Improving the aerodynamic performance of Trans-Tokyo Bay Bridge using reliability-based design optimization

The Vortex-Induced Vibration (VIV) phenomenon can cause fatigue damage. Usually, countermeasures are implemented to mitigate the VIV amplitudes. However, its cost is high. Therefore, approaches have been developed to avoid VIV at an early stage of design. Most such studies have focused on avoiding the coincidence of the vortex shedding frequency with the natural frequency of the structure and delaying VIVs by including geometrical changes to the leading and trailing edges in order to divide the oncoming flow. In this study, a new framework is proposed to find the optimal deck cross-sectional shape of Trans-Tokyo Bay Bridge, based on Reliability-Based Design Optimization (RBDO) and aiming to mitigate the VIV effects under uncertainty. Validation of the optimal designs is conducted via Computational Fluid Dynamics (CFD) simulations for different target reliability indices.