Advanced Methods of 3D Stress Intensity Factor Assessment

This paper explains and demonstrates how to get stress intensity factors using different evaluation methods for a 3D plate with a straight through-thickness crack. The methods include interaction integrals, J-integral evaluation and energy-release rate. All results from these methods are compared with others, and some useful information about the accuracy and the applicability of these methods obtained. Structural design concepts traditionally use a strength-of-material approach for designing a structure. This method does not consider the elevated stress levels due to the cracks. The presence of such stresses can lead to catastrophic failure of the structure. Fracture mechanics accounts for the cracks or flaws in a structure. The fracture mechanics method to design of structures includes crack size as one important variable, which can anticipate the adverse elevated stress levels and avoid the unexpected collapse accident. Fracture analysis is typically carried out either using the energy criterion or the stress-intensity-factor criterion. The advanced approaches include interaction integrals, J-integral evaluation too. All these method are used to get stress intensity factors for a 3D plate with a straight through-thickness crack in this paper, and the results are compared with others, and some useful information about the accuracy and the applicability of these methods provided.