Research On Aeroelastic Response And Aerodynamic Force Of Unidirectional Tensile Membrane Roof Structure

The membrane materials have the characteristics of light weight,large flexibility and small damping,which determine they are sensitive to the wind.In recent years,there have been many cases of membrane roof structure instability and even failure under wind load.The main reason is that when the incoming flow flows through the membrane roof,the roof will vibrate and the flow field around it will be affected.This phenomenon indicates that there is wind-induced coupling effect between the membrane roof structure and the flow field.Because the aeroelastic response and aerodynamic characteristics of membrane roof structure are the most intuitive characterization of wind-induced coupling effect,based on the aeroelastic response and aerodynamic characteristics of unidirectional tension membrane roof,the wind-induced coupling effect between the structure and the flow field is studied by changing the flow field characteristic parameters and structural characteristic parameters.In this thesis,the wind tunnel test combined with the three-dimensional digital image correlation method is mainly used,and the numerical simulation method is combined to study the aeroelastic response and aerodynamic characteristics of the unidirectional tension membrane roof structure under different flow field conditions.The main contents include:(1)Based on the wind tunnel test with 3D digital image correlation method,the3 D reconstruction of the motion state of the unidirectional tension membrane roof structure in different flow fields is carried out,and the aeroelastic response of the unidirectional tension membrane roof structure in different flow fields is obtained.(2)The aeroelastic response time histories of each point on the reconstructed membrane surface are extracted,and the variation laws of vibration frequency and damping ratio of membrane roof under different flow fields are analyzed.(3)The aeroelastic response time history of each point on the model surface is imported into the finite element software for numerical simulation,and the variation law of wind pressure coefficient on the model surface is obtained.The results show that the wind tunnel test combined with 3D digital image correlation method has good 3D reconstruction effect,and the motion of membrane surface in different flow fields basically conforms to the assumption of quasi twodimensional flow.The aeroelastic response of the membrane surface increases with the increase of wind speed and turbulence,and decreases with the increase of pretension.The wind frequency of the membrane surface increases with the increase of wind speed and pretension,decreases with the increase of turbulence,and the first modal damping ratio is always greater than the second modal damping ratio.The average wind pressure of the model front will decrease with the increase of wind speed and turbulence,and increase with the increase of pretension,but the average wind pressure value at the end of the model will not change with the change of the working condition.The wind-induced frequency of the structure in different flow fields is close to the wind pressure frequency of the flow field,which proves the existence of complex unsteady effects.