Automatically coupling elements of dissimilar dimension in finite element analysis

  • Dermot Monaghan

Student thesis: Doctoral ThesisDoctor of Philosophy


Accuracy and efficiency are two conflicting aspirations in any finite element analysis, and so design analysts are often obliged to use dissimilar elements in a single model. A coupling scheme is required to form a link between the two sides of any mesh transition. In this thesis, details are given on how fully automatic coupling can be achieved for beam to solid transitions, and for beam to shell transitions.

The coupling procedures are implemented via multipoint constraint equations. In order that coupling can be achieved using the outlined methods, the stress distributions at each transition between dissimilar elements must be known. Detailed investigations have been carried out on predictions of linear elastic stress distributions on beam cross-sections due to any given set of loading conditions. These investigations resulted in a comprehensive set of solutions that can evaluate the stress distributions on beams of arbitrary cross-section, with any number of holes on the cross-section.

The overall conclusions were that these coupling approaches provide an excellent way of modelling transitions without the usual problems of increased stiffness and occurrence of spurious stresses at each transition. Sample results for models that have analytical solutions have been obtained, and indicate that the outlined procedures are general and robust. It has also been shown that the algorithms are efficient. All algorithms have been fully automated.
Date of AwardDec 2000
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SupervisorCecil Armstrong (Supervisor)

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