|Following ASTM D 5379 the Iosipescu shear test induces a state of pure shear at the specimen mid-section by applying two counteracting moments. The two opposing sections of the apparatus can be moved in opposite directions. A composite specimen is gripped at the rim of each side and the force is induced via four points. Ninety-degree notches are machined in the specimen and determin the area of failure. The central region is assumed to be in pure shear.
For determining shear strength using Iosipescu, there are some uncertainties in the test results:
On the other hand, the Iosipescu method provides an inexpensive and flexible way of testing shear strength. Varying laminate orientations can be tested easily using only one testing method.