Study on stress relaxation of membrane structures in the prestress state by considering viscoelastic properties of coated fabrics

• The stress relaxation of membrane structures at the prestress state is studied.
• The generalized Maxwell model is used in the structural analysis process.
• The parameters of material model are determined by stress relaxation tests.
• The stress relaxation behavior of a saddle membrane surface is analyzed.
• The validity of numerical analysis is examined by tests of cruciform model.

This paper studies the stress distributions of tensile fabric structures in the prestress state over time to investigate the stress relaxation behavior. To describe the viscoelasticity of coated fabrics, the viscoelastic constitutive law is established based on the generalized Maxwell model. The parameters in the constitutive equation are determined through uniaxial and biaxial stress relaxation tests. The initial state of the actual equilibrium configuration after construction is obtained by means of elastic analysis. By introducing the incremental viscoelastic constitutive equation of coated fabrics into FEM analysis, the stress distributions of equilibrium configuration over time are estimated. A program is developed and the numerical example of stress relaxation analysis of a saddle membrane surface is given. The validity of the suggested analytical method is examined by comparing the numerical results with experimental data of model tests.