Mechanisms of Wind-Induced Vibration Fatigue Fracture in Large Cylindrical–Conical Steel Cooling Towers

Abstract

Steel cooling towers, with their lighter weight, greater flexibility, and lower damping, are more susceptible to wind-induced damage compared to hyperbolic concrete towers. This study investigates the fatigue fracture mechanisms of cylindrical–conical steel cooling towers (CCSCTs) under high wind loads. Large eddy simulation (LES) techniques determine the three-dimensional (3D) wind load distribution, and a 3D finite element model incorporating elastoplastic material damage is developed in LS-DYNA to simulate the wind-induced collapse process. Results reveal a critical wind speed of 52 m/s, with failure mechanisms driven by interlayer translation and cross-sectional deformation. The stiffening trusses restrict section deformation but concentrate internal forces, while the auxiliary trusses mitigate these forces and provide stability. Key fracture zones include the conical section top (72°, −108°) and tower top (0°) for tension and tower top (±12°) for compression. These findings provide the ultimate limit state (ULS) design criteria for CCSCTs.