Stress Intensity Factor Solutions for CTS Mixed Mode Specimen

Abstract

The Compact Tension Shear (CTS) specimen is used to study fracture and fatigue under mixed mode I/II loading conditions. The K solution available in literature was developed for fracture studies and does not consider the effect of crack deflection. The aim of present work is to develop KI and KII empirical solutions for cracks with different crack lengths, loading angles and crack orientations. A total number of 1120 cracked geometries were studied numerically with the finite element method and analytical solutions were fitted to the numerical predictions. An average difference of 0.53 % was found between numerical predictions and the analytical solution proposed for KI. For KII the difference is higher, but the equivalent stress intensity factor showed a difference of only 1% because KII is lower than KI. Experimental work was developed to study fatigue crack growth in CTS specimens. The cracks always adopted a direction approximately normal to loading direction, i.e., tend to propagate under mode I.