Evaluation of Dynamic Stress Intensity Factor of Griffith Crack Using the Finite Element Method

Cracks in elastic media vary significantly, depending on the nature (frequency, direction and magnitude) of the external load as well as the material properties. Therefore, the methods of determining the fracture parameter (Stress Intensity Factor) depends on the crack geometry, which also influences the choice of elements and mesh generation in Finite Element Analysis. In this paper, the Griffith centroid crack is modelled in 3D Finite Elements under harmonic loading. The numerical results of Stress field variables and displacement jumps are compared in order to determine the suitable and reliable method for determining appropriate dynamic SIF of the through-thickness crack. The accuracy and variations of the results were only dependent on the mesh refinement of the isoparametric hexahedral element in the vicinity of the crack tip. The obtained result, which agrees with literature also establishes the validity of the model for both methods of solving mode I fracture dynamic problems, numerically, irrespective of the mesh and element type. For both methods adopted for the determination of SIF, the plane strain condition was satisfied.