THE EFFECT OF STRAIN-RATE AND PRESTRESS ON THE MECHANICAL-BEHAVIOR OFAAL

In the present paper, an experimental study of AAL and AAL(P) (prestre ssed AAL) in the strain rate range from 200 s(-1) to 1300 s(-1) has be en performed. The complete st-ess-strain curves of:he composite under tensile impact were obtained. Results show that the deformation of the composite at high strain rate consists of three parts: elastic deform ation, plastic deformation and residual deformation. The yield stress, ultimate strength and fracture strain of the composite all exhibited rate sensitivity, increasing with increasing strain rate. By applying prestress on AAL, the residual thermal stress existing on the interfac e between aluminium and AFRP is reduced, which results in much higher yielding stress and yielding strain of AAL(P) than those of normal AAL , and the failure strain of AAL(P) is 35% lower than that of AAL. On t he basis of these results, the dynamic behaviour of the composite and a one-dimensional constitutive equation for composite under tensile im pact have been studied. (C) 1998 Published by Elsevier Science Limited . All rights reserved.