Fracture durability of composite–titanium adhesively bonded structures exposed to seawater environment

Abstract

AbstractIn this paper, the fracture durability of composite–titanium adhesively bonded structures exposed to seawater environment was studied experimentally and numerically. The specimens were immersed in artificial seawater at 45°C for different exposure times. The results show that the tensile strength of the specimen aging for 130 days degraded by nearly 55.6%, and the degradation of the mechanical properties of adhesive was not only affected by the moisture but also showed a certain relationship with aging time. Under the condition of saturated moisture, the tensile strength of the specimen still decreased with the increase of aging time. The simulated moisture results of the aging fracture specimen indicate that the moisture of the boundary region of the adhesive layer was mainly absorbed from the adhesive itself, while the moisture of the central region was dependent on the moisture absorption of the composite adherend. Moreover, the moisture absorption of the pre‐crack tip adhesive resulted in different load responses and fracture modes of the aging fracture specimens. Consequently, the fracture toughness of the DCB and ENF specimens aging for 180 days degraded by nearly 66.4% and 33.0%, respectively.