
Accession Number : AD0694960
Title : FREE VIBRATIONS OF FREEFREE WEBSTIFFENED SANDWICH BEAMS.
Descriptive Note : Research rept.,
Corporate Author : POLYTECHNIC INST OF BROOKLYN N Y DEPT OF AEROSPACE ENGINEERING AND APPLIED MECHANICS
Personal Author(s) : Chen,YoulNan ; Ranlet,David ; Kempner,Joseph
Report Date : SEP 1969
Pagination or Media Count : 63
Abstract : Presented herein is an analysis of the free vibrations of freefree, webstiffened sandwich beams. The mathematical model formulated includes the effect of translatory and rotatory inertia in each layer of the sandwich, and assumes that the faces may be treated as thin layers in which classical beam theory applies. Shear deformations, however, are permitted in the core, which is treated as a layer of orthotropic material comprised of a series of webs considered as discrete elements, except for the inclusion of an average secondary shear modulus induced by the bending of the faces and the webs. Equations are also developed for the free vibrations of the corresponding homogeneously cored sandwich beams, in order to investigate the effect of smearingout or averaging a given webstiffened core. A Galerkintype procedure is employed to determine the natural frequencies from a variational functional generated by means of Hamilton's principle. For freefree, webstiffened sandwich beams of constant weight, the results show that smearingout the webstiffened core introduces significant error into the natural frequencies only when the mass in the core layer is distributed among a small number of webs. (Author)
Descriptors : (*SANDWICH CONSTRUCTION, WEB BEAMS), (*WEB BEAMS, VIBRATION), BEAMS(STRUCTURAL), MATHEMATICAL MODELS, RESONANT FREQUENCY, SHEAR STRESSES, INERTIA, INTERFACES, DEFORMATION, GEOMETRY, FUNCTIONAL ANALYSIS, ERRORS, NUMERICAL METHODS AND PROCEDURES
Subject Categories : Structural Engineering and Building Technology
Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE