Local Reinforcement in Notched Fiber Metal Laminates by Bonding Titanium Patch

Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150001, China

Abstract

In order to reduce the stress concentration in notched fiber metal laminate (FML) and improve its damage tolerance, the local reinforcement concept was employed in present paper. Two different reinforced structures were proposed by bonding titanium patch on single side or double sides of the standard glass fiber reinforced aluminum laminate (GLARE). Tensile tests were conducted on these reinforced GLARE, and their mechanical properties were compared for evaluating the reinforced effect of titanium patch, as well as the damage behavior which dominated the mechanical response was analysed later to capture the failure mechanism of the reinforced GLARE. The reinforced effect of titanium patch on mechanical response of GLARE laminate was usually characterized by the improvements of modulus and yield strength, as well as the significant increase of ultimate strain and strength. Cohesive failure and adhesive failure were detected in the adhesive between titanium patch and GLARE laminate, where the adhesive failure corresponded to the weak reinforced case. In addition, the variation of delamination in GLARE laminate was also closely related to the reinforced effect on mechanical response. It is expected that the present investigation can provide technical support for damage tolerance design of fiber metal laminates.