
Accession Number : AD0620082
Title : THE DETERMINATION OF FREQUENCIES AND MODES OF UNDAMPED STRUCTURES USING FINITEELEMENT STIFFNESS AND CONSISTENTMASS MATRICES.
Descriptive Note : Technical rept.,
Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE AEROELASTIC AND STRUCTURES RESEARCH LAB
Personal Author(s) : Young,Ronald ; McCallum,Helen
Report Date : JUN 1965
Pagination or Media Count : 92
Abstract : An analysis and a computer program which permit determining the natural mode shapes and frequencies for undamped structures are given. The program is designed to operate on stiffness and consistentmass matrices which are derived from a finiteelement representation of the structure, since it has been shown that superior accuracy is achieved compared with conventional lumpedparameter methods with an equal number of idealized elements. The consistentmass matrix is a symmetricmass matrix with nonzero offdiagonal elements; it is this symmetric nondiagonal feature which the present analysis handles conveniently. In particular, the present method represents a convenient and economical synthesis of existing methods, and may be used to calculate the natural mode shapes and frequencies for any system which is described by a set of symmetric mass and stiffness matrices. (Author)
Descriptors : (*STRUCTURES, ELASTIC PROPERTIES), MATRICES(MATHEMATICS), FREQUENCY, COMPUTER PROGRAMMING
Distribution Statement : APPROVED FOR PUBLIC RELEASE