Mechanical Properties Analysis And Optimization Of Air-rib Membrane Structure Based On Wind Pressure Distribution Field

As a highly convenient,efficient,and adaptable architectural structure,the inflatable membrane structure has experienced rapid development in our country.With the extensive application of inflatable membrane structures,their types have become more diverse.However,due to its complex structure,it is challenging to determine whether the structural strength meets the requirements.Therefore,it is of great significance to explore a method suitable for solving the wind pressure distribution field of membrane structure to check the strength of structure.This paper takes the widely used vertical arched air-ribbed membrane structure and curved arched air-ribbed membrane structure as the research object.The wind pressure distribution and mechanical performance responses of vertical arched air-ribbed and curved arched air-ribbed membrane structures under different working conditions are solved by computational fluid dynamics and structural finite element analysis.The externally adjustable parameters of the vertical arched air-ribbed membrane structure are optimized according to the variable control method and response surface methodology to reduce the maximum displacement of the tarpaulin.The main research work and conclusions are as follows:This paper compares the mechanical response of vertical arched air-ribbed membrane structure under code load and flow field calculation load.It is found that the calculation result of the wind field is similar to that of the standard shape coefficient.However,the result of wind pressure distribution is more detailed,and the calculation result of the structural load is more accurate.In this paper,the wind pressure distribution of curved arched air-ribbed membrane structure is solved by computational fluid dynamics,and the structural finite element model is established to calculate its mechanical response according to the wind pressure distribution field results.The results show that compared with the vertical arched air-ribbed membrane structure,the maximum displacement of the end face of the curved arched air-ribbed membrane structure is greatly reduced,and the overall maximum displacement is smaller,so the curved arched airribbed membrane structure is better.The tarpaulin stress of the vertical arched air-ribbed membrane structure and the curved arched air-ribbed membrane structure is greatly affected by the internal pressure of the air-rib when the wind load is small,and the stress zone along the air-rib will appear.When the wind load increases,the stress zone along the air-rib gradually disappears,and a large stress area appears in the area greatly affected by the wind load.The air-rib stress is mainly affected by the internal pressure of the air-rib,and its distribution is uniform.However,when the wind load increases gradually,the air-rib root of the two kinds of membrane structures can easily appear as large stress regions.The change of wind direction angle significantly affects the maximum negative wind pressure,and the maximum negative wind pressure will gradually increase with the increase of wind direction angle.When the wind angle is small,the tarpaulin displacement is mainly affected by the wind pressure,and the maximum displacement appears in the windward position.The wind angle increases gradually,the wind suction increases,and the maximum displacement of the tarpaulin changes to the negative wind pressure area.The wind angle has little effect on the stress of the tarp,and the maximum stress appears at the intersection of the oblique air-ribs.In this paper,the four adjustable parameters of the angle of wind ropes laying,air-ribs internal pressure,and initial prestress of wind ropes on the end face and side face are optimized by response surface methodology.Taking the minimum tarpaulin displacement as the optimization objective,the optimal scheme parameters are as follows: The angle of wind ropes laying is 30.8°,the air-ribs internal pressure is 0.3MPa,the initial prestress of the wind ropes on the end face is 378.7Pa,and the initial prestress on the side face is 188.0Pa.In this paper,the flow field analysis method provides a new idea for solving the wind pressure distribution of membrane structure.It optimizes the external parameters,such as wind rope by response surface methodology,which provides a reference for the on-site layout of the air-ribbed membrane structure.