Enhancement in the Numerical Simulation of Textile Fabrics by Local Calculation of Stress‐Ratio‐Dependent Material Parameters

Abstract

AbstractIn the structural analysis of tensile membranes, the linear elastic model is still a favorable choice for design engineers due to its simplicity and straightforward interpretation of parameters. However, it is well known that such an over simplification of the complex behavior leads to inaccurate or even false response in numerical simulations. In this work, the linear elastic model together with the hyperelastic orthotropic material model proposed for geometrically nonlinear simulation of tensile surfaces is considered as the basis for a new numerical approach leading to more accurate structural simulations. The nonlinear model is able to provide a more precise description of fabric materials and becomes a competitive candidate for realistic structural analysis with only 3 material parameters. In the proposed procedure, the material parameters are estimated based on the stress ratios encountered in structural simulations. Therefore, the material properties are initially identified for each loading scenario of the load‐driven biaxial experiments. This results in a number of sets of different stress‐ratio‐dependent material parameters following the experimentally applied load ratios. In a second identification step, an iterative simulation procedure is employed in which, according to the locally obtained stress ratios in the discretized structural problem, the associated parameter values at each material point will be updated. For new stress ratios that lie between those applied experimentally, an interpolation scheme is implemented that approximates the parameter value accordingly. The iterative simulation is repeated until the total change in the updated parameters at all points becomes insignificant. By employing the proposed method, it is shown that the linear elastic model will be able to more accurately represent the complex behavior of textile membranes.