Modeling Hardness

[qwicker]

Hi,

I want to model a material (tool steel) during compression testing. Is there a way to put in the hardness number into ansys? I have 2 different variations of the same material with the same Modulus, but different hardness numbers. How would one go about that in ansys? I tried to search but found nothing!

 

[Transient1]

Well, what is the physical meaning of hardness? Why do we measure the hardness of a material?

When your talking about compression testing, what are the goals of the analysis?

 

[qwicker]

We measure hardness to find out how much a material structure can resist surface deformation or impact....

I am modeling a plunger in a press fit machine. I have 2 plungers, one harder than the other. I was asked to model the differences in ansys if possible. The only difference between the materials is the hardness, rockwell.

 

[Transient1]

Okay, I'm not really talking from experience so I may be a bit off. Since your working with various tempers of the same material your saying that the elastic modulus is unchanged. I've heard for steels you can get variation in elastic modulus of around 5% from lot to lot for the same temper.
My previous question about hardness was to get to the fact that Hardness is related to yield strength. At my company we'll measure hardness on a temper grade and that can be related to its yield strength. So one difference is the yield strength and fatigue qualities of the two materials in question. I would assume one part on average will last longer than the other part.
I know you can vary contact stiffness in ANSYS. I would suspect your problem is related to a hertzian contact problem + plastic deformation. It would be a serious analysis and require some accurate material property measurements to simulate.