Corotational Transformation: Difference between revisions

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This command is used to construct the Corotational Coordinate Transformation (CorotCrdTransf) object. Corotational transformation can be used in large displacement-small strain problems. NOTE: Currently the transformation does not deal with element loads and will ignore any that are applied to the element.
This command is used to construct the Corotational Coordinate Transformation (CorotCrdTransf) object. Corotational transformation can be used in large displacement-small strain problems. NOTE: Currently the transformation does not deal with element loads and will ignore any that are applied to the element.



Revision as of 21:18, 3 March 2010




This command is used to construct the Corotational Coordinate Transformation (CorotCrdTransf) object. Corotational transformation can be used in large displacement-small strain problems. NOTE: Currently the transformation does not deal with element loads and will ignore any that are applied to the element.


For a two-dimensional problem:

geomTransf Corotational $transfTag <-jntOffset $dXi $dYi $dXj $dYj>

For a three-dimensional problem:

geomTransf Corotational $transfTag $vecxzX $vecxzY $vecxzZ <-jntOffset $dXi $dYi $dZi $dXj $dYj $dZj>



$transfTag integer tag identifying transformation
$vecxzX $vecxzY $vecxzZ 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.

$dXi $dYi $dZi joint offset values -- absolute 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) (optional)
$dXj $dYj $dZj joint offset values -- absolute 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) (optional)


The element coordinate system is specified as follows:

The x-axis is the axis connecting the two element nodes; the y- and z-axes are then defined using a vector that lies on a plane parallel to the local x-z plane -- vecxz. The local y-axis is defined by taking the cross product of the vecxz vector and the x-axis.. The section is attached to the element such that the y-z coordinate system used to specify the section corresponds to the y-z axes of the element.



EXAMPLE:

  1. Element 1 : tag 1 : vecxZ = zaxis

geomTransf Corotational 1 0 0 -1

  1. Element 2 : tag 2 : vecxZ = y axis

geomTransf Corotational 2 0 1 0


Code Developed by: Remo Magalhaes de Souza

Images Developed by: Silvia Mazzoni