A compact mixed-mode (cmm) fracture specimen

Abstract

A practical, compact mixed-mode (CMM) fracture specimen, which can be used for any combination of mode-I and mode-II stress intensities, is described. The loading system, which is suitable for high temperature testing, is also described. The specimen can be used for mixed-mode testing under static, fatigue, creep, or creep/fatigue conditions. The stress-intensity factors ( KI and KII) for the complete range of loading conditions have been obtained by finite element and photoelastic methods. Nodal displacement, stress, and contour integral methods, using the finite element results all gave practically the same stress intensity factors. These were in reasonably close agreement with the results obtained using shear stress distributions obtained from the photoelastic tests.