dktp#
Purpose
2-D 9-DOF Discrete Kirchhoff triangle
Description
In a model description matrix, element property rows for dktp elements follow the standard format
[n1 n2 n3 MatID ProID EltID Theta]
giving the node identification numbers ni, material MatID, property ProID. Other optional information is EltID the element identifier, Theta the angle between material x axis and element x axis (currently unused)
The elements support isotropic materials declared with a material entry described in m_elastic. Element property declarations follow the format described in p_shell.
The dktp element uses the et*dktp routines.
There are three vertices nodes for this triangular Kirchhoff plate element and the normal deflection W(x,y) is cubic along each edge.
We start with a 6-node triangular element with a total D.O.F = 21 :
-
five degrees of freedom at corner nodes :
(9.5) - two degrees of freedom θx and θy at mid side nodes.
Then, we impose no transverse shear deformation γxz = 0 and γyz = 0 at selected nodes to reduce the total DOF = 21 − 6*2 = 9 :
-
three degrees of freedom at each of the vertices of the triangle.
(9.6)
The coordinates of the reference element's vertices are
,
and
.
Surfaces are integrated using a 3 point rule ωk = 1 /3 and bk mid side node.
See also