Mechanical analysis of PDMS films based on different hyperelastic numerical constitutive models

PDMS(polydimethylsiloxane) is widely employed as a substrate material in flexible electronic devices, necessitating its ability to undergo camber deformation while maintaining excellent ductility and flexibility. Understanding the mechanical behavior of PDMS is imperative for its practical applications. Consequently, to numerically investigate the tensile behavior of PDMS, two commonly used hyperelastic constitutive models, the Mooney-Rivlin model and the 3-term Ogden model, have been employed to describe its mechanical characteristics. The material coefficients were determined by fitting the uniaxial tensile experimental data. Subsequently, separate finite element models were developed for the PDMS membrane and the Cu-PDMS composite layer structure. The numerical findings demonstrate that both the Mooney-Rivlin model and the 3-term Ogden model adequately fit the experimental data. Nevertheless, in comparison to the 3-term Ogden model, the PDMS stress distribution exhibits higher values at the same tensile rate, consequently resulting in the fracture of the Cu layer first.