The investigation of sea water effects on demage of behavior of adhesive joints in composite materials

In this study, the failure behaviors of adhesively strap joints in composite plates which were stayed in the sea water were analysed with experimentally. The eight layered woven glass fiber/epoxy composite plates were used as adherend and epoxy based adhesive were used as bonded material. The patch and adherend were used as same composite plates. In the producing of specimens, the [0°]8 layer sequence were used for composite plates of adherent and [0°]8, [15°]8, [30°]8, [45°]8 layer sequences were used for patch. The lap length of adhesively joints were chosed as 20 mm, 30 mm and 40 mm and the adhesively joints were realised with single and double lap. Then the specimens were stayed in sea water 9 month, 12 month, 15 month and 18 month. The failure loads of the samples which were stayed in the sea water were compared with the failure loads of dry samples. As a results of study, it has been observed that the failure loads were decreased with stayed in the sea water. It has been determined that the greatest reduction in damage loads occurs in specimens with a 20 mm trap length stored in seawater for 18 months.