A Continuum Model for Carbon Nanotube-Infused Polyimides

Polyimides are presently being investigated for a wide range of aeronautic, aerospace and industrial applications due to the fact that they have good thermal and chemical resistance yet are flexible. Within the realm of aerospace applications, polyimides can be employed for deployment, positioning, and vibration attenuation of large structures including thin-film membrane mirrors and gossamer antennas. The inclusion of single wall carbon nanotubes raises the conductivity levels to permit electric discharge. Additionally, they augment the electromechanical coupling properties of piezoelectric polyimides to provide them with actuator capabilities. We present a temperature-dependent material model based on elasticity theory which characterizes stiffness through the material as a function of varying concentrations of single wall nanotubes (SWNT). We begin by investigating the temperature affects on the polyimide. We then discuss the effects of SWNT volume concentration on the composite storage modulus. The composite model takes into account the alignment, interphase, and geometry of the SWNTs.