EFFECT OF TRANSVERSE-SHEAR FLEXIBILITY ON THE TRANSIENT-RESPONSE OF CRACKED LAMINATED COMPOSITE PLATES TO SUDDEN BENDING

The analytical determination of the time history of stress intensity factors near a through crack in an impacted symmetrically cross-ply laminated composite plate constitutes the main objective of this investigation. Toward the end of removing the shortcomings implied by the use of the classical plate theory when dealing with crack problems, herein the theory of composite plates based upon discarding Kirchhoff hypothesis is employed. It incorporates the effects of transverse shear deformations, transverse normal stress and rotatory inertias and fulfills the tangential conditions on the bounding planes of the plate. As a result, this theory permits the prescription of three boundary conditions on each edge, a fact which renders it very adequate for the problem studied herein. The plate is considered impacted by a bending moment, applied to the surface of the finite crack. By the use of the integral transform technique the problem is reduced to solving a pair of dual integral equations and, further, to the solution of a Fredholm integral equation of the second kind. The numerical illustrations emphasize the effects played by transverse shear deformations and geometric and material properties of the laminate on stress intensity factor history.