EFFECT OF SPECIMEN TAB CONFIGURATION ON COMPRESSION TESTING OF COMPOSITE-MATERIALS

Standard Test Method for Compressive Properties of Unidirectional or C ross-Ply Fiber-Resin Composites (ASTM D 3410) for compression testing of composite materials recommends that low-carbon steel or a glass/epo xy composite be used as the tab material, and that the tabs be tapered . However, many details remain unspecified. An analytical study of tab configurations was performed in the present study to determine the ef fect of type of tabbing material and tab-taper angle on the stress dis tributions within a unidirectional composite specimen in compression. More compliant tab materials and shallower tab-taper angles yielded le ss stress concentration in the tab-tip region of the specimen. Therefo re, specimens with these tab configurations should yield higher measur ed compressive strengths since premature failure at the tab tip is les s likely to occur. Although there are relatively few experimental data available for different tab materials and tab-taper angles, those tha t are available show the same trends as predicted by the present analy tical study.