WAVE SCATTERING OF INTERIOR VERTICAL CRACK IN PLATES AND THE DETECTION OF THE CRACK

The Scattering of waves by an interior vertical crack in a plate has b een studied using the strip element method. A technique for the charac terization of an interior vertical crack is presented. In this techniq ue, two time-harmonic line loads are applied on the upper and lower su rfaces of the plate symmetrically. Additional superimposed oscillation s have been found on the curve of the absolute values of the displacem ent in the region between;he load and the crack. The superimposed osci llations depend on both the length and the depth of the crack. The cra ck length can be determined from the mean value of the peats of the ad ditional oscillations on the upper and lower surface of the plate. The crack depth can be determined from the difference of the additional o scillations on the upper and lower surfaces. Approximate Polynomial fo rmulae for predicting the length and the depth of a vertical crack in an isotropic homogeneous plate are proposed. Numerical examples ale gi ven to demonstrate the present technique. (C) 1997 Published by Elsevi er Science Ltd.