CHARACTERIZATION OF A HORIZONTAL CRACK IN ANISOTROPIC LAMINATED PLATES

A technique is presented for the characterization of a horizontal crack in an anisotropic laminated plate. In this technique, a distributed harmonic load is applied on the plate surface and then moved along the plate surface. The displacement in the thickness direction of the plate at the central point of the distributed load is computed by using the strip element method. The crack length is approximately determined from pattern change of the responses, which is found to have significant change when the load moves over the crack tips. The crack depth is determined from the intervals of the oscillations of the responses in the region between the two crack tips; the intervals are found to be dependent on the crack depth and less dependent on the crack length. Approximate polynomial formulae of degree three for predicting the depths of horizontal cracks in isotropic homogeneous and anisotropic laminated plates are also proposed.