KOSEN 한인과학기술자네트워크

High Stiffness Passive Damping Concepts Using Materials or Innovative Mechanisms Primary Sponsor: Department of Defense Deadline: 4/11/2001 KEYWORDS TECHNOLOGY AREAS: Materials / Processes OBJECTIVE: Model, develop and demonstrate novel concepts for passive damping in high stiffness structures by utilizing the unique properties of smart materials or innovative mechanisms. DESCRIPTION: A large amount of passive damping is often desirable in order to minimize vibration in various types of structures. Furthermore, it is often advantageous to distribute damping mechanisms throughout the structure rather than at joints or attachment points, especially when it is desired that the structure as a whole remain stiff. In conventional practice, viscoelastic passive damping layers may be affixed to a structural member such that they absorb energy as they are deformed. Such treatments, however, are highly dependent on temperature, and provide only minimal damping for very stiff structures. Damping concepts are desired that can provide large damping, on the order of 20%, while maintaining structural stiffness. Such concepts may make use of magnetostrictive materials, shape memory alloys (SMA) as a constraining layer, SMA ferromagnetic materials, particle damping, or other innovative active materials or mechanisms. PHASE I: The scope of the Phase I effort will be to identify material systems and/or passive mechanisms with qualities that may be exploited for damping, while maintaining structural stiffness. Insensitivity or adaptability to temperature extremes is also desirable. Modeling and material characterization should be completed in this phase. Feasibility should be demonstrated. PHASE II: The scope of the Phase II effort would be to construct a proof of concept demonstration of the technology developed in Phase I and characterize its performance over a range of temperatures and operating conditions. The results should be extrapolated to hypothesized performance in various applications. PHASE III DUAL USE APPLICATIONS: Large precision deployable space structures will require large intrinsic damping while on orbit over an extreme temperature range. The structural members must also remain stiff to provide precision deployment and alignment. REFERENCES: (1) Friend, R. D. and Kinra, V. K. "Particle impact damping," J. Sound and Vibration, 233(1), p. 93-118, 2000.(2) Carman, G.P. and Mitrovic, M., "Nonlinear Constitutive Relations for Magnetostrictive Materials with Application to 1-D Problems," J. Intelligent Material Systems Structures, 6(5), p. 673-683, 1995.(3) van Humbeeck, J. and Liu, Y. "Shape memory alloys as damping materials," Materials Science Forum, 327-328, p. 331-8, 2000. KEYWORDS: Damping, Smart materials, High stiffness structure DoD Notice: Between January 2 and February 28, 2001, you may talk directly with the DoD scientists and engineers who authored the solicitation topics, to ask technical questions about the topics. The Topic Author is listed in the box below. For reasons of competitive fairness, direct communication between proposers and topic authors is not allowed after February 28, 2001, when DoD begins accepting proposals under this solicitation. TPOC: Thomas Hahn PHONE: 703-696-8483 EMAIL: thomas.hahn@afosr.af.mil After February 28, 2001 proposers may still submit written questions about solicitation topics through the SBIR/STTR Interactive Topic Information System (SITIS). If you have general questions about DoD SBIR program, please contact the DoD SBIR Help Desk at (800) 382-4634 or email to SBIRHELP@teltech.com. NOTE: The Solicitations listed on this site are copies from the various SBIR agency solicitations and are not necessarily the latest and most up-to-date. For this reason, you should use the agency link listed below which will take you directly to the appropriate agency server where you can read the official version of this solicitation and download the appropriate forms and rules. The official link for this solicitation is: http://www.acq.osd.mil/sadbu/sbir/sttr01/dod_sttr01.htm. DoD will begin accepting proposals on March 1, 2001. The solicitation closing date is April 11, 2001.