THE DETERMINATION OF FREQUENCIES AND MODES OF UNDAMPED STRUCTURES USING FINITEELEMENT STIFFNESS AND CONSISTENT-MASS MATRICES.

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 consistent-mass matrices which are derived from a finite-element representation of the structure, since it has been shown that superior accuracy is achieved compared with conventional lumped-parameter methods with an equal number of idealized elements. The consistent-mass matrix is a symmetric-mass 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)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1965
Accession Number
AD0620082

Entities

People

  • Helen Mccallum
  • Ronald Young

Organizations

  • Massachusetts Institute of Technology

Tags

DTIC Thesaurus Topics

  • Accuracy
  • Computer Programs
  • Computers
  • Frequency
  • Stiffness

Fields of Study

  • Physics

Readers

  • Linear Algebra
  • Structural Dynamics.
  • Systems Analysis and Design