Modeling the hardening behavior of rubber-like elastomers under high hydrostatic pressure

Abstract

Elastomers are known to exhibit an increase in elastic modulus under high hydrostatic pressure. To capture this hardening effect, a novel compressible hyperelastic model, extending the framework of Neo-Hookean model, is proposed. This model links volume reduction with microscale properties to describe the pressure-induced increase in effective shear modulus. By measuring the effective shear modulus and fractional volume under varying hydrostatic pressures, the change in elastic modulus for polydimethylsiloxane (PDMS) is quantified. The model is implemented into the commercial finite element software Abaqus via a UHYPER subroutine. Simulations based on the extended Neo-Hookean model accurately reproduce experimental deformations, outperforming the Neo-Hookean model, which showed significant deviations. Specimens with different PDMS mass ratios were tested to investigate the relationship between the hardening factor and microscale properties. The proposed model provides valuable insights for device design and applications in high-pressure environments.