Research On Strengthening Mechanism And Method Of Adhesion Interface Of FRP/Metal Laminates

FRP/metal laminates possesses advantages such as high strength, fatigue- resistant, impact- resistant etc., which is widely used in aerospace and other fields. However, composite panel and metal substrates have great differences in mechanical properties and they are jointed by bonding, which creating a weak interface. All those reasons lead to delaminations in laminates in the course of manufacture and using process, which could impair the structural integrity and mechanical performance of FRP/metal laminates. Therefore, conducting a research on bonding mechanism and process of FRP/metal laminates is of great importance in engineering.First, composite panels and metal substrates have been prepared, creating FRP/metal laminates specimens which have different metal surface roughness. Then conducting a study on the mechanical properties of FRP/metal laminates under tension load. Through those experiments and studies, we have get the relations between metal surface roughness and tension load.Second, low-density tissue of short-aramid-fibers were manufactured to toughen the interface of FRP/metal laminates, and therefore to improve the interfacial properties and structural properties. The toughening and reinforcing effects of short-aramid-fiber toughening method on interfacial and structural properties of FRP/metal laminates were studied by asymmetric double cantilever beam (ADCB) tests, choosing the energy release rate (Gc) as the factor of judgment. ADCB test showed that the Gc of the laminates were significantly improved by short aramid fibers and metal surface roughness.Last, microscopic behavior and toughening mechanism of short-aramid-fiber toughened interface were observed by optical microscopy to explain the toughening effect of short aramid fibers on interface and entire structure.