Quantification of hyperelastic material parameters for a 3D-Printed thermoplastic elastomer with different infill percentages
Chih-Hsing Liu, Yang Chen, Sy-Yeu Yang
Abstract
The use of thermoplastic elastomers (TPEs) has become increasingly popular over the years due to growing interest in developing soft robots and compliant mechanisms for various applications. Recent developments in 3D printing technology allows users to print TPEs with pre-specified infill percentages. In order to describe the nonlinear stress-strain behavior of 3D-printed TPE structures using a finite element analysis (FEA), the quantification of hyperelastic material parameters for TPEs at different infill percentages is essential. This study is aimed toward identifying the hyperelastic material parameters for 3D printed TPEs at different infill percentages. The commercial TPE filament, Filastic™, made by BotFeeder is used in this study. Tensile tests are performed to obtain the nonlinear stress-strain relationships for 3D-printed TPE specimens with infill percentages ranging from 30 % to 100 % at 10 % increments. The hyperelastic Ogden model is used to fit the nonlinear stress-strain curves. Regression analyses are performed to investigate the relationships between the infill percentage and each material parameter. The identified hyperelastic material parameters are used to perform an FEA for the tensile test simulation. The simulated results agree well with the experimental data.