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Numbers?
Posted: Tue Mar 23, 2004 2:12 pm
by Caseman33
I am preforming finite element analysis on poles and I need to know the number of the modulus of elasticity in pole vault poles. If there is anyone out there that could help me out that would be great.
Also i would like to know if anyone knows any people i can contact about this infromation
Thanks
Casey
Posted: Tue Mar 23, 2004 4:29 pm
by shortlineskier
Are you running a nonlinear analysis?
Posted: Tue Mar 23, 2004 10:18 pm
by opalkak
1) You could always call a materials lab and ask for the modulus of elasticity of S glass and E glass.
2) Or you could ask the pole manufactures if they know. UCS's number is 1 800 537 7117 between 8am-4pm pacific
3) Or you could find it out by conducting experiments. I think you will have to measure the thickness of the glass and then find some other method of creating a stress vs strain curve inorder to determine the E from the elastic region (extensometer would be useful if you've got access)
Posted: Wed Mar 24, 2004 1:00 am
by jhesch
sounds like there are several people here involved with engineering...if anyone would like, im highly interested in pursuing engineering in either materials or mechanical in college and am looking for info and job descriptions and what an occupation as an engineer is like....if looking to help someone do somethin you enjoy, PM me. thx

Modulus of elasticity for fiberglass
Posted: Wed Mar 24, 2004 6:59 pm
by PVPhD
I used the ABAQUS FEA program back in 1982-84 to dynamically simulate a pole vault. This was the basis for my Ph.D. dissertation. At that time, I had to use hours of processor time on the mainframe computer at the U. of Illinois. My Mac Powerbook probably has the power to do such an analysis today.
Anyway, the modulus of elasticity reported to me by the manufacturer was 38.61 GPa for S glass and 33.79 GPa for E glass with a tensile yield strength of 7.58 GPa for S glass and 5.86 GPa for E glass. I checked this myself by loading an 8 inch section of pole with foil strain gages mounted on it. The experimental value I got for the modulus of elasticity was 33.76 GPa (the pole piece I used came from a used - broken - dark blue skypole made from E glass).
Hope this helps.
Posted: Wed Mar 24, 2004 8:45 pm
by achtungpv
Every single one of you is way too smart.
You're exactly the kind of people I like to hire since everybody knows A students work for C students!

Posted: Wed Mar 24, 2004 11:31 pm
by jhesch
hey pvPhD, any idea if that program you used was the same or similar to one that Bruce Caldwell from ESSX uses? I remember him mentioning a type of software that im pretty sure also had the letters FEA in them.....who makes that software?
Not so simply
Posted: Thu Mar 25, 2004 8:46 am
by Decamouse
Unless you use multi layers of elements and have changing properties of some of the elements - you are just getting an estimate or average for the E of the pole material - you also have a varying Moment of Inertia in the pole - now end constraint conditions and how you dymanically apply the load is a whole other question.

As far as Finite Element Analysis (FEA) there are many companies that produce them - I have used MSC- NASTRAN, Cosmos-M, C-II, and a few other in computer aided engineering - it is also not to difficult to get great looking result that do not reflect reality -

Posted: Thu Mar 25, 2004 9:12 am
by PVPhD
jhesch wrote:hey pvPhD, any idea if that program you used was the same or similar to one that Bruce Caldwell from ESSX uses? I remember him mentioning a type of software that im pretty sure also had the letters FEA in them.....who makes that software?
I doubt if it is the same program - I did mine study 20 years ago!! It wasn't a study of poles, per se, but a study of the vault itself. It was a 2 dimensional computer simulation of the vault using a segmented model of the vaulter with torques at each joint representing the vaulter's muscle actions as the input to the simulation.
If I wanted a better study of pole design considerations, Decamouse is correct - I would have had to use a much more detailed model of the pole.
STUFF IN STUFF OUT
Posted: Thu Mar 25, 2004 9:48 am
by Bruce Caldwell
STUFF IN STUFF OUT
Most of the results of this software are based on what you put in. The more you know about the material, the process, time, temperature, pressure, flow, the patterns and their local the better your model is.
We used the software available to us for strength, stiffness, and elasticity measures of the material we use in relation to the sizes of mandrels and layouts.
A specific knowledge of the manufacturing processes is necessary to provide the best model.
Posted: Thu Mar 25, 2004 8:17 pm
by Caseman33
i was wondering if you had any ideas on what lenght of pole i should use and the wieght and speed of my vaulter subject (since i need to put all this in neutons). Im trying to make it as real as possible.
Posted: Thu Mar 25, 2004 10:57 pm
by shortlineskier
Garbage in, garbage out.