Theoretical analysis of the effects of relative crack length and loading angle on the experimental results for cracked Brazilian disk testing

Based on the closed-form expressions of the stress intensity factors for a central cracked circualr disk, Four cri-or transfer functions of the stress intensity factors were introduced in order to analyze the effect of the relative crack length and the error of loading angle on the experimental results for Brazilian disk testing. The analyzed results show that the precision of K-I and K-II are relevant on the relative crack length and the error of loading angle. Further analysis show that the error of loading angle Delta theta has a significant effect on the errors of K, and K-II Lindcr mixed-mode loading condition, but Delta theta has nearly no effect on the error of K-I under pure mode I loading condition and smaller effect on that of K-II under pure mode 11 loadino condition. Finally, the recommended range of the relative crack length is between 0.4 and 0.6. (C) 2007 Elsevier Ltd. All rights reserved.