A new elasto-plastic material model for coated fabric

• Capture the nonlinearities, orthotropic effect in the behaviour of coated fabric.
• Take into account the initial slack in the material behaviours.
• Inelastic deformation is captured.
• A systematic material parameters identification procedure is presented.
• The proposed method can be applied to different kinds of coated fabric.

Tension coated fabric membrane structures have been widely used since the 1960s. One of the contemporary issues in this field is to find an adequate material model for coated fabric which not only can capture the complicated mechanical behaviour of coated fabric, but also has a good performance in computation. This article proposes a new elasto-plastic model for coated fabric. Based on the uniaxial and biaxial tension tests data, the model is proposed which can exhibit the nonlinearities, orthotropic effect and permanent strains in the constitutive behaviour of this architectural material. There are eleven parameters involved in this model in which seven of them are determined from uniaxial tests and the remainder is identified from biaxial tests. The parameters are easy to determine and all have clear physical meaning. The proposed model is then implemented in the finite element code ABAQUS® as a user material subroutine and subsequently validated with the data obtained from biaxial tension tests. The approach can be generally used for different kinds of coated fabric. In this study polyvinyl chloride (PVC) coated polyester fabric is considered. The model shows a good performance in computation and the obtained results are also in good agreement with experimental data. These features enable the proposed model to be used in numerical calculations for tension membrane structures.