Paris law constants are commonly obtained with a well established procedure based on standard specimens, notched and pre-cracked. Pre-cracking produces through cracks with stable shapes, nearly straight, similar during all propagation. However, in several situations specimens with corner and surface cracks are recommended. In these cases cracks having significant propagation will continuously m...

The present manuscript focuses on the algorithmic treatment of three-dimensional discontinuities within a purely displacement based finite element setting. In contrast to two-dimensional cracks, the local element based geometric representation of threedimensional crack surfaces is non-unique and thus not straightforward. Accordingly, we compare different crack tracking strategies, one being alg...

Abstract—A model to predict the plastic zone size for material under plane stress condition has been developed and verified experimentally. The developed model is a function of crack size, crack angle and material property (dislocation density). Simulation and validation results show that the model developed show good agreement with experimental results. Samples of low carbon steel (0.035%C) wi...

To clarify effects of crack speed and cross-link density on fracture energy of acrylamide gels, we evaluated the roughness of the fracture surface and measured the fracture energy taking into account the roughness. The fracture energy increases linearly with crack speed V in a fast crack speed region, and the increasing rate of fracture energy with V decreases with increasing cross-link density...

Turbo-generator shafts are often subjected to complex dynamic torsional loadings, resulting in generation and propagation of circumferential cracks. Mode III fatigue crack growth generally results in a fracture surface consisting of peaks and valleys, resembling a factory roof. The fracture surface roughness depends on the material microstructure, the material yield strength, and the applied cy...

quality inspection is an indispensable part of modern industrial manufacturing. steel as a major industry requires constant surveillance and supervision through its various stages of production. continuous casting is a critical step in the steel manufacturing process in which molten steel is solidified into a semi-finished product called slab. once the slab is released from the casting unit, th...

We have developed a low frequency theory for scattering from surface cracks. For the case of halfpenny shaped surface cracks, we are able to relate the reflection coefficient of a Rayleigh wave incident on the crack with the crack size as well as the fracture stress of a sample with the crack in it. Comparisons of the theoretical predictions for the fracture stress with the actual fracture stre...

The object of this work is to calculate the T (transition) matrix for a circular crack in a homogeneous, isotropic, linear elastic medium. The T matrix method is a building block technique for multiple scattering, where the T matrix is calculated for each scatterer separately without prior knowledge of the other scatterers (cracks, inclusions, surfaces, etc.).This means that we solve the scatte...

Based on the theory of elasticity, previous analytical solutions concerning a penny-shaped interface crack employ the derivative of the crack surface opening displacements as the primary unknowns, thus leading to singular integral equations with Cauchy-type singularity. The solutions to the resulting integral equations permit only the determination of stress intensity factors and energy release...