Abstract
Cracks inevitably develop in the pylon structures of suspension bridges due to external forces such as wind loads. Cracks are a primary cause of torsional damage to the key supporting structures of suspension bridges. Therefore, torsional fracture analyses are vitally important for evaluating the safety of bridge structures. In this study, we simplified the tower structure of a suspension bridge as a homogenous cylinder. We then employed the boundary integral equations for a cylinder with edge cracks to investigate the singularity features at the crack tip. The boundary element-based method was subsequently used to divide the boundary into several elements, and different interpolation functions were adopted to compute the stress intensity factor at the crack tip. Torsional stiffness and stress intensity factor calculations were conducted for cylinders with straight and polyline edge cracks. The results were compared with the results reported in the existing literature, and the accuracy and reliability of the calculation method were validated. Finally, the numerical simulation of the torsional fracture behavior of cylinders with edge cracks under various wind loads was conducted. The maximum allowable crack lengths of a cylinder under different wind grades were acquired, further demonstrating the feasibility and practicality of the boundary element calculation method for practical applications in bridge engineering.