Design, Analysis, And Testing Of The PACOSS D-Strut Truss

Report Number: WL-TR-91-3078 Volume III, p. IAB-1 thru IAB-23
Author(s): Morgenthaler, Daniel R.
Corporate Author(s): Martin Marietta Astronautics Group
Date of Publication: 1991-08
Pages: 23
DoD Task:
Identifier: This paper is part of a conference proceedings. See ADA241313

Abstract:
Future space systems may be large, lightweight, and flexible. Such systems will often include trusswork due to the high specific strength and stiffness typical of trusses. Damping of these structures will minimize detrimental vibration, which otherwise may reduce system performance to unacceptable levels. A damping device suitable for application to trusses, which is designated the D-StrutTM,.has been developed by Honeywell. This paper discusses the further development of the damping member, the derivation of analytic procedures required for efficient integration of these members into truss structures, and the results of testing of a structure which incorporates these damping members. Following design, prototyping, fabrication, and impedance testing of D-Strut members, a truss structure which includes these members was assembled and subjected to modal testing. Comparisons of the finite element model of the truss with the experimental modal test data show excellent agreement for the first seven modes, and verify damping levels in the fundamental modes of nearly 10% critical. The D-Struts were compared with viscoelastic extensional damping members designed to produce similar damping levels. These comparisons included weight, temperature stability, strength, etc. Results of the comparisons currently favor the viscoelastic members; however, advances in the design of the viscous device will allow the D-Strut to provide an efficient damping treatment for truss structures of the future.