Study On Anti-bursting Properties Of Coated Fabrics

Coated fabrics are the main component of membrane structure and they are vulnerable to breakage due to external impurities in daily use,which leads to the reduction or even instability of the bearing capacity of membrane structure.The mechanical properties of membrane materials are mainly in-plane tests such as tension,tearing and shearing,while the bursting tests of coated fabrics are less.It is difficult to obtain the test data directly without the test equipment.As a flexible composite material,the mechanical properties of coated fabrics are characterized by non-linearity and anisotropy due to the interaction of braiding technology and component materials.Therefore,it is necessary to take these characteristics into account in the failure analysis of coated fabrics under bursting.In this paper,the bursting resistance and failure criteria of coated fabrics are discussed by means of experimental,numerical analysis and theoretical derivation.The main research contents and conclusions are as follows:(1)Mechanical properties with out-of-plane bursting of coated fabrics were studied.Two kinds of fixtures were designed according to the characteristics of coated fabric.Bursting test of several kinds of coated fabric were carried out combined with DIC(Digital image correlation)technology.The force-displacement curves during the bursting process and strain distribution of membrane surface were obtained.The effects of bursting rate,punch shape,cutting direction and material type on the bursting properties were analyzed.The failure mechanism of coated fabric under different punches was studied emphatically.(2)Numerical simulation of coated fabric bursting.ABAQUS software was used to analyze on bursting of coated fabrics.Two kinds of methods based on linear elastic anisotropic constitutive relation and *Fabric keywords were considered respectively.The bursting force-displacement curves and strain distribution were obtained.It was found that the curves obtained from *Fabric keyword were in good agreement with the experimental curves,which could reflect the non-linear characteristic of coated fabrics.And the strain distribution obtained from simulation results was also in good agreement with experimental results.(3)The strength criterion of coated fabrics was studied.The failure criterion of coated fabrics bursting was expressed in the form of strain and strain respectively.Several common anisotropic strength criteria were discussed.Based on Tsai-Wu criterion,a modified strength criterion was proposed.It was found that process of coated fabric bursting under flat-nosed and hemispherical-nosed punches could be well predicted by the new revised criterion.The stress form of failure criterion under bursting load was obtained by predicting and verifying of VUSDFLD subroutine.