modeling vibration in structures- software

huangyhg

modeling vibration in structures- software?
i am trying to model vibrations induced from mechanical units in structures, and how it affects the structure globally.  i need to locate a fea software that will allow me to input these accelerations into the structure at certain node points or elements...  
anyone know of any software that has this capability??

any fea which offers "dynamic" modelling should be able to do that. however, the models require a force matrix as the excitation. if you only have response (accelerometer) data then you can back-calculate the forces, with the proviso that it is an inherently risky thing to do.
you may have more luck on the fea form.
cheers
greg locock
some time ago, i used staad to model vibrations in structures.  it has been a while, but as i recall one can input the forces as greglocock stated in his response.
the sap2000 by csi is a program that may be useful for fea. i've heard about the good dynamic capabilities of this program.
regards.
juan josé  
staad has the ability to input force or accel vs. time and is good for modeling vibration of multiple equipments at different arrival times.
sap2000 gives more reliable results.