Structural Modeling of Inflated Foam-Rigidized Aerospace Structures

An ideal aerospace structure would be inexpensive, a convenient size and weight for launch, easily deployed, and provide necessary stiffness/performance. This paper examines one type of potentially inexpensive, easily deployed space structure: the inflated foam-rigidized structure. Research aimed at gaining insight into the construction and structural characteristics of foam-rigidized inflated aerospace structures is presented in this paper. Sample foam-rigidized struts were fabricated using a two-part commercially available closed-cell polyurethane foam that was injected in a controlled fashion into a cylindrical Kapton shell. These struts were tested nondestructively to evaluate bending behavior and destructively to examine material characteristics. Testing of the foam-rigidized struts indicates that significant variations of material properties should be expected when injecting polyurethane foam into a single spot and allowing it to expand to fill a structure. An analytical model of the bending behavior of foam-rigidized inflated struts is also presented and compared with experimental bending data.