LINEAR EQUALITY CONSTRATINTS IN FINITE ELEMENT APPROXIMATION

A new approach to the formulation of finite element approximation problems is presented. The characteristic feature of this approach is that it permits simultaneous satisfaction of the completeness and continuity requirements, making convergence with respect to both increasing orders of polynomial approximation and reduced element sizes possible. When C sub 1 continuity is enforced, the joint requirements of completeness and continuity introduce linear dependencies among the nodal variables. This precludes inversion of the transformation matrix between the polynomial coefficients and nodal variables at the element level. However, because the linear equations that express interelement continuity posses a block-diagonal structure, it is possible to perform most of the required operations at the element level. The linear dependencies among the constraint equations and among the nodal variables can be evaluated by means of a modified version of the simplex method. The computational procedure is outlined.

• Supplemental Notes:
  • The Association of American Railroads and AMCAR Division of ACF Industries, Inc. provided for partial funding of this project.
• Corporate Authors:

  Washington University, St Louis

  St Louis, MO  United States  63130
• Authors:
  • Szabo, B A
  • Kassos, T
• Publication Date: 1973-9

Media Info

• Features: References;
• Pagination: 41 p.

Subject/Index Terms

• TRT Terms: Computer programs; Finite element method; Linear programming; Mathematical models; Structural analysis; Vehicle design
• Old TRIS Terms: Car design
• Subject Areas: Design; Railroads;

Filing Info

• Accession Number: 00099176
• Record Type: Publication
• Source Agency: Department of Transportation
• Report/Paper Numbers: DOT-OS-30108 Tech. Rpt.
• Contract Numbers: DOT-OS-30108
• Files: TRIS, USDOT
• Created Date: Aug 27 1975 12:00AM