Experimental investigation of the displacement field in a circular disc drilled eccentrically

Abstract

The aim of the present study is to experimentally quantify the role of potential eccentricities of the ring’s hole on the overall displacement field developed in a circular ring under diametral compression. In this context, circular rings, made of PMMA, were subjected to diametral compression using the device suggested by the International Society for Rock Mechanics (ISRM) for the standardized implementation of the Brazilian-disc test. The specimens were circular discs, drilled throughout their thickness, forming either perfect rings (zero eccentricity) or discs with an eccentric hole. The parameters considered included the angle, θ, between the line of centers and the loading axis and the distance, d, between the centers of the disc and the hole. The displacement field developed all over the surface of the specimens was determined using the 3D Digital Image Correlation (DIC) technique. The experimental protocol proved that for small and medium values of the parameter d the influence of eccentricity is described by a linear law independently of the value of angle θ, while for relatively high d-values the phenomenon becomes strongly non-linear.