# Uniform Excitation Pattern

The UniformExcitation pattern allows the user to apply a uniform excitation to a model acting in a certain direction. The command is as follows:

```tcl pattern UniformExcitation $patternTag $dir -accel $tsTag <-vel0 $vel0> <-fact $cFactor> ```

patternTag

unique tag among load patterns

dir

direction in which ground motion acts

1 - corresponds to translation along the global X axis

2 - corresponds to translation along the global Y axis

3 - corresponds to translation along the global Z axis

4 - corresponds to rotation about the global X axis

5 - corresponds to rotation about the global Y axis

6 - corresponds to rotation about the global Z axis

tsTag

tag of the TimeSeries series defining the acceleration history.

vel0

the initial velocity (optional, default=0.0)

cFactor

constant factor (optional, default=1.0)

NOTES:

  1. The responses obtained from the nodes for this type of excitation are RELATIVE values, and not the absolute values obtained from a multi-support case.

Code Developed by: fmk