Solutions of stress intensity factors for external and internal unpressurized and pressurized surface cracks in internally pressurized thick-walled reactor pressure vessels are determined directly by a three-dimensional displacement-hybrid finite element method. The finite element method is based on a rigorous modified variational principle of the total potential energy, with arbitrary element ...

We consider the plane elasticity problem of two asymmetrical edge cracks emanating from an elliptical hole in two-dimensional decagonal quasicrystals (QCs) under remotely uniform tensile stress. A complex variation method QCs is developed to solve containing defects. The analytical solutions for stress field and intensity factors near crack tip are expressed by using a conformal mapping techniq...

This is the ®rst in a series of two papers generated from a study on net-section-collapse (NSC) analysis of circumferentially cracked pipes. In this paper (part I), a generalized NSC method is presented to predict the maximum moment of a circumferentially cracked pipe with a variable-depth internal surface crack subject to combined bending and tension (pressure-induced) loads. Two sets of equat...

In this paper, stress-intensity factor solutions are presented for an embedded elliptical crack in a round bar subjected to tensile load. The factors (SIF) tabulated form and were obtained from three-dimensional finite-element analyses of configuration. provide the as function three dimensionless parameters representative size, aspect ratio flaw its relative position cross section. cover ranges...

There are few experimental results to date describing the crack-propagation threshold behavior of short fatigue cracks under multiaxial loading conditions. To address this need, in the present study, the variation in mixed-mode, high-cycle fatigue-crack growth thresholds with crack size and shape are reported for a Ti-6Al-4V turbine blade alloy, heat treated to two widely different microstructu...

There are few experimental results to date describing the crack-propagation threshold behavior of short fatigue cracks under multiaxial loading conditions. To address this need, in the present study, the variation in mixed-mode, high-cycle fatigue-crack growth thresholds with crack size and shape are reported for a Ti-6Al-4V turbine blade alloy, heat treated to two widely different microstructu...

Abstract-An alternating method, in conjunction with the finite element method and a solution for multiple coplanar elliptical cracks in an intinite solid, is used to determine stress intensity factors for semi-elliptical surface flaws in cylindrical pressure vessels. The solution technique for multiple cracks in an infinite body has recently been developed by the prese.nt authors which implemen...

This paper explores theoretically the possibility of using caustics, formed in the ultrasonic field diffracted by defects, as an approach to the inverse scattering problem, The case of crack-like defects is considered in detail, using the geometrical theory of diffraction. The involute of the far field caustic reproduces the projection of the crack edge in the incident beam direction, for a pla...