Impact of Sudden Change of Wind Loads on Running Performance of Vehicle on Bridge with Wind Barriers

To investigate the impact of sudden change of wind loads on a vehicle passing through the transition section with wind barriers, a multi-span simply-supported beam bridge of high-speed railway was taken as the research object. Aerodynamic characteristics of the vehicle-bridge system were studied by wind tunnel tests under three wind barrier porosities of 100.0%, 43.5% and 0. Based on the dummy body coupling (DBC) method, a wind-vehicle-bridge coupling simulation model was established. Effects of wind barrier porosities and vehicle operation speeds on the vehicle dynamic responses were analyzed with two types of wind barriers setting (continuously and non-continuously). The results show that aerodynamic characteristics of the vehicle change obviously due to the setting of wind barriers. Compared to the 100.0% wind barrier porosity condition, the drag coefficient of vehicle decreases 87% under the condition of 0 wind barrier porosity. The wind barriers set continuously have obvious wind shielding effects. With the decrease of the wind barrier porosities, the vehicle dynamic responses decrease greatly, and the wheel load reduction rate reaches 53%. With the wind barriers set non-continuously, the sudden change of wind loads has great effects on the lateral and vertical accelerations of the vehicle when it enters and leaves the wind barrier section. The lower the porosity of wind barriers is, the more violent the change of the acceleration response is, but the impact on the lateral force of the wheel axle and the wheel load reduction rate is limited. With the vehicle speed increasing, the responses of acceleration generally increase due to the sudden change of wind loads, in an obviously non-linear trend.