1.2. Element type

Names and IDs

At present, DAMASK incorporates ten different types of element geometries. The table below lists the element types and their equivalent IDs in MSC.Marc and Abaqus. For a detailed information about the characteristics of each element refer to [1] or [2].

Element geometry ID				Dim	Element type	3D view
DAMASK		MSC.Marc	Abaqus
Element	Geometry
1	1	6		2	triangle (plane strain)
2	2	125		2	triangle, second order isoparametric (plane strain)
3	2	11	CPE4	2	arbitrary quadrilateral (plane strain)
4	2	27	CPE8	2	eight-node distorted quadrilateral (plane strain)
5	3	134	C3D4	3	tetrahedron, linear
6	4	127		3	tetrahedron, quadratic
7	4	136	C3D6	3	pentahedral, linear
8	4	117	C3D8R	3	hexahedral, linear (reduced integration)
9	4	7, 57	C3D8, C3D20R	3	hexahedral, linear; hexahedral, quadratic (reduced integration)
10	4	21	C3D20	3	hexahedral, quadratic

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Features

Any element being incorporated has the same geometrical main features. 1 shows these features for the element ID 9. The eight corners represent the nodes having the numbers from 1 to 8. Each of these main nodes have an integration point (not shown in the figure) attached to its site. These are where all the kinematic calculations take place. It is worth to mention that for MSC.Marc the numbers of the integration points (IP) take the same value of their attached nodes with the exception that IP numbers of 3 and 4 are switched with each other as well as numbers 7 and 8. A numbering of the six faces (in this example) is necessary for the calculations. This is being illustrated with red in the figure. An introduction of the so-called subnodes was also essential to fully define all IP volumes. In our example the number of the subnodes are 19 taking the numbers from 9 to 27. In general all other used elements have the same main features of nodes, subnodes, integration points, and faces. They differ in the geometry and the number of components per each feature.

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Application

A local coordinate system is defined with 3 linearly independent directions. It is sorted in (+x), (+y) and (+z) directions related to (1-2), (1-4) and (1-5) directions, respectively.

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References

[1]

MSC.Marc user’s manual, Volume B: Element Library, 2010

[2]

Dassault Systèmes.Abaqus analysis user's manual, Volume IV: Elements, Version 6.10., 2010