AN IMPROVED IOSIPESCU SHEER TEST FIXTURE

A new Iosipescu shear test fixture design that can be used to perform the test procedure outlined in Test Method for Shear Properties of Com posite Materials by the V-Notched Beam Method (ASTM D 5379) was design ed, fabricated, and tested. The new fixture solves the often reported problems of specimen twisting, variability of results, and differences in measured shear modulus between [0](16), [0/90](4), and [90](16) la minates. Lateral instability of the Iosipescu specimen is explored as the main agent causing the undesirable effects observed with the previ ous fixture design.