Static Mechanical Properties Test And Numerical Analysis Of Planar Tensioned Membrane

Tensioned membrane structures are widely used in stadiums and exhibition centers because of its continuous structure and beautiful external contour.Because of the complexity of its structure,the design of tensioned membrane structure is mainly completed by finite element numerical analysis.The accuracy of numerical analysis results has a great influence on the guiding significance of membrane structure construction.Therefore,it is necessary to compare the influence of different factors on the analysis results in the process of numerical analysis,so as to provide reference for the follow-up analysis of membrane structure.The main research work and conclusions of this paper are as follows:Firstly,a kind of PVDF membrane material was selected as the research object.Based on the energy equivalent method,the unidirectional tensile curve of the film was analyzed to obtain the elastic modulus of the coated fabric.Based on the digital image correlation(DIC),dynamic Poisson’s ratio and shear modulus of membrane materials are measured by unidirectional tensile test and frame shear test.The user-defined material program of ABAQUS software is introduced into the analysis of membrane structure,which provides an important data basis for the subsequent numerical analysis of structure.Secondly,the static loading test of plane tensioned membrane structure is carried out,which mainly considers the factors such as different loading modes and prestressing force,and the corresponding static response and deformation law of the structure are analyzed.The test results show that the initial displacement increment of the plane tensioned membrane structure is the largest in the process of loading test.With the increase of load,the increment of displacement decreases gradually.Load distribution is an important factor affecting the vertical displacement of the membrane.Concentrated loading produces greater vertical displacement than uniform loading.The change of initial prestress mainly affects the initial loading stage.With the increase of surcharge load,the influence of initial prestress on the vertical displacement of membrane surface under the same loading condition is not significant.This is mainly because the in-plane stiffness increased by initial prestress value is much less than that increased by later surcharge load,and with the increase of membrane displacement,the influence of geometric nonlinearity is not significant.The effect of initial prestress is further weakened.In the analysis of membrane structure,the influence of material stiffness change during loading on the structure analysis must be considered.Finally,a series of finite element simulations are carried out for the above-mentioned surcharge tests,considering the influence of element type,network size and boundary form,respectively.Comparing with the test results,the uncertainty of the calculation model is studied,and the suitable finite element modeling and analysis method is put forward.The results show that the change of element type has a certain influence on the numerical analysis in the process of loading test of tensioned membrane structures.Shell element is more accurate in uniform loading test and solid element is more accurate in centralized loading test.However,the change of network size and boundary form has little effect on the results of numerical analysis.Compared with the linear elastic model parameters,the actual dynamic model parameters can better simulate the loading test of the plane tensioned membrane structure.Therefore,it is recommended that the material parameters of the actual dynamic model be adopted by the user-defined material program and the shell element be selected for finite element simulation.