A NOVEL SPECIMEN GEOMETRY FOR DOUBLE SHEAR CREEP EXPERIMENTS

A new specimen geometry has been developed to reduce the stress concentrations at the ends of the gage section in double shear creep specimens. The purpose of the geometry is to reduce the tendency for crack formation at the gage section ends when testing creep brittle materials. A comparison of creep data indicates that the sharp corners at the ends of the gage sections of the conventional geometry has a negligible effect on the steady-state creep behavior. The results also suggest that, when a nonuniform gage section is used, the stresses redistribute during primary creep such that steady-state flow is driven by the mean shear stress over the entire gage section.