Effect of temperature variation on the fracture process of double-lap FRP-to-steel bonded joint: an analytical study

•The bond behavior of double-lap FRP-to-steel bonded joint subjected temperature variations is investigated.•A closed-form solutions for the fracture process are derived and validated.•The critical temperature change and bonding length governing the fracture process are derived and discussed. This paper presents an analytical study on the bond behavior of the double-lap FRP-to-steel bonded joint subjected to temperature variation. Closed-form solutions for the full-range bond behavior are derived and validated based on a fully reversible local interfacial bond-slip relation. Besides, finite element (FE) simulations considering the interfacial damage elasticity were conducted to investigate its influence on the interfacial bond behavior. Results show that unlike single-lap FRP-to-steel bonded joint, there exist critical temperature variations and bonding lengths that govern the fracture process of the bonded joint. Compared to the fully reversible bond-slip assumption, considering the interfacial damage elasticity has a significant influence on the bond behavior in the unloading stage in the case of temperature elevation, the load-carrying capacity is not affected provided that the bonding length is sufficiently long. While for a temperature drop, the local damage behavior in the bond-slip relation shows no influence.