eextrude

Mapdl.eextrude(action='', nelem='', space='', dist='', theta='', tfact='', bckey='', **kwargs)

Extrudes 2-D plane elements into 3-D solids.

APDL Command: EEXTRUDE

Parameters:

action

Specifies one of the following command behaviors:

AUTO - Extrudes plane elements (PLANE182 and PLANE183)

based on the KEYOPT(3) setting. Complementary elements are also extruded. (See Notes for more information.) This behavior is the default.

PLANE - Extrudes elements in the global Z

direction. KEYOPT(3) of the parent elements is ignored.

AXIS - Extrudes elements about the global Y

axis. KEYOPT(3) of the parent elements is ignored.

TANGENT - Similar to Action = AXIS, except that target

elements are extruded in the global Z direction.

nelem

Number of elements to generate in the extruded direction. If you do not specify a number, the program calculates a number automatically based on the average element size and extrusion distance.

space

Spacing ratio. If positive, this value is the nominal ratio of the last division size to the first division size (if > 1.0, sizes increase, if < 1.0, sizes decrease). If negative, |SPACE| is the nominal ratio of the center division size to the end division size. The default value is 1.0 (uniform spacing).

dist

Distance to extrude in the global Z direction for the plane strain case (Action = PLANE). The default is 1.

theta

Ending angle (in degrees) to extrude about the global Y axis for the axisymmetric case (Action = AXIS). The beginning angle is always 0 degrees. The ending angle defaults to 360 degrees.

tfact

Factor for increasing the rigid target size. The size of the extruded rigid target elements is determined automatically based on the size of the contact elements. The default value is 0.2.

bckey

Controls the nodal orientation in the third direction and boundary-condition mapping (Action = AXIS or TIRE only)

• 0All nodes are rotated to a local Cartesian

  coordinate system where X is the radial, Y axial and Z circumferential direction. All loads and displacements are mapped from the 2-D model to the 3-D model in the local coordinate system.

  If applying rotation ROTY in axisymmetric cases with torsion on the 2-D model, this value sets UZ = 0 at all corresponding 3-D nodes. This value is the default

• 1Only nodes with applied loads and/or displacements

  are rotated to a local Cartesian co- ordinate system where X is the radial, Y axial and Z circumferential direction. All loads are mapped to the 3-D model and all applied displacements are reset to zero.

Notes

The EEXTRUDE command extrudes current-technology elements PLANE182 and PLANE183. Complementary elements TARGE169, CONTA171, CONTA172, and REINF263 will also extrude. Extrusion operates automatically on elements in the selected element set.

For automatic PLANE182 and PLANE183 extrusion (Action = AUTO), based on the element behavior of the plane elements, the command performs as follows:

Plane stress; the element is ignored.

Axisymmetric; the element is extruded 360 degrees about the Y-axis. THETA is ignored.

Plane strain (Z strain = 0.0); the element is extruded a unit distance in the global Z direction.

Plane stress with thickness input; the element is extruded in the Z-direction as specified by the thickness input via a real constant.

Generalized plane strain; the element is ignored.

For an axisymmetric extrusion (Action = AUTO with KEYOPT(3) = 1, Action = AXIS, or Action = TANGENT), the command merges any nodes within the specified tolerance (SELTOL,TOLER) of the axis into a single node, then forms degenerate tetrahedrons, pyramids, or wedges. The default tolerance value is 1.0E-6.

When issuing the EEXTRUDE command within the MAP2DTO3D environment using KEYOPT(3) = 3, mapping results do not provide the correct 3-D results state; therefore, KEYOPT(3) = 3 is suggested only as a tool for extruding the mesh itself as a geometric feature.

For an axisymmetric extrusion, SHELL208 and SHELL209 will extrude.

You can control shape-checking options via the SHPP command.

The extrusion behavior of accompanying contact (CONTA171 and CONTA172) is determined by the plane element settings. Rigid target (TARGE169) elements are extruded in the global Z direction unless axisymmetric extrusion (Action = AXIS) is in effect.

The following table shows each 2-D element capable of extrusion and its corresponding post-extrusion 3-D element:

All element properties are also transferred consistently during extrusion. For example, a 2-D element is extruded to a 3-D element, and a mixed u-P 2-D element is extruded to a mixed u-P 3-D element.