Symbolic software tools in the development of finite elements
โ Scribed by Anders Eriksson; Costin Pacoste
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 300 KB
- Volume
- 72
- Category
- Article
- ISSN
- 0045-7949
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โฆ Synopsis
Symbolic software has been used in a number of projects concerned with the development of ยฎnite element procedures, primarily aiming at complex, i.e. interacting and higher order instabilities, where high accuracy in formulations is required.The symbolic tools improve the eciency and documentation of the developed procedures, in order to facilitate comparisons between dierent element assumptions. Beam formulations for plane and space models were developed, in total displacement and co-rotational contexts, respectively. Symbolic derivation allowed analytical veriยฎcation of equivalence between certain formulations within these two contexts. Treatment of ยฎnite space rotations, based on the rotational vector makes the history-less treatment of rotations easier, which is needed in the evaluation of critical equilibrium subsets in higher-dimensional parameter space. A co-rotational viewpoint, where local element displacements can be obtained from global variables in a systematic manner, allowed dierent element expressions in a common framework. Dierent simple, linear elements have been tested with respect to computational eciency. A ยฎeld consistence approach was used to develop highly accurate beam and plane stress elements. The common element formulations, based on the matrix multiplication B T DB, is often inecient, due to the large number of operations needed in the matrix product. Other formulations, based on an analytical integration and dierentiation of the strain energy, producing explicit expressions for the stiness terms, were considerably more ecient for certain elements.
๐ SIMILAR VOLUMES
The association of object-oriented programming and symbolic computation techniques introduces certain changes in "nite element code organization. The purpose of this approach is to speed up the design of new formulations. Previous papers have described the basic concepts of the method. In this paper