Real-Time Aeroelastic Hybrid Simulation Method for Bridge Deck Section Models

A section model test effectively assesses the aeroelastic behavior of long-span bridges in a wind-resistant design. The conventional approach uses springs to support a mass-calibrated physical section model scaled to the similarity principle. Modal damping can also be modeled using sticks soaked in oils. Although this procedure has been successfully applied to most bridges, it involves physical limitations in selecting the model scale and vibration frequencies. Also, certain degrees of time and effort are required for the calibration and modification of dynamic properties in order to achieve precision. This study proposes a new real-time aeroelastic hybrid simulation (RTAHS) approach that eliminates the potential drawbacks of the conventional spring-supported section model test. With this new approach, the aeroelastic force on the physical section model is directly measured using supporting load cells. The equation of motion is solved numerically, and linear electric motors impose the expected movement of the model in a real-time fashion. The hardware of the RTAHS consists of linear electric motors, motor drivers, sensors, and an Ethernet for Control Automation Technology (EtherCAT) based real-time motion controller. The hardware is controlled with three control loops, i.e., numerical integration, time-delay compensation, and PID control of the position. For this study, a series of comparative wind tunnel tests was used to demonstrate the validity of the proposed RTAHS concept.