How to determine Horzontal frequency of a system 1

[eit09]

I have a vibrating screen that is mounted on springs which are supported by a steel structure. I am only interested in the frequency of the screen/spring system. I use the formula
3.13*√(k/w) for the vertical frequency of the screen/spring system. Now I need to calculate the horizontal frequency of the system but do not have a references or guidance to calculate. Please provide some guidance in regards to calculating the horizontal frequency.

 

[GregLocock]

Can you post the complete question including the diagrams?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[btrueblood]

And how many points is it worth.

 

[Twoballcane]

The path to think about is to calculate the inertia of the plate in the bending orientation in question (horizontal in this case), then calculate the deflection, then calculate K, which you can plug back into your resonate frequency equation. Depending on the geometry, this can be very simple if you can find the deflection equations for beams and plates in the back of your structure book (or better yet in Roark) or incredibly complicated if you have to derive the equations yourself.

Tobalcane
"If you avoid failure, you also avoid success."
“Luck is where preparation meets opportunity”

 

[btrueblood]

The lateral (off-axis) stiffness of coil springs is best found by experiment/test; if you want a pre-test prediction, consult a text like "Mechanical Springs", by Wahl. Realize that in that text, he states that the lateral-axis stiffness of a spring can't be predicted by his equations to any better than about +/-30%.

 

[eit09]

GregLocock
I am looking for a formula to calculate the horizontal frequency of a system. I have the formula for the vertical direction which is posted above.

btrueblood

What are you talking about by points??

Twoballcane

Are you saying that the equations are the same for the vertical and horizontal as long as the stiffness of the springs are the same in horz & vert?

 

[GregLocock]

Reread twoballcane's post. You need to establish the lateral stiffness of your suspension. It may even be behaving like a pendulum.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[eit09]

Ok, I have the lateral stiffnes of the springs and it seems to be permisible to use 3.13*√(k/w)to calc both lateral and vertical system freq.

 

[Twoballcane]

The resonate frequency equation is for any direction. It’s the K (in this equation) that will drive your stiffness in the orientation needed. Also where did the 3.13 come from? Are you using f=(1/(2Pi))(k/m)^.5?

Tobalcane
"If you avoid failure, you also avoid success."
“Luck is where preparation meets opportunity”

 

[eit09]

Twoballcane,

thanks for the reply. same equation you posted just reduced.
(1/2pi)*√386.4=3.13