FEM/FEA Torque Wrench

herpamad

Hope this is the right place for this?

I have a torque wrench, and need to calculate several parameters.

I need to calculate

- Stress
- Displacement

and

- Force required to reflect the torque rang (2NM - 30NM)

I have ansys (fea) and mathcad (fem) at my disposal to do these calculations, i am just not 100% sure on where to start?

I have done a free-body diagram, and decided that there should be 3.D.O.F, but not sure if there should only be 2?

BUT

My main problem is, how do i model a torque wrench in Ansys? I have the geomotry all sorted (i think) but i dont know how one should constrain, or even what set-up should be used? I was thinking of static structure?

Help and a push in the right direction would be most helpful, and i would be most greatful.

TVP45

There are different kinds of torque wrenches, so one answer doesn't fit all. Let's assume you're doing the inexpensive beam wrench you might buy at Sears for example.
http://www.sears.com/shc/s/p_10153_1...0070921x00003a
You can make a very quick, fairly accurate calculation using simple beam equations by hand. If you want to do a full-blown FEA on this, I'd suggest modelling it in something like Pro-E and running ANSYS. The simplifications you need to make are to fully constrain the drive end (probably 1/2") and apply a simple perpendicular force to the handle somewhere beyond the dial. The critical parameter in your design will be the deflection.

herpamad

Thanks for that, will give it a go.

I am going to use ANSYS, and i think i can model the geometry in workbench so to eliminate pro/e as its a pain.