Bilinear Constitutive Model Based Theoretical Study on Interfacial Properties of Pipeline Joints Coupling Tension and Temperature

In order to better understand, describe and design the interfacial properties of pipe joints for pipeline structures in actual projects, this paper theoretically investigated the mechanical properties of adhesively bonded pipeline joint interface under simultaneous actions of axial tensile loading and temperature changes based on the bilinear rigid-softening constitutive model. Analytical solutions for interface relative slips, shear stresses and load-displacement relationship, as well as expressions for ultimate loads and effective bonding lengths, were derived. Different failure processes including softening or debonding stages caused by the bonding lengths were discussed, demonstrating the full-ranged interfacial failure of pipeline joints and explaining their stress transfer mechanism, interface crack propagation and ductile behavior. The finite element analysis for certain cases was also checked to coincide with the solutions. This helps establish a theoretical analysis basis for the application of pipeline joints in actual environments with loading and temperature differences.