An analytical assessment of using the losipescu shear test for hybrid composites

A theoretical evaluation of the applicability of the Iosipescu test (v-notch shear test) has been conducted for hybrid composites having unidirectional glass and carbon fiber tows that are intimately mixed, instead of being arranged in separate lamina. The v-notch specimen of hybrid composites was analyzed using the finite element method based on the fiber tow properties to evaluate the effect of varied microstructures in hybrids on the shear stress and strain states. The analyses were conducted to determine how closely the test would meet the requirement of an ideal shear test that there should be pure and uniform stress and strain distributions in the test region. The study shows that, theoretically, the v-notch test can be used to determine the shear modulus of the hybrid composites studied when it is correctly used. However, practically, premature failures caused by the stress concentrations near the notch roots can make the test undesirable for determining the shear strength of the hybrid composite. (C) 2002 Elsevier Science Ltd. All rights reserved.