Dynamic Behavior of Ribbed Viscoelastic CNT-PDMS Thin-Films for Multifunctional Applications

Tailored ribbing structures are obtained by large-scale rolling in polymer PDMS thin-films by adding carbon nanotubes (CNT) inclusions, which significantly improved the mechanical behavior of systems subjected to dynamic compressive strain rates. A nonlinear explicit dynamic three-dimensional finite-element (FE) scheme is used to understand and predict the thermomechanical response of the manufactured ribbed thin-film structures subjected to dynamic in-plane compressive loading. Representative volume element (RVE) FE models of the ribbed thin-films are subjected to strain rates as high as 10⁴ s⁻¹ in both the transverse and parallel ribbing directions. Latin Hypercube Sampling of the microstructural parameters, as informed from experimental observations, provide the microstructurally based RVEs. An interior-point optimization routine is also employed on a regression model trained from the FE predictions that can be used to design ribbed materials for multifunctional applications. The model verifies that damage can be mitigated in CNT-PDMS systems subjected to dynamic compressive loading conditions by controlling the ribbing microstructural characteristics, such as the film thickness and the ribbing amplitude and wavelength. This approach provides a framework for designing materials that can be utilized for applications that require high strain rate damage tolerance, drag reduction, antifouling, and superhydrophobicity.