The Constraint Method for Solid Finite Elements.

Abstract

In conventional approaches to finite element stress analysis accuracy is obtained by fixing the degree p of the approximating polynomial and by allowing the maximum diameter h of elements in the triangulation of approach zero. An alternate approach is to fix the triangulation and to increase the degree of approximating polynomials in those elements where more accuracy it is necessary to have a family of finite elements of arbitrary polynomial degree p with the property that as much information as possible can be retained from the pth degree approximation when computing the (p/l) st degree approximation. Comparison of the optimal beam (a variable-section beam) with a reference beam (a constant-section beam) shows that the weight reduction depends strongly on the frequency parameter beta. This weight reduction is negligible for beta approaching 0, is 11.3 per cent for beta = 1, is 55.3 per cent for beta = 1.4, and approaches 100 per cent for beta approaching 90 degrees. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 1978
Accession Number
ADA071022

Entities

People

  • I. Norman Katz

Organizations

  • University of Washington

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Accuracy
  • Air Force
  • Algorithms
  • Applied Mathematics
  • Civil Engineering
  • Computer Programs
  • Computers
  • Engineering
  • Mathematics
  • Mechanics
  • Polynomials
  • Rational Functions
  • Stress Analysis
  • Theses
  • Three Dimensional
  • Triangles
  • Two Dimensional

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Geodesy
  • Statistical inference.