Configuration Maintenance of Inflated Membrane Structures Using SMA Film Actuators

A methodology to maintain the configuration of inflated membrane structures using shape memory alloy (SMA) film actuator is numerically investigated. The two- dimensional incremental formulation of the SMA constitutive model is developed. New parameters related to the thermodynamic energy equation are introduced to describe more general behaviors of the SMA film. With numerical algorithm of wrinkling and SMAs, the interactions between the inflated membrane structure and the SMA film are investigated by using a finite element program. The effectiveness of SMA film to control the configuration of an inflated membrane structure is examined. To demonstrate surface configuration control, two inflatable membrane structures, each with SMA film are used: (1) an inflatable boom similar to a strut supporting structure and (2) an inflatable reflector, which is comprised of two inflated membranes and torus supporting structures.