Mechanical and Seismic Response of Pipeline Flange Joints with Solution-Treated Cu-SMA Bolts

Pipeline flange joints often suffer from insufficient energy dissipation and residual deformation under bending loads, compromising the seismic resilience of pipeline systems. To overcome these limitations, this study investigates the application of copper-based shape memory alloy (Cu-SMA) bolts as an alternative to conventional high-strength bolts, aiming to improve both mechanical performance and self-centering capacity. Cu-SMA bolts were fabricated under different solution heat treatment methods and tested under cyclic loading, while finite element simulations and parametric analyses were conducted to evaluate the influence of bolt type and prestrain level. The results demonstrate that optimized Cu-SMA bolts can provide enhanced energy dissipation and significantly reduce residual deformation. Notably, joints equipped with prestrained Cu-SMA bolts exhibited a reduction of approximately 27% in residual deformation compared with conventional bolts. These findings highlight the potential of Cu-SMA bolts for developing resilient and cost-effective pipeline systems in seismic applications.