THE INFLUENCE OF SPECIMEN SIZE ON THE SURFACE STRESS-DISTRIBUTION INDUCED BY INDENTATION TESTING

The stress state in an elastic cylindrical coupon of finite dimensions on a rigid, frictionless foundation under axisymmetric contact loadin g is studied The axisymmetric stress analysis is devoted to an investi gation of the effects of the free surfaces of the plate on the surface radial tensile stress field, which is particularly important for an a ssessment of crack initiation in brittle materials. Attention is focus ed on cases where the ratio of plate thickness (h) and plate radius (w ) to contact radius (a) fall in the range 0.5 < h/a < 10, and 1 < w/a < 5, respectively, which is the region of both experimental and theore tical interest. (C) 1997 Elsevier Science Ltd.