SBIR-STTR Award

Space habitat inflatable structures require complex material configurations and manufacturing processes. There is a need to develop a standardized accelerated creep test methodology with analysis capability to compute the master creep curves for high strength aramid webbing/cord. Texas Research Institute Austin, Inc. (TRI Austin) in Phase I proposes to refine our in-house developed Step-Isothermal Method (SIM) and Accelerated Life Testing hardware and analysis capability on Kevlar fiber reinforced composites, leveraging the extensive research and development effort of NASA Langley and Ames Research centers. During Phase I we will develop an accelerated creep test methodology to compute baseline master creep curves for selected high strength aramid webbing/cord or other NASA directed structural materials. In Phase II, we will extend the accelerated creep test methodology and analysis capability to compute master creep curves for NASA-specified high strength aramid webbing and/or cord to include larger scale coupon testing. TRI currently offers conventional Creep/Stress Rupture and Stepped Isothermal (SIM) to support the geosynthetic/geotextile industries. TRI Austin is partnering with ILC Dover who is currently developing prototype space habitats for NASA. ILC Dover will supply materials and bring years of experience in selection, optimization, and evaluation of structural materials for current state of the art space habitats to this effort. Potential NASA Applications (Limit 1500 characters, approximately 150 words): The primary NASA application is inflatable softgoods for next generation habitation systems. This research development effort will document creep test methodology and analysis capability to compute master creep curves for NASA specified high strength aramid webbing/cord and generating relevant lifetime material use data. The developed testing methodologies could be included in qualification testing and certification plan for human-rated inflatable space structures, advancing the state-of-the-art in this technology area. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): It is anticipated that with a variety of corporations including Bigelow Aerospace LLC, ILC Dover, Maxar Technologies, Inc., The Boeing Co., Northrop Grumman Corp., and Blue Origin, among others, entering the area of space travel, that demand for evaluating the creep behavior of inflatable structures will increase in coming years as competition for, and quantity of, manned space travel increases. Duration: 6

Space habitat inflatable structures require complex material configurations and manufacturing processes. There is a need to develop a standardized accelerated creep test methodology with analysis capability to compute the master creep curves for high strength Vectran webbing to ensure long-term habitat structural stability. Texas Research Institute Austin, Inc. (TRI Austin) proposes to develop a modified Step-Isothermal Method (SIM) and alternative Accelerated Life Testing methods that can be used for Vectran webbing and yarn based on our Phase I efforts. In Phase II of the program TRI Austin is teaming with Dr. Brown of Clemson’s Center for Advanced Engineering Fibers and Films to characterize the tensile properties of Vectran fibers, as well as using techniques to identify the effect of fiber microstructure, molecular architecture, and intermolecular interactions on Vectran long-term creep behavior. Bally Ribbon Mills will provide expertise in webbing design and manufacturing processes used in its construction and currently manufactures the 24K 2-inch webbing for ILC Dover's prototype space habitat. OTEX, who manufactured the 12.5K 1-inch Vectran used in Phase I, will assist by supplying new webbing and yarn with QA/QC lot testing data. The Phase II program has 14 technical objectives based on our discoveries and theories from the Phase I evaluations that will be addressed in Phase II. In Phase II we can test and address the impact of manufacturing defects, long-term storage, packaging (folding), transportation to space, and final deployment in space with accelerated aging protocols. These test articles will then be assessed with the developed testing protocols to determine mission profile-based reliability performance calculated based on probability and confidence level to estimate field use life. Anticipated

Benefits:
The primary NASA application is inflatable Softgoods for Next Generation Habitation Systems. This research development effort will develop and document creep test methodology and analysis capability to compute master creep curves for Vectran webbing generating relevant lifetime material performance predictions. The developed testing methodologies should be included in Vectran webbing qualification testing and certification plan for human-rated inflatable space structures. It is anticipated that with a variety of corporations including Bigelow Aerospace LLC, ILC Dover, Maxar Technologies, Inc., The Boeing Co., Sierra Nevada Corporation, Northrop Grumman Corp., Lockheed Martin, Blue Origin, and Virgin Galactic, among others, entering the area of space travel, that demand for evaluating the creep behavior of inflatable structures will increase in the coming years.