Dear all,

I'm interested in the analysis of the contact between two deformable bodies using the ANSYS APDL. However, i couldn't reach correct results for the tangential contact problem exactly the maximum friction stress value and the sliding/ sticking status at the contact surface.

Some experts have recommended to me to check the maximum friction stress TAUMAX value considered in the contact settings. I need to ask you what the formula is exactly should be used to calculate the TAUMAX value that i should input in the contact settings?

According to the ANSYS manual:

'' The program provides one extension of classical Coulomb friction: real constant TAUMAX is maximum contact friction with units of stress. This maximum contact friction stress can be introduced so that, regardless of the magnitude of normal contact pressure, sliding will occur if the friction stress reaches this value. You typically use TAUMAX when the contact pressure becomes very large (such as in bulk metal forming processes). TAUMAX defaults to 1.0e20. Empirical data is often the best source for TAUMAX. Its value may be close to the yield stress of the material being deformed/square(3)''.

in the case of my simulation the yield stress of the steel is 489MPA so i defined TAUMAX as follow: RMODIF,3,9,282.324281633727e6

I need to know if this is the good value, or this should be calculated according to coulomb law? I'm really confused about its value please guid me.

I have another question is Why the maximum friction stress given in the contact results is different than the value of TAUMAX i defined?

Thank you so much,

Best regards