Dynamic growth of an internal circular crack in a transversely isotropic composite

The dynamic growth of an internal circular crack in a transversely isotropi c composite is investigated using the techniques of Hankel and Laplace tran sforms. The Laplace inversion is carried out through a complete contour int egration. For the crack running at a constant speed, exact dynamic solution s for crack shape and stress distribution with singularities in the crack p lane are obtained in closed forms in terms of anisotropic material constant s and crack speed. Graphite/epoxy and E glass/epoxy materials and an isotropic material are us ed as example materials in calculating the numerical values of the dynamic stress intensity factor and crack shape. The dynamic solution reduces to th e static solution at zero crack speed and deviates at speeds other than zer o. Deviation between dynamic and static solutions is governed by dynamic co rrection factors, which are non-dimensional functions of anisotropic materi al constant ratios and the ratio between crack speed and shear-wave speed. Values of these dynamic factors are obtained for the sample composites for a large range of crack speed. (C) 2001 Elsevier Science Ltd. All rights res erved.