Mathematical Calibration of the Ring Test with Bulge Formation

Abstract : An available mathematical solution of ring compression with bulge formation was used to calibrate ring test specimens on the basis of constant interface friction factor, m. Calibration curves for the 6:3:2 (Outside Diameter: Inside Diameter: Thickness) and other ring geometries were obtained by mathematical computation and a method was established for calibrating all ring geometries with bulge formation. Calculated calibration curves of the 6:3:2 ring showed very good correlation with experimentally determined interface friction factors, m. The investigation demonstrated that a valid mathematical solution of ring compression can be used for more accurate and less laborious calibration than experimental calibration of ring test specimens.