NASA SBIR 2006 Solicitation
FORM B - PROPOSAL SUMMARY
PROPOSAL NUMBER: |
06-2 A2.01-9428 |
PHASE 1 CONTRACT NUMBER: |
NNX07CA38P |
SUBTOPIC TITLE: |
Materials and Structures for Future Aircraft |
PROPOSAL TITLE: |
Ceramic Composite Mechanical Fastener System for High-Temperature Structural Assemblies |
SMALL BUSINESS CONCERN (Firm Name, Mail Address, City/State/Zip, Phone)
Hyper-Therm High-Temperature Composites
18411 Gothard Street, Units B&C
Huntington Beach, CA 92648 - 1208
(714) 375-4085
PRINCIPAL INVESTIGATOR/PROJECT MANAGER (Name, E-mail, Mail Address, City/State/Zip, Phone)
Wayne Steffier
wsteffier@htcomposites.com
18411 Gothard Street, Units B & C
Huntington Beach, CA 92648 - 1208
(714) 375-4085
TECHNICAL ABSTRACT (Limit 2000 characters, approximately 200 words)
Under Phase I, the feasibility of a novel thermal stress-free ceramic composite mechanical fastener system suitable for assembly of high-temperature composite structures was successfully demonstrated. The innovative 2-dimensional (2D) fastener design facilitates joining load-bearing hot structural assemblies and can be produced at a cost much lower than other competing designs and methods. Functional SiCf/SiCm composite fasteners having two (2) fiber reinforcement orientations of 0/90-degrees (cross-ply) and ±45-degrees (bias-ply) were fabricated for characterization. Testing of the respective fasteners included both axial tension and single-lap shear. The cross-ply reinforced SiCf/SiCm fasteners exhibited axial tensile and single-lap shear strengths of 38.0 and 33.1 ksi, respectively. The bias-ply fasteners exhibited axial tensile and single-lap shear strengths of 31.3 and 29.8 ksi, respectively. Using a generalized analytical method for determining the distribution of forces and stresses in the 2D mechanical fastener developed in Phase I, optimized configurations will be designed and produced in Phase II for evaluation. The metallic subcomponents used for Phase I demonstration will be produced using a high temperature-capable material (e.g., ceramic, superalloy). Aerodynamically smooth Cf/SiCm and SiCf/SiCm composite structural lap joints will be assembled using the optimized composite fastener system for characterization. Testing of the lap joint assemblies will performed to determine the flexibility and structural efficiency of the joint as a function of off-axis loading relative to the principal axis of the fasteners. Elevated temperature testing will be performed to establish the effects of temperature on the mechanical properties of the joint.
POTENTIAL NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
Advanced materials that are capable of surviving sustained extreme environmental conditions, and improved fabrication methods that provide low-cost, robust solutions are needed to achieve specific vehicle platform performance and mission goals. Near-term applications for ceramic composites include expendable chemical rocket thrusters for orbital insertion, on-orbit attitude control system and/or divert thrust chamber components for commercial and military communication spacecraft and/or various ballistic missile defense KE intercept weapons. Applications for ceramic composites in advanced airbreathing and rocket propulsion systems and control surfaces for reusable hypervelocity aerospace vehicles are currently being addressed, however the issues of durability, survivability and maintainability are concerns. Programs are in place for evaluating reinforced ceramics for land-based turbine components, heat exchangers and radiant burners, which represent opportunities in energy and pollution abatement technologies that may mature over the next 10 or so years. Most of these stated applications require joining and attachment to some extent their integration with other components and assemblies.
POTENTIAL NON-NASA COMMERCIAL APPLICATIONS (Limit 1500 characters, approximately 150 words)
Hot structures fabricated from ceramic composite materials are an attractive design option for components of future high-speed aircraft, re-entry vehicles and propulsion systems to reduce weight and increase performance. One important detail in the design of such structures is that of joining and attachment. Large-area hot structures will likely be fabricated by joining smaller component sub-assemblies, since the technology to manufacture complex, co-processed integrated assemblies is immature, and hence of very high risk and cost. Conventional metallic fasteners and fastening techniques do not provide structurally tight joints over a wide temperature range due to the large differences in thermal expansion between the metal fasteners and the mating composite joint members. A metallic fastener, which is snug at room temperature, will loosen at elevated temperature. Excessive assembly preloading at room temperature to maintain a tight joint at elevated temperature may be detrimental to the structural integrity of the joint. Due to the inherent thermo-elastic and elevated temperature strength limitations of metallic fastener materials, ceramic composites on the other hand show real promise to enhance the high temperature performance of mechanically fastened joints in hot composite structures.
NASA's technology taxonomy has been developed by the SBIR-STTR program to disseminate awareness of proposed and awarded R/R&D in the agency. It is a listing of over 100 technologies, sorted into broad categories, of interest to NASA.
TECHNOLOGY TAXONOMY MAPPING |
Ablatives
Aircraft Engines
Airframe
Ceramics
Composites
Launch and Flight Vehicle
Reuseable
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Form Generated on 08-02-07 14:39
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