Numerical study of the mechanics of indentation bending tests of thin membranes and inverse materials parameters prediction

Abstract

Indentation bending tests are an important testing method for thin rubber-like materials. The choice of material laws in finite element (FE) simulations of the test directly influences the accuracy of the numerical model and material properties predicted through inverse FE modelling. In this work, the effect of using a linear elastic or hyperelastic model on the material parameters predicted from indentation bending tests of a thin rubber sheet over a low strain range were studied. An inverse program has been developed based on the Kalman filter method to predict the material properties from experimental tests and to assess the uniqueness of the converged results for different material models. The predicted results were compared to standard tests carried out on the same material. Results showed that the Young’s modulus of the material with the linear elastic model can be accurately predicted while the converged parameters (C10 and C01) for the Mooney–Rivlin model were not unique; data analysis showed that parameters C10 and C01 of the converged data were associated with the shear modulus of the material.