Research on Mean Wind Load and Wind Response Characteristics of Air-Supported Membrane Structures with Rectangular Plane

Inflatable membrane structures are typical wind sensitive structures, and the membrane surface will undergo significant deformation under wind load. Wind resistance is an important factor restricting the development of membrane structures. In order to study the wind load characteristics of inflatable membrane structures with rectangular plane, six different rigid models were designed and manufactured. Three types of landforms, A, B, and C, were simulated using wedges, rough elements, and serrated baffles. The pressure tests of the rigid models with rectangular plane were carried out in the atmospheric boundary layer wind tunnel, and the effects of wind direction, rise-span ratio, length-width ratio and ground roughness on the mean wind pressure distribution were analyzed, and the wind coefficient of the structure was calculated at different wind directions. Based on wind load data obtained from wind tunnel tests, wind vibration response analysis was conducted on a prototype sized inflatable membrane structure with rectangular plane by the finite element software ABAQUS. The membrane surface was modeled using M3D4R elements, and the cable was modeled using T3D2 elements. The mean wind response characteristics of the structure under different wind directions were studied, and the displacement and stress distribution patterns of the membrane surface under wind load were summarized. The locations where the displacement and stress extremes occurred were determined. Finally, a partition scheme for wind load shape coefficient applicable to inflatable membrane structures with rectangular plane was proposed, and suggested values for different partitions were given. The results show that the mean wind pressure coefficient distribution of inflatable membrane structures with rectangular plane is greatly affected by the wind direction and the length-width ratio of the structure, but less affected by the ground roughness. As the length-width ratio decreases, the wind pressure in the upper suction area decreases. As the rise-span ratio increases, the positive wind pressure coefficient in the windward region increases, and the negative wind pressure in the upper suction region decreases. The wind force coefficient of inflatable membrane structures with rectangular plane is the highest at 0° wind attack angle. The inflatable membrane structure with rectangular plane has significant deformation on the windward surface and top at 0° and 45° wind attack angle, while the deformation on the windward surface is significant at 90° wind attack angle and the deformation on the top is relatively small. At 0° and 90° wind attack angle, the stress in the protruding parts connecting the two sides and the middle of the structure is relatively high. At 45° wind attack angle, there are obvious folds and stress concentration at the corner of the windward surface. The maximum displacement and stress are observed at 0° wind attack angle, while the minimum displacement and stress are observed at 90° wind attack angle. It is recommended to use 5 zones for the wind load shape coefficient of inflatable membrane structures with rectangular plane at 0° and 90° wind attack angle, and 7 zones at 45° wind attack angle. The zoning wind load shape coefficient at 0° and 90° wind attack angle is significantly affected by the rise-span ratio, while at 45° wind attack angle it is significantly affected by the length-width ratio.