fracture mechanics parameter which is an extension of the J-integral and includes the effects of inertia force etc. Numerical examples are presented to demonstrate the practical applicability of the method. It is shown that a reasonable accuracy is obtained by the present method as compared with the elastic/viscoplastic finite element computation; and the CPU-time is within 1% of the finite element method. The limitation of the present method is also discussed.
