Study of stress waves in crack propagation by the finite-element method

Abstract

1. An algorithm was devised for modeling rapid crack growth and was incorporated into a FEBIK program [9] to solve dynamic FEM problems. 2. The use of this program to study waves of unloading stresses in crack extension showed that the crack tip is a rather unusual source of stress waves. The first stress wave removes the load at the crack tip in all directions and produces a finite discontinuity, the value of which increases roughly parabolically with an increase in initial crack growth rate. In such a case, the first stress wave does not affect the formation of microcracks in front of the main crack. 3. The good agreement between the data obtained and the analytical results shows that the method used to numerically solve dynamic problems for solids with cracks is correct. A shortcoming of the method is the large amount of machine time required. The solution of a problem for one value of\(\mathop a\limits^ \bullet /\mathop a\limits^ \bullet _R\) requires 9 min of machine time on a CDC6600 computer, which corresponds to about 270 min on an ES-1040 computer.