ANALYSIS OF THE BOUNDARY-LAYER AT THE FREE-SURFACE OF A HALF CIRCULARCRACK

The subsurface behavior of the stress intensity factor (K)-solution al ong a half circular crack in half infinite space, due to a mode I poin t load within the crack, was derived in an earlier publication (Intern ationa Journal of Solids and Structures, 1995, 32, 1807-1857). In the present article this behavior is matched asymptotically with the surfa ce solution derived by Benthem (International Journal of Solids and St ructures, 1980, 16, 119-130), yielding a C-1 continuous function along the complete crack front. The resulting boundary layer at the free su rface is made up of a power-law segment linked to a logarithmic functi on. It is shown that its size decreases as the point force approaches the location of the boundary layer, and increases for increasing value s of Poisson's coefficient. An analytical approximation is derived for the K-distribution along the entire crack front for arbitrary locatio ns of the point load and v = 0.3. (C) 1998 Elsevier Science Ltd. All t ights reserved.