DEVELOPMENT AND EVALUATION OF ENERGY SEARCH METHODS OF NONLINEAR STRUCTURAL ANALYSIS.

Abstract

Mathematical models in the form of potential energy functions are derived for truss, frame and plate discrete elements. Geometric non-linearities are directly incorporated within the discrete element representations to provide for the occurrence of local buckling and to allow detection of general instability. All of the displacement modes employed assure interelement compatibility, as well as intraelement compatibility, which is fundamental to the principle of minimum potential energy. The direct solution of the potential energy formulation is presented as an alternative means of attacking the nonlinear structural analysis problem. The potential energy formulation of a structural system of discrete elements is constructed simply by summing the energy contributions of the individual elements. Mathemaical programming methods of unconstrained minimization are employed in the direct search of the energy function. The goal of the search is to find the stationary point which is equivalent to the solution to the direct formulation. The application of the Reissner energy principle to a structural problem characterized by both geometric and nonconservative material nonlinearities is explored. Specifically an investigation designed to explore special characteristics of this approach is reported. (Author)

Document Details

Document Type
Technical Report
Publication Date
Oct 01, 1965
Accession Number
AD0473367

Entities

People

  • F. K. Bogner
  • L. A. Schmit
  • M. D. Minich
  • R. H. Mallett

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Buckling
  • Computer Programming
  • Detection
  • Displacement
  • Energy
  • Instability
  • Linearity
  • Materials
  • Mathematical Models
  • Models
  • Potential Energy
  • Stationary
  • Structural Analysis

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Structural Dynamics.