An electromagnetic NDE technique for measuring the crack ooening displacement of surface fatigue cracks is described. A ferromagnetic resonance probe utilizing yttrium-iron-garnet was used to induce eddy currents in an aluminum plate. The crack opening disolacement of a semi-elliptical fatigue crack evaluated at the surface was measured optically at several values of bending stress on the speci...

Modeling of stress corrosion cracking (SCC) is performed using the combination of the finite element method and the symmetric Galerkin boundary element method. The uncracked structural component is represented with finite elements. The crack is simulated using the boundary element method. The superposition principle is employed for combining two solutions. The equilibrium state for the system o...

In this paper we apply the method developed by Rice [1], of solving for the elastic field of a crack with a front perturbed from some reference shape, to solve the elasticity problems of somewhat circular planar tensile cracks under arbitrary load distributions. The method is based on a known solution for the stress intensity factor along a circular crack due to a pair of wedge-opening point fo...

A B S T R A C T Pump shafts used for power generation are susceptible to fatigue cracking while often in near-continuous operation. Technology based on torsional vibration is under development for condition-based assessment of shaft health. The focus of this paper is on the relationship between a crack, which propagated due to bending loads, and the torsional stiffness of the shaft. An analytic...

Introduction: There are several electromagnetic techniques that can be used for detecting surface-breaking cracks in metals, including potential drop, AC field measurement and eddy current methods. Each method possesses its own advantages and limitations in a specific application. In recent years, the use of microwaves has shown an increasing potential and success as a new technique for non-des...

Abstract-The complete solution for an embedded elliptical crack in an infinite solid and subjected to arbitrary tractions on the crack surface is rederived from Vijayakumar and Atluri’s general solution procedure. The general procedure for evaluating the necessary elliptic integrals in the generalized solution for elliptical crack is also derived in this paper. The generalized solution is emplo...

Ah&met-The boundary element method is used to analyze the ACPD (alternating current potential drop) field perturbed by a semi-elliptical surface flaw in a metallic sheet. The depth of the penetration of the alternating current is assumed to be small as compared to the crack depth. This allows us to adopt the “unfolding” technique developed by Dover et al. [ASTM STP 722, 401-427 (1981)], which r...