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An improved two-dimensional finite-difference code for simulating crack initiation, fast crack propagation, and arrest is presented. Compared with the previously available numerical codes, the present one simulates crack processes much more accurately, yielding results which have been found to be in excellent agreement with analytical and experimental findings. The code is applied to the single edge notch and double cantilever beam specimens and preliminary numerical results are discussed.

A finite-difference scheme for treating the dynamic stress field around a crack tip under plane-strain conditions, is proposed. The scheme is initially applied to the case of a crack of constant length which is suddenly opened in an infinite elastic medium loaded by a remotely uniform stress. By this, a numerical solution corresponding to the static state of stress is obtained which is compared with analytic solutions. It is shown that the numerically evaluated strain-energy-release rates are close to values calculated analytically. A modified scheme which presupposes a cuspated crack tip results in nearly the same strain-energy-release rates. Hence the validity of both numerical schemes is confirmed. For the numerical schemes adjusted to handle the propagating crack problem, the results represent a situation which is very close to reality; namely, the crack velocity accelerates up to a stage where propagation continues with a practically constant velocity. This terminal velocity moves from about 0.77 C2 to about 0.57C2 (C2 being the shear wave velocity). The last-mentioned velocity value corresponds to the cuspated crack model.

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