Nonlinear Dynamics by Mode Superposition.

Abstract

A mode superposition technique for approximately solving nonlinear initial-boundary-value problems of structural dynamics is discussed and results, for examples involving large deformation, are compared to those obtained with implicit direct integration methods, such as the Newmark generalized acceleration and Houbolt backward-difference operators. The initial natural frequencies and mode shapes are found through inverse power iteration, with the trial vectors for successively higher modes being swept by Gram-Schmidt orthonormalization at each iteration. The subsequent modal spectrum for nonlinear states is based upon the tangent stiffness of the structure and is calculated by a subspace iteration procedure that involves matrix multiplication only, using the most recently computed spectrum as an initial estimate. The results indicate that a number of important advantages accrue to nonlinear mode superposition. (Modified author abstract)

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1973
Accession Number
AD0769243

Entities

People

  • Robert E. Nickell

Organizations

  • Brown University

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Boundaries
  • Boundary Value Problems
  • Dynamics
  • Frequency
  • Iterations
  • Nonlinear Dynamics
  • Resonant Frequency
  • Spectra
  • Stiffness

Fields of Study

  • Physics

Readers

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