The behavior of fabric-film laminates under uniaxial and biaxial loading

Space Structures that require light weight materials with sufficiently high strength and environmental endurance have been in increasing demand since the early 80’s. Not until recently when advances in the textiles and plastics industries made available a wide range of materials that allows the designer to composite structural films with better engineering performance than previously available. The new structures utilize component across the boundaries of several industries. To name a few, homogenous films, co-extruded films, woven fabrics, non-woven fabrics, scrims and nets are just examples. In this study, the mechanical properties of a composite film made of a polyester-based woven fabric laminated to thin homogenous films of polyester (Mylar) and polyethylene (PE) is being measured and analyzed. This fabric/films laminate composite structure is being considered for ’ CopyTight 1999 by the Am&an hwtitutr of Aeronautics and Astronautics, Inc. No copyright is asserted in the United States under Titk 17, U.S. Code. The U.S. Govemnicnt has a royalty-lice liccw to exercise all rights under the copyright claimxJ herein for Governmental F’wposcs. All other rights are reserved by the copyright owner. the development of a material suitable for building large gas envelopes for use in the NASA Ultra Long Duration Balloon Program (ULDB). Compared to commercial homogenous films, the material provides relatively high strength to weight ratio as well as better resistance to crack and tear propagation. The purpose of this paper is to present the uniaxial and biaxial behavior of this class of multi-layers composite and to highlight some of the concerns observed during the characterization of these laminate composites.