Real-Time Aeroelastic Hybrid Simulation for Section Model Testing

Section-model testing of long-span bridges typically consists of three types of experiments: force-balance tests, spring-supported tests, and prescribed-motion tests. The spring-supported test is fundamental for identifying vortex-induced vibration (VIV) and flutter instability; however, it captures only the resulting aeroelastic motion without providing information on the underlying wind-induced forces. Conversely, the force-balance test can measure wind-induced forces with or without structural motion, but it cannot represent aeroelastic interaction between the wind and the structural response. In this study, we develop a Real-Time Aeroelastic Hybrid Simulation (RTAHS) system and its application concept using linear motors and real-time controllers. The dynamic modal properties of the bridge deck are modeled numerically, whereas the aerodynamic and aeroelastic forces are physically realized through a scaled section model in the wind tunnel. Real-time wind loads are measured using load cells installed at both ends of the model. The time-delay of the system should be overcome by introducing compensation algorithm. The removal of inertia force is also critical challenge in a low-damping modal system. The proposed RTAHS framework offers several advantages for long-span bridge aerodynamics. First, because the structural parameters are implemented in the numerical model, the experimental setup time in the wind tunnel is significantly reduced. Second, as the section model vibrates, the wind-induced forces are automatically measured in real time, providing deeper insight into aeroelastic phenomena by simultaneously capturing the deck’s dynamic response and the corresponding aerodynamic forces.