BasicQuad#

This command is used to construct a BasicQuad element object which uses the standard Lagrange isoparametric formulation.

model.element("Quad", tag, nodes, section[, pressure, rho, b1, b2])
Parameters:

  • tag – integer, unique element object tag

  • nodes – tuple, a tuple of four element nodes in counter-clockwise order

  • section –

    tuple or int. If int, it is the tag of a previously defined PlaneSection. If tuple, it is a tuple of the form (thick, type, material) where

    thick float

    element thickness

    type |str|

    string representing material behavior. The type parameter can be either 'PlaneStrain' or 'PlaneStress'

    material integer

    tag of an General Materials

  • pressure – float, surface pressure (optional, default = 0.0)

  • rho – float, element mass density (per unit volume) from which a lumped element mass matrix is computed (optional, default=0.0)

  • b1 – float, constant body forces defined in the domain (optional, default=0.0)

  • b2 – float, constant body forces defined in the domain (optional, default=0.0)

The valid eleResponse queries to this element are 'forces', 'stresses', and 'material $matNum matArg1 matArg2 ...' where $matNum refers to the material object at the integration point corresponding to the node numbers in the isoparametric domain.

Consistent nodal loads are computed from the pressure and body forces.

../../../../../_images/Q9.svg

Fig. 27 Quad element node numbering#

Example#

The following example constructs a quad element for use in a plane stress problem with tag 1 between nodes 1, 2, 3, 4 with an nDMaterial of tag 1.

  1. Tcl Code

element quad 1 1 2 3 4 "PlaneStress" 1

  1. Python Code

model.element("quad",1, (1,2,3,4), (1.0, "PlaneStress", 1), (b1, b2, b3))

Code Developed by: Michael H. Scott