Calculation of force between particle and stl-wall

Submitted by knoe_ph on Thu, 06/06/2013 - 13:56

Hallo everybody,

I'm wondering how the contact force between particle and an stl-wall is calculated?

In the pair_gran doc the particle-particle contact force is explained, does it also apply to particle-wall contact?

If yes, what does the parameter m* stands for?

Kind regards
Philipp

Forums:

ckloss's picture

ckloss | Thu, 06/06/2013 - 17:04

>>In the pair_gran doc the particle-particle contact force is explained, does it also apply to particle-wall contact?
yes

>>If yes, what does the parameter m* stands for?
m* is the effective mass of the contact. For a particle-wall contact (assuming infinite wall mass), it's the mass of the particle

Cheers
Christoph

knoe_ph | Fri, 06/07/2013 - 09:04

OK thank you very much, thats what I assumed.

One more question: What's the main difference between the hertzian and hookeian approach? Where are the advantages/disadvantages?

Kind regards
Philipp

aaigner's picture

aaigner | Fri, 06/07/2013 - 10:14

Hi,
those approaches differ in the calculation of the normal and tangential stiffness coefficients. In case of Hooke (and constant material properties) the coefficient is a constant, in contrast the stiffness calculated by Hertz depends on the particle overlap. Therefore, Hooke is a linear force-displacement model and Hertz is non-linear.

For more details check the pair_gran docu.

Kind regards
Andreas