Improvements of Finite Element Solutions for Structural and Non Structural Applications

Item

Title
Improvements of Finite Element Solutions for Structural and Non Structural Applications
Description
The paper presents a new formulation which allows the derivation of finite element properties in terms of stress functions. It is applicable to both displacement and equilibrium models and leads for certain classes of problems to a substantial reduction in the number of unknowns. The choice of the stress functions as unknowns is identified with an automatic selection procedure of redundancies of minimal diffusion. Therefore this method can be interpreted as a force method in which the numerical search for the redundancies is avoided. It is shown to apply particularly well in certain non structural problems. Independently the effect of the introduction of internal degrees of freedom (bubble functions) in finite elements is evaluated. The conclusion is that a few of such modes can improve significantly the finite element properties and bring them practically in coincidence with assumed stress models.
Creator
Sander, G.
Beckers, P.
Abstract
The paper presents a new formulation which allows the derivation of finite element properties in terms of stress functions. It is applicable to both displacement and equilibrium models and leads for certain classes of problems to a substantial reduction in the number of unknowns. The choice of the stress functions as unknowns is identified with an automatic selection procedure of redundancies of minimal diffusion. Therefore this method can be interpreted as a force method in which the numerical search for the redundancies is avoided. It is shown to apply particularly well in certain non structural problems. Independently the effect of the introduction of internal degrees of freedom (bubble functions) in finite elements is evaluated. The conclusion is that a few of such modes can improve significantly the finite element properties and bring them practically in coincidence with assumed stress models.
Corporate Author
Laboratoire de Techniques Aeronautiques et Spatiales
University of Liege, Belgium
Report Number
AFFDL TR 71-160 p. 305-346
Report Availability
Full text available
Publisher
Wright-Patterson Air Force Base, OH : Air Force Flight Dynamics Laboratory, Air Force Systems Command and Air Force Institute of Technology, Air University
Date
1973
Type
article
Date Issued
1973-12
Provenance
Bombardier/Aero
Distribution Classification
1
Distribution Conflict
No
DTIC Record Exists
No
Format
1 online resource (41 pages) : ill.
Extent
41
Identifier
AD0785968
Is Part Of
Proceedings of the Third Conference on Matrix Methods in Structural Mechanics: Proceedings of the Conference held at Wright-Patterson Air Force Base, Ohio 19-21 October 1971
Media
AFFDLTR71-160article11.pdf

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Items with "Has Part: Improvements of Finite Element Solutions for Structural and Non Structural Applications"
Title Class
Proceedings of the Third Conference on Matrix Methods in Structural Mechanics: Proceedings of the Conference held at Wright-Patterson Air Force Base, Ohio 19-21 October 1971

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