Dynamic Finite Element Analysis of Cracked Bodies with Stationary Cracks

Abstract

A dynamic finite element analysis utilizing a simple singular element (obtained from a degenerate eight-node isoparametric element) was used to investigate three elastodynamic problems with stationary cracks. The first problem, involving a centrally cracked rectangular bar (subjected to uniaxial tension with Heaviside-function time dependence) was analyzed in order to compare the present simple singular element formulation with previously developed higher order singular element formulations. In the second problem, a three-point bend specimen of birefringent material (under drop-weight testing) was analyzed to compare the dynamic stress intensity factors obtained from the present analysis with the experimental counterpart. Excellent agreement between the present results and those from previous investigations (both numerical as well as experimental) demonstrates the capability and reliability of this simple singular element formulation for solving fracture dynamics problems with stationary cracks. The third problem, involving a three-point bend specimen of A533B steel, suggests a potential application of the present method in instrumented impact tests.