thanks to dj

I think I have found the answers about 2) and 3)

ans to 2):In the harmonic anlysis when we put the displatement boundary in the input page, the software will caculate a 18 points to build a cycle.

ans to 3):Acctually we only could get the maximum data of force and displatement in the result.We cannot get the change about the cycle.

still I do not find the 1) answer.

The vibration comes out from the mechanical vibrate which means that the pipes connect a moving equipment and a static equipment, neither a compressor nor a pump.
We use the pipes to conect a vibration grate which is used in boiler to the header.So the +&-5mm displatement comes from the vibration of the grate.