Experimental and numerical analyses of mixed mode crack initiation angle.

摘要

The main objective of this study is to predict the crack initiation angle for mixed mode fracture using both photoelasticity and numerical techniques. The FE code "ANSYS" is used to estimate the SIF numerically. The estimated value of the SIF is going to be incorporated into crack initiation criteria to predict the crack initiation angle. Six criteria were considered in this analysis and these are the maximum tangential stress (MTS) criterion, the minimum strain energy density (S) criterion, the maximum dilatational strain (T) criterion, the maximum triaxial stress (M) criterion, the modified MTS criterion (M.MTS) and the (R) criterion. A Polycarbonate sheet of 3mm thickness was used for manufacturing single edge crack specimens. All specimens have the same crack length but different angles of inclination namely, 0°, 10°, 20°, 30° and 40°. In the experimental analysis, the specimens were loaded until the crack initiated and the angle is measured to validate both techniques. A new model based on numerical results is proposed for estimating the geometric correction factor Y for an inclined edge crack panel. (Abstract shortened by UMI.)