Vibration of Washing Machines on Wood Framed Floor

[StructTaco]

Hello all,

I am tasked with evaluating a laundromat for changing over to front loading washing machines. The existing top loading machines are supported on a raised floor (wood joists on wood beams on wood posts). The new front loading machines have an inherent problem with vibration since the axis of vibration is rotated and now causes a hammering effect on the flexible support.

So I understand from my old vibrations class that I have to keep the natural frequencies away from each other (the floor vs. the machine)...

Has anyone calc'ed this kind of problem? I can't imagine this is uncommon. Am I right in thinking of solutions being to increase stiffness of the floor, or proposing vibration isolators between the two?

Any help would be appreciated, thanks!!

 

[IRstuff]

Have you done much laundry in a laundomat? I've seen washing machines literally dance around on the floor.

TTFN

FAQ731-376

 

[GregLocock]

If you stiffen the floor and bolt the machines down then you will shake the rest of the building. If you don't bolt the machines down they'll go for a walk as IRStuff says, and still shake. I think you will be very depressed by the results of damping, unless you actually have a resonant condition already.

yes, I have calculated this sort of thing many times. I dare say it is even included as an example in Rao or Thomson.



Cheers

Greg Locock

SIGlease see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Twoballcane]

This more sounds more like a fatigue analysis. The floor will vibrate due to the shock load of the washing machines. So you have to calculate the Fn, deflections and stress and see if continues vibe will break the floor.
IMHO

Tobalcane
"If you avoid failure, you also avoid success."