3.3.1.3. Drift Recorder

The Drift recorder records the displacement drift between pairs of nodes. Drift is computed as the relative displacement along a specified degree of freedom divided by the distance between the node pair, measured in a perpendicular global direction. This is commonly used for inter-story drift in building models.

recorder Drift <-file $fileName> <-xml $fileName> <-binary $fileName> <-fileCSV $fileName> <-precision $nSD> <-time> <-dT $deltaT> <-rTolDt $rTol> <-closeOnWrite> -iNode $iNode1 $iNode2 ... -jNode $jNode1 $jNode2 ... -dof $dof -perpDirn $dirn

Note

  1. The number of nodes listed after -iNode must equal the number listed after -jNode. Node pairs are matched by position in the two lists.

  2. Only one output destination option may be used: -file, -xml, -binary, or -fileCSV.

  3. The function returns a value:
    SUCCESS: >0 an integer tag that can be used as a handle to remove a recorder with the remove Command command.
    FAILURE: -1 recorder command failed (read the log)

Example

The following example records drift in DOF 1 between node pairs (1, 3) and (2, 4), using the Y direction to compute story height.

  1. Tcl Code

recorder Drift -file drift.out -time -iNode 1 2 -jNode 3 4 -dof 1 -perpDirn 2

  1. Python Code

recorder('Drift', '-file', 'drift.out', '-time', '-iNode', 1, 2, '-jNode', 3, 4, '-dof', 1, '-perpDirn', 2)

Code developed by: Michael H. Scott