Toward Rigidization of Inflatable Structures

Active rigidization of a simple structure demonstrates how internal resistive heating can be applied to cause permanent physical strengthening of inflatable structures. Rigidizing a real structure brings to light the issues associated with incorporating the rigidizable resincoated tow onto a separate substrate and provides a useful example of the strength gained through effective rigidization. Using the aforementioned temperature-controlled resistive heating approach and curing profile, a cylindrical tube will be stiffened with U-Nyte Set 201B/carbon fiber composite tow. The main objective of this chapter is to investigate the use of this particular rigidization technology on a small scale and simple approach to stiffening inflatable structures. The incorporation of the CFRP material into systems of other materials is considered and additional IR testing of these samples is used to show that changing the boundary conditions affects the thermal gradient near the resin/fiber composite. A miniature “inflatable, rigidizable boom” is constructed in order to demonstrate controlled rigidization through resistive heating. The boom is compared to its pre-hardened state and the change in material properties are quantified through the cantilevered bending stiffness of the boom. Lastly, the cost of rigidization is evaluated per amount of resin-coated fiber tow used.