Modal Evolution and Prediction of Wind Pressure Field of Long-Span Roof Structures Considering Interference Effects

Dynamic Mode Decomposition (DMD) is a powerful data-driven method whose core strength lies in its ability to extract dominant dynamic modes directly from data, revealing the key to system physical mechanisms and dynamic evolution. Therefore, this study uses wind tunnel test data as the foundation, systematically investigates the modal characteristics of the wind pressure field on the surface of large-span cylindrical latticed shell structures under interference conditions and their short-term prediction capabilities by applying the DMD method. By analyzing the wind pressure coefficients under different typical wind direction angles, it was found that the existence of the interference model significantly altered the wind pressure distribution characteristics on the surface of the target structure, with the shielding effect being particularly pronounced at a wind direction angle of 180 ° . The study employs the DMD method to perform modal decomposition and reconstruction of wind pressure fields, investigating the influence of mode order on reconstruction accuracy. The results indicate that the reconstruction error relatively decreases as the number of modes increases. Furthermore, a reduced-order model was constructed based on the dominant modes to achieve short-term prediction of the wind pressure field. It was found that the prediction performance was better in the area close to the incoming flow, and the prediction effects varies under different wind direction angles, with relatively larger error at a wind direction angle of 90 ° . By combining the numerical simulation results, this analysis reveals the mechanism of the interference effect on the flow field structure under different wind direction angles. This study verifies the feasibility and effectiveness of the DMD method in the analysis of wind pressure distribution and short-term prediction of large-span spatial structures under interference conditions, which have significant research significance for the wind-resistant design of large-span spatial structures.