Three-dimensional dynamic stress intensity factors around two parallel square cracks in an infinite elastic medium subjected to a time-harmonic stress wave

Abstract

Dynamic stresses around two parallel square cracks in an infinite elastic medium are determined. A time-harmonic stress wave impinges on the two cracks normal to their surfaces. The two-dimensional Fourier transform technique is applied to reduce the mixed boundary value conditions to dual integral equations. To solve the equations, differences of the displacements in the upper square crack are expanded using a double series of functions which are equal to zero outside the crack. Those in the lower crack are also expanded using a similar series. Unknown coefficients in the series are determined by applying the Schmidt method. Dynamic stress intensity factors are calculated numerically assuming that the shape of the upper crack is identical to that of the lower crack.