Wind-Induced Vibration Response Analysis of Large-Span Double-Tube Reticulated Shell Structure

In this paper, the wind-resistant performance and wind-damaging wind speed of a large-span double-cylinder mesh shell structure of a dry coal shed in Henan Province are investigated by means of large-vortex simulation and structural response calculation. As a flexible system, the large-span space structure is sensitive to the wind load, and it is easily affected by the unsteady strong wind and vibration, which leads to the damage or even collapse of the structure. Therefore, it is necessary to analyze the wind vibration response of the large-span space structure by simulating the generation of unsteady pulsating wind to provide a basis for the study of structural wind-resistant measures. Firstly, the structure is modeled by ANSYS ICEM CFD and SAP 2000 software based on the actual engineering parameters of the dry coal shed, and the unstructured mesh is used for mesh delineation, while the inlet surface is divided into 9 regions to ensure the simulation accuracy. MATLAB software combined with harmonic superposition method and Fast Fourier Transform (FFT) simulation to get the non-stationary pulsating wind, superimposed with the time-varying mean wind will get the non-stationary strong wind in the inlet surface area. Secondly, FLUENT is used to simulate the wind pressure distribution of the structure at five different wind angles under the mean wind pressure and to obtain the wind pressure values on the building surface, so as to determine the most unfavorable wind angle that will cause damage to the structure. The deformation of the structure is analyzed by nonlinear static elastic-plastic analysis (Pushover method) in SAP 2000 and the wind pressure distribution is combined to determine the critical areas of the structure. Finally, the LES vortex simulation method is used to simulate the unsteady strong wind acting on the structure under the most unfavorable wind angle, and the node wind load times are further calculated by obtaining the wind pressure times in the key nodes in the key area. The wind vibration response and other data are analyzed to determine the damage of the structure, and the ultimate wind load capacity is studied to obtain the ultimate wind speed that will damage the structure. Comparison of the simulation results with the actual damage of the structure reveals that the damage is the same, and the model simulation in this paper is considered to be reliable. After the simulation results, it is determined that the 90° angle is the most unfavorable wind angle for the large-span double-cylinder mesh shell structure, and the central region of the structure is the most unfavorable location, and it is determined that the horizontal displacement in the y-direction of the structure is the key to the damage of the structure through the analysis of the displacement time course. The structure reaches the ultimate wind load bearing capacity under the condition of 80 m/s instantaneous wind speed.