AN EXPERIMENTAL INVESTIGATION OF THE SHEAR STRENGTH TEST METHOD FOR CFRP LAMINATES

摘要

The in-plane shear properties of prepreg and woven QI-CFRP laminates were evaluated by using Iosipescu and V-notch rail shear test methods at room temperature. In untabbed Iosipescu tests, premature fracture occurred at the edges of the specimen due to stress concentrations. To prevent the premature fracture, metal tabs were bonded on the surfaces of Iosipescu specimens. The metal-tabbed Iosipescu specimens fractured near the gage area of the specimen. However, observation indicated that the final fracture occurred away from the gage area by out-of-plane buckling of the outermost + -45 deg plies. In V-notch rail shear tests, the final fracture occurred similarly to metal-tabbed Iosipescu tests. However, the maximum shear stress was lower than that obtained by metal-tabbed Iosipescu test. The difference would be attributed to the differences of the stabilities against out-of-plane buckling.