how to model the base acceleration activation

[hechengli]

if I have a cantilever beam, with one side fixed and the the other side free, and there are acceleration excitation from the fixed side, the whole beam vibration with the base. could some one tell me how to model this in Ansys?

the "fixed side" can't be fixed, coz there is acceleration excitation there. Can I just fixed the other degree of freedom except the UZ degree freedom, and add some equivalent force at the base? any idea ? any suggestion?
Thanks

 

[izax1]

I'm a NASTRAN and not an ANSYS user, but the basic idea for base acceleration is to attach the node(s) to be loaded to a large mass (6-8 orders larger than your FE model) and only restrain the DOF not to be excited. Your natural frequencies should then come up with as many rigid body modes (with close to zero freq) as you have unconstrained DOF. Then you apply the loading to the large mass node(s)
Voila!!!