Input velocity time history warning

[ca493]

Hi Silvia,

I am inputting a velocity time history and receiving the following warning message:

WARNING: GroundMotion::getDisp(double time) - integration is required to get the ground displacements from the ground velocities


I am using the default trpezoidal approximation to integrate the velocity so I am curious why this warning message occurs. The simulation still runs and the node is experiencing the correct velocity but I still want to make sure that this error wasnt referring to something major.

Any suggestions?

Thank you!

[fmk]

because it is integrating the vel you provided to get the displacements .. and trpezoidal method is not a good method of integration for ground motions.

[silvia]

at the end of the day there really are only two ways to impose transient-analysis time histories:
1. accelerations via the uniformexcitation
2. displacements via the multiplesupportexcitation