# 4.17.3. Corotational Transformation¶

geomTransf('Corotational', transfTag, '-jntOffset', *dI, *dJ)
geomTransf('Corotational', transfTag, *vecxz)

This command is used to construct the Corotational Coordinate Transformation (CorotCrdTransf) object. Corotational transformation can be used in large displacement-small strain problems.

 transfTag (int) integer tag identifying transformation vecxz (list (float)) X, Y, and Z components of vecxz, the vector used to define the local x-z plane of the local-coordinate system. The local y-axis is defined by taking the cross product of the vecxz vector and the x-axis. These components are specified in the global-coordinate system X,Y,Z and define a vector that is in a plane parallel to the x-z plane of the local-coordinate system. These items need to be specified for the three-dimensional problem. dI (list (float)) joint offset values – offsets specified with respect to the global coordinate system for element-end node i (the number of arguments depends on the dimensions of the current model). dJ (list (float)) joint offset values – offsets specified with respect to the global coordinate system for element-end node j (the number of arguments depends on the dimensions of the current model).

Note

Currently the transformation does not deal with element loads and will ignore any that are applied to the element.