Difference between revisions of "Element Types"
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In <tt>XML</tt> input files, the first [[Area Command#XML Area Block|<tt><Area></tt> block]] must define an element <tt>type</tt> in an attribute and refer to it by number. Subsequent <tt><Area></tt> blocks can omit the <tt>type</tt> attribute unless the element type is changed to have an analysis with mixed elements. When mixed elements are used, they must be compatible elements. In other words, you can mix linear elements (types 1, 2, and 5) with each other or quadratic elements (types 3, 4, 6, and 8) with each other, but cannot mix linear elements with quadratic elements in the same mesh. | In <tt>XML</tt> input files, the first [[Area Command#XML Area Block|<tt><Area></tt> block]] must define an element <tt>type</tt> in an attribute and refer to it by number. Subsequent <tt><Area></tt> blocks can omit the <tt>type</tt> attribute unless the element type is changed to have an analysis with mixed elements. When mixed elements are used, they must be compatible elements. In other words, you can mix linear elements (types 1, 2, and 5) with each other or quadratic elements (types 3, 4, 6, and 8) with each other, but cannot mix linear elements with quadratic elements in the same mesh. | ||
Finally, solid (or quadrilateral) areas can only use solid elements (types 1, 2, 3, 4, and 8) and interface areas can use only | Finally, solid (or quadrilateral) areas can only use solid elements (types 1, 2, 3, 4, and 8) and interface areas can use only [[Interface Elements|inteface elements]] (type 5 and 6). | ||
Revision as of 11:14, 30 August 2013
This page lists the elements that can be used in FEA calculations.
FEA Element Types
The following elements are currently available in NairnFEA:
- 1 or "3 Node Triangle": 3-node constant-strain triangular elements (linear)
- 2 or "4 Node Quadrilateral": 4-node isoparametric rectangular elements (linear)
- 3 or "8 Node Quadrilateral": 8-node isoparametric rectangular elements (quadratic)
- 4 or "6 Node Triangle": 6-node isoparametric triangular elements (quadratic)
- 5 or "4 Node Interface": 4-node imperfect inteface elements (linear)
- 6 or "6 Node Interface": 6-node imperfect inteface elements (quadratic)
- 8 or "9 Node Lagrange": 9-node Langrangian rectangular element (quadratic) (9 point Gaussian quadrature)
Scripted Input Files
XML Input Files
In XML input files, the first <Area> block must define an element type in an attribute and refer to it by number. Subsequent <Area> blocks can omit the type attribute unless the element type is changed to have an analysis with mixed elements. When mixed elements are used, they must be compatible elements. In other words, you can mix linear elements (types 1, 2, and 5) with each other or quadratic elements (types 3, 4, 6, and 8) with each other, but cannot mix linear elements with quadratic elements in the same mesh.
Finally, solid (or quadrilateral) areas can only use solid elements (types 1, 2, 3, 4, and 8) and interface areas can use only inteface elements (type 5 and 6).