Experimental study of thin-walled composite beamsThin-walled rectangular section composite beams are built out of graphite-epoxy prepreg tape using an autoclave molding technique. Cantilevered beams are tested under static loads using a specially-built apparatus and bending slope and elastic twist at a station are measured using a laser system. Measured bending slope and bending-induced twist distributions are correlated with predicted results obtained using a simple beam analysis as well as a refined finite element analysis. Natural vibration characteristics at different rotational speeds are determined experimentally by testing beams in a specially built 10 ft diameter vacuum chamber. The rotor is excited by piezo-electric crystals and response is determined from strain gages mounted on the surface. For composite beams with bending-twisting couplings (symmetric layup), effects of section warping and transverse shear on structural response are found to be substantial. These results were substantiated by the analyses.
Document ID
19890042091
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Chandra, Ramesh (Maryland Univ. College Park, MD, United States)
Ngo, Hieu (Maryland Univ. College Park, MD, United States)
Chopra, Inderjit (Maryland, University College Park, United States)
Date Acquired
August 14, 2013
Publication Date
January 1, 1988
Subject Category
Structural Mechanics
Meeting Information
Meeting: National Technical Specialists'' Meeting on Advanced Rotorcraft Structures