# yade-users team mailing list archive

## [Question #707851]: calculate applied force on corrugated plate.

```New question #707851 on Yade:

Hi
I'm trying to make a sheared granular fault gouge model.

I've almost developed the model setup.

Before I worked, I set up the plain plate (upper plate of boxes) to apply the normal stress to gouge particles so that It's more simple
to calculate the applied force to the plain plate.

Now, I changed the upper plate to a corrugated plate, so I think I need a new approach for calculating normal and shear stresses.
The corrugated plate is composed of several facets.

I guess that the stress is calculated by measuring particles that are in contact with the corrugated plate.
I expect that the function O.foreces.f(id) would calculate contacted stresses.

If my guess is right, the stress should be calculated by following way:
1) sum(the forces applied on facets)/sum(the area of facets)
2) sum(the stress of each facets)
*The forces applied on facets are measured using O.forces.f(facets' id)

In summary, I want to ask three questions.
1) Dose O.forces.f(id) calculate the forces of the contacted particles/facets?
2) If 1) is right, for the plate composed of several facets, the force of the plate is the sum of the forces of each faect?
3) the normal and shear stress on the corrugated plates is obtained from these forces?