Exact stress distribution, crack shape and energy for a running penny-shaped crack in an infinite elastic solid

Abstract

The integral solutions for an axisymmetrical crack propagating at arbitrary speed in an infinite elastic solid are obtained as sums of associated static solutions and stress-waves integrals. For a circular crack running at a constant speed, exact dynamic solutions for crack shape and stress distribution with singularities in the crack plane are obtained in closed forms easily comparable to associated static solutions. The dynamic solution reduces to the static solution at zero crack speed and deviates at speed other than zero. Deviation between dynamic and static solutions is governed by dynamic correction factors which are nondimensional functions of Poisson's ratio and the ratio between crack speed and shear-wave speed. Values of these dynamic factors are obtained for large range of crack speed and deviation can clearly be determined from the results obtained. Exact expressions for dynamic stress-intensity factor and energy functions are also obtained in terms of crack speed.