Conversion of Material properties

GPa is a GigaPascal MPa is a MegaPascal

A Pascal = 1 N/m^2

1 PSI = 6894.757 Pascals, or 6.894757 KiloPascals, or 0.006894757 MegaPascals or 0.000006894757 GigaPascals

Great! Thanks Arlin,

Muggs

Please don't be offended by this, but what is your background/education?

Pa, MPa, GPa, and Psi are units that anyone with some rudimentary training in strengths of materials should be aware of. If you don't have much knowledge in this subject area, what do you need to use the information for?

No offense taken.

I was a Modelmaker for about 15 years, then about 4 years ago I started using SolidWorks with my company and started to do a lot of design. We made toys and consumer electronics, so my background as a modelmaker helped me in the design process. Our "schooled" designers could often design something that would not work in the real world, although it "looked good" on the screen. So to make a long story short, because of my background as a modelmaker, most of my designs "worked" right out of the box. And that did me well until I got laid off this past October, so I'm on my own, and for the first time designing things that are made out of materials other than plastic (steel tubing for instance), instead of the more comfortable, injection molded plastics design. Also, to be honest, being a prototyping/model shop, material properties were rarely a concern of ours. We basically knew that everything was going to be make from ABS, HIPS, PP, etc.

So, anyway as to your question, I'll be using this info to get some COSMOSXpress data on things like "will this thing actually hold 400#, or not".

So as you can see, all of my schooling is from the university of "Seat of the Pants". BTW, This NG is a Godsend. I try not to ask questions that I can figure out myself, but I'll admit, sometimes its easier just to ask here.

Thanks again, Muggs

I figured as much. Just a word of caution/advice. FEA analysis does require a good knowledge of strengths of materials (even though FEA salespersons may try to convince you otherwise). Even seasoned FEA experts back up their analysis with (crude) hand calculations just to ensure the FEA is "in the ballpark."

I would highly recommend taking some strength of materials and FEA courses to help your understanding. Things like fatigue, brittleness, stress concentrations, etc. can have a HUGE impact on your design while FEA often does not take such considerations into account.

While I certainly agree that design experience counts a great deal towards good designing, if you are going to use analytical tools like FEA, you need to know what it can AND CANNOT tell you about failure.

efunda

is a good site for engineering information of all types and has units conversion page . HTH,

JJ

If you don't have engineering training, you might want to get some before you trust your FEA results. FEA can be tricky, and COSMOSXpress will force you to make a lot of assumptions that may not make sense. Where possible, rely on formulas from Machinery's Handbook, or Mark's or some other handbook with strength of materials formulas.

At the very least read up on how the solvers deal with the meshed model to find out how to deal with various geometry issues, and what assumptions are implied in the algorithms.

For some reason it has always been much easier for me to remember the inverse of the above. One MPa=145 psi. (Well, 145.0377 and change, but I hardly ever need four digit accuracy.)

Another great site for units of measurement is

This one really comes in handy for obscure old units.

Jerry Steiger Tripod Data Systems

I usually remember 1 psi ~ 7 kPa Not very accurate, but nice for in-head calcs.

I HIGHLY recommend this for unit conversion:

snippage...

Please do NOT use COSMOSXpress for anything other than a seat of the pants feel for the strength of a part. There is no where near enough control or feedback to ensure that a proper FEA model has been created.

FEA is not a trivial undertaking. Good analysts have years of experience and of training. Just as knowing how to use Microsoft Word does not make you a Pulitzer prize winning author, knowing how to use COSMOSXpress does not make you an FEA analyst. I'm not trying to be condescending here, but there is much more to FEA than meets the eye.

Thanks,

Chris