Accession Number : ADA258976


Title :   Passive Damping of a Solar Array


Descriptive Note : Master's thesis


Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING


Personal Author(s) : Scharpen, Mark A


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a258976.pdf


Report Date : Dec 1992


Pagination or Media Count : 139


Abstract : This study was an attempt to conceptualize, design, build, and test a constrained layer damping device that uses mechanical advantage for the purpose of increasing the damping of transient vibration of a five-bay planar truss. The aluminum truss was clamped to a fixed support and simulated a solar array. A conventional constrained layer treatment was designed, built, and tested to serve as a benchmark for comparison. For the conventional treatment, Plunkett and Lee's segmented constraining layer technique was used. The improved device, two three-layer sandwich beams spanning the two bays nearest the built-in end, were supported several inches away from the truss plane by a series of levers that were designed to impart a combined shear and bending load to the beam ends. Mindlin and Goodman's method was used to solve a sixth-order, homogeneous differential equation of motion with time-dependent boundary conditions. Experimental results showed that the sandwich beam device did not exceed the loss factors for any of the first four out-of-plane bending modes. However, measurable levels of system damping were achieved for all modes of interest, particularly at the mode whose frequency coincided with that of the sandwich beams.


Descriptors :   *VIBRATION , *SPACECRAFT , *DAMPING , *TRUSSES , *PLANAR STRUCTURES , TEST AND EVALUATION , BEAMS(STRUCTURAL) , MOTION , THESES , BENDING , ALUMINUM , BAYS , SANDWICH CONSTRUCTION , DIFFERENTIAL EQUATIONS , LIGHTWEIGHT , SHEAR STRESSES , STRUCTURAL RESPONSE , STRAIN(MECHANICS) , PASSIVE SYSTEMS , DISPLACEMENT , VISCOELASTICITY , DYNAMICS , FREQUENCY


Subject Categories : Unmanned Spacecraft
      Manned Spacecraft


Distribution Statement : APPROVED FOR PUBLIC RELEASE