Effect of Lay-Up Sequence on Relation between Damage and Absorbed Energy in CFRP Laminates Subjected to Falling Weight Impact

Abstract

The relation between damage and absorbed energy in four kinds of carbon/epoxy composite laminates was studied using an instrumented falling weight impact machine. Orthotropic and quasi-isortropic laminates, which were fabricated from unidirectional or plain woven prepreg, were used to investigate the effect of lay-up sequence. The thermal deply technique was applied to determine the extent of delamination and fiber breakage at various impact energy levels. In each kind of laminate, the absorbed impact energy showed a linear relation with the total delamination area and crack area of fiber breakage. No major difference was observed between orthotropic and quasi-isotropic laminates. Thus, the effect of lay-up sequence on the relation between damage and absorbed energy was negligible.