CRACK TIP OPENING ANGLE RELATED TO THE PARIS TEARING MODULUS IN A533B STEEL

摘要

Crack tip opening angles (CTOA) were measured on the side surfaces of three point bend test pieces of A533B steel. Measurement of the angle was facilitated by printing square grids with a spacing of 127 micrometres on the side surface through which crack propagation occurred. Sequential photographs of the grid during testing show the appearance of the surface crack and the subsequent development of the CTOA. The simultaneous determination of the Jr curve and the CTOA allowed a correlation between the CTOA and the Paris Tearing Modulus, T. The correlation is in agreement with the calculation of Ogasawara and Okamura (1983) for the plane stress CTOA which should be appropriate for surface measurements.