Multi-Support Excitation Pattern
The Multi-Support pattern allows similar or different prescribed ground motions to be input at various supports in the structure. In OpenSees, the prescribed motion is applied using single-point constraints, the single-point constraints taking their constraint value from user created ground motions.
<uml> abstract class TimeSeries LoadPattern <|-- MultipleSupportExcitation MultipleSupportExcitation o- GroundMotion MultipleSupportExcitation o- ImposedMotionSP ImposedMotionSP --- GroundMotion SP_Constraint <|-- ImposedMotionSP GroundMotion o- TimeSeries </uml>
The command to generate a multi-support excitation contains in { } the commands to generate all the ground motions and the single-point constraints in the pattern. The command is as follows:
| pattern MultipleSupport $patternTag {' |
| groundMotion ... |
| imposedMotion ... |
| ... |
| } |
NOTES:
- The results for the responses at the nodes are the ABSOLUTE values, and not relative values as in the case of a UniformExciatation.
- The non-homogeneous single point constraints require an appropriate choice of constraint handler.
| $patternTag | unique tag among load patterns |
| groundMotion ... | command to generate a ground motion |
| imposedMotion ... | command to generate an imposed motion |
Code Developed by: fmk