Inelastic behavior and strength of fiber-metal hybrid composite: GLARE

Off-axis inelastic and fracture behavior of a new type of fiber-metal composite called GLARE 2, a hybrid laminate of unidirectional glass/epoxy laminae (GFRP) and aluminum-alloy sheets, have been examined under static tensile-loading conditions. The classical laminated plate theory (CLT) was applied for describing the off-axis inelastic behavior of GLARE 2 laminate. Irrespective of the off-axis angle, a sharp-transition caused by the yielding of aluminum alloy layers appears in the stress-strain relations. The nonlinearity of the behavior of GLARE 2 after this transition increases more significantly as the off-axis angle becomes larger. The tensile-fracture strength of the GLARE 2 laminate is almost two times as large as that of the monolithic aluminum alloy in the fiber direction, and it is about five times the value of the GFRP in the transverse direction. The anisotropy for the tensile fracture strength of the GLARE 2 laminate can be predicted using the Tsai-Hill theory. For the off-axis angles > 5 degrees, transverse cracks develop in the GFRP layers before the GLARE 2 laminate fractures. A CLT-based model, which takes into account the transverse failure in the GFRP layers to cause an instantaneous degradation of transverse and shear elastic moduli, accurately describes the characteristic deformation behavior of the GLARE 2 laminate. (C) 1997 Published by Elsevier Science Ltd.