Modeling viscosity. Shear strain=Shear rate?
 

Hello,

I'm developing a UDF for introducing the Cross-WLF viscosity model.

In the Cross-WLF model there's the shear rate variable (see the image).

http://s10.postimg.org/8hud6pcmh/shear_rate.jpg

In the UDF I am using the following code for defining the shear rate:

real shear_rate=C_STRAIN_RATE_MAG(cell,thread);

My doubt is:

Is the strain rate the same as the shear rate?

In case of no, how should I obtain the shear_rate value from ANSYS in the UDF?

Somebody needs extra information?

Please, does somebody know if shear strain is the same of shear rate?

And, if not, how do I obtain "shear rate" in a UDF?

Hi jpina, were you able to formulate the UDF then?