Comparative Study of Computational Material Models

摘要

The present work aims to investigate the framework for predicting the best model for a hyperelastic material like rubber, which is isotropic and incompressible. Different material models like Mooney-Rivlin, Yeoh, Neo-Hookean and Ogden have been considered. Increase in the usage of rubber in different applications from motor tyres to aerospace etc, drags the interest to study its mechanical properties. In general, Uniaxial test, Biaxial test, Simple planar test, Pure shear test and their combinations are useful to study the complete behaviour of the hyperelastic material. But in the present work, only uniaxial tests have been considered to compare with different computational models in ANSYS. However, reducing number of experiments might lead to inaccurate material parameters in strain energy function and it cannot replicate exactly the behaviour in other modes but it will give a reasonable approximation. Material parameters for all models have been determined by curve fitting the stress-stretch relationship curves for respective models. By using these parameters, a rectangular model was simulated in ANSYS. The stress-strain curves obtained for respective models from the simulated data were compared with the Treloar's uniaxial test data [5]. After comparison of various models, the Mooney-Rivlin 3parameter model was found to fit perfectly with the Treloar's uniaxial test data within the range of 0-2.5 strain. Error obtained for the Mooney-3P was 0.037516 followed by 4.5956822 for Yeoh-1 order, 2.1949167 for Yeoh-2 order, 1.0093652 for Yeoh-3 order and 7.0425402 for Neo-Hookean model.