Dynamic stress intensity factor of a cylindrical interface crack with a functionally graded interlayer

This paper presents the dynamic stress intensity factor of a cylindrical interface crack located between two coaxial dissimilar homogeneous cylinders that are bonded with a functionally graded interlayer and subjected to a torsional impact loading. The shear modulus and mass density of the functionally graded interlayer are taken to vary continuously between those of the two coaxial cylinders. The mixed boundary value problem involved is reduced to a singular integral equation with a Cauchy-type kernel in the Laplace domain by applying Laplace and Fourier integral transforms. The expressions for the dynamic stress intensity factor at the crack tips are derived in detail and the results are displayed after solving the singular integral equation numerically and performing numerical Laplace inversions. It is found that the relative magnitudes of the adjoining material properties, the graded interlayer thickness, and the crack length, all have significant effects on the dynamic stress intensity factor. (C) 2001 Published by Elsevier Science Ltd.