Where to find the cohesion value of metal for the Friction Model of AN 1

[flong208]

Hello,everybody.

Is there someone knows:

Where to find the cohesion value(COHE) of metal for the Friction Model of ANSYS contact analysis?

In ANSYS contact analysis, The Coulomb friction model defines an equivalent shear stress ?, at which sliding on the surface begins as a fraction of the contact pressure p (? = µp + COHE, where µ is the friction coefficient and COHE specifies the cohesion sliding resistance). Once the shear stress is exceeded, the two surfaces will slide relative to each other. This state is known as sliding. The sticking/sliding calculations determine when a point transitions from sticking to sliding or vice versa.

 

[jiligeo]

If you mean cohesion between metal to metal, it is zero. It is probably better to choose a very small value ( e.g.1 kPa).

 

[flong208]

jiligeo,
Thank you, can you tell me where to find more details about the cohesion.

 

[jiligeo]

Hi, in “soil mechanics” text book you can find the method for estimating the values of internal friction and cohesion for soils.
You can find also more information about Mohr- coulomb theory here:

http://en.wikipedia.org/wiki/Mohr-Coulomb_theory

http://www.adhesives.org/TrainingEducation/StudentResources/AdhesionandCohesion.aspx

It is clear that there is no cohesion between two clean metals. If you have something like glue between two metals, then you have also cohesion.