Effect of Surface Treatment on Durability of GFRP Reinforced Aluminum Structure under Hygrothermal Environment

Abstract

The aluminum alloy surface was treated through three different processes. The bonding strength of GFRP-aluminum under hygrothermal environment with different surface treatments was tested and was arranged with the order of anodizing > silane coupling agent > sand blasting. The effects of hygrothermal environment and surface treatment on repair effects were also studied by tensile tests of GFRP and GFRP reinforced aluminum. The results show that the tensile strength, elastic modulus and break elongation of GFRP decrease after wet and heat treatments. After different surface treatments, the initial loads of repaired specimens increase with the order of anodizing > silane coupling agent > sand blasting. The bearing capacities of the specimens repaired by different surface treatments are reduced to different degrees under hygrothermal environment. For sand blasting specimen, the declining of bonding strength of the resin-aluminum is the main cause of the declining of bearing capacity, and damage mainly occurs in the interface. For the silane coupling agent and anodic specimen, damage occurs mainly in the resin-GFRP interface, the mechanical property of resin-aluminum interface is better than that of resin-GFRP.

Keywords

• GFRP
• aluminum alloy
• hygrothermal environment
• surface treatment
• bond behavior