Determination of Material Parameters of PDMS Material Models by MATLAB

Abstract

Generally, material constants and their corresponding stability regions of hyperelastic constitutive models can be obtained by well-known commercial software. Nonetheless, reproduction of engineering stress-strain curves from these software do not accurately represent of the uniaxial testing data of a Polydimethylsiloxane material (PDMS). This research aimed to develop PP algorithm, which are MATLAB codes, used to determinate hyperelastic material constants and their stability regions from uniaxial testing data of PDMS material. Hyperelastic constitutive models composed of Neo-Hookean; 3, 5, and 9 parameters Mooney-Rivlin; 2^nd and 3^rd order Yeoh; and 1^st, 2^nd and 3^rd order Ogden. Moreover, the accuracies of our results were evaluated by the residual sum of squares (RSS) between testing data and hyperelastic models and compared with ones of ANSYS. In Neo-Hookean and Ogden models, the PP algorithm effectively determined material constants from the uniaxial testing data in which their RSS were lower than ones from ANSYS while the strain limit ranges were comparable. However, in Mooney-Rivlin and Yeoh models, the PP algorithm obtained lower RSS but had narrower strain limit ranges than ones from ANSYS. Finally, the Ogden 3^rd order model is the accurate constitutive model for PDMS since it obtained not only low RSS but also no strain range limit.