nodeRotation#

model.nodeRotation(tag)#
Parameters:

  • model (Model) – A Model object

  • tag (int) – The tag of the Node

Returns:

A list of four float components of a normalized quaternion representing the rotation of the node.

This method is used to obtain the current rotation state of a node during an analysis with finite rotations. Rotations are represented with quaternions. Note that by convention, the scalar part of the quaternion is stored at the end of the returned list.

This method can be used with the veux package to visualize 3D cross sectional deformations in frame elements, as demonstrated with this example.

Note

In small deformation analysis, rotations are typically obtained using nodeDisp. However, when finite rotations are involved, these values cannot be used reliably. This is because the values returned by nodeDisp are defined as the algebraic sum of all increments to the solution; this is not valid for finite 3D rotations.

This method is available in sees version 0.1.15.