### Help to apply shear force at boundary

Posted:

**04 Jan 2016, 08:30**Hello,

I am working on modelling a very small rectangular prism of ice. Imagine a block of ice with larger sheets of some other material firmly attached to the top and bottom. If you pull on the top and bottom in opposite directions the result will be a shear force experienced by the ice block.

I need to model a shear force applied to the top and bottom surfaces of my small ice block, as in the picture. I have made the ‘box’ in ElmerGrid and I have most of my .sif file written but I am having trouble with the boundary conditions for the Navier Stokes solver.

In summary, I would like help to apply a tangential force to two surfaces of a ‘box’ and leave the other surfaces free. I have made an attempt at the BC for the free surfaces but I am not sure where to even start with the sheared surface. I am new to Elmer so any help would be very much appreciated.

Thank you for your time,

Liz

I am working on modelling a very small rectangular prism of ice. Imagine a block of ice with larger sheets of some other material firmly attached to the top and bottom. If you pull on the top and bottom in opposite directions the result will be a shear force experienced by the ice block.

I need to model a shear force applied to the top and bottom surfaces of my small ice block, as in the picture. I have made the ‘box’ in ElmerGrid and I have most of my .sif file written but I am having trouble with the boundary conditions for the Navier Stokes solver.

In summary, I would like help to apply a tangential force to two surfaces of a ‘box’ and leave the other surfaces free. I have made an attempt at the BC for the free surfaces but I am not sure where to even start with the sheared surface. I am new to Elmer so any help would be very much appreciated.

Thank you for your time,

Liz

- Code: Select all
`Boundary Condition 1`

Name = "sides"

Target Boundaries(4) = 2 4 5 6

Depth = Real 0.0

Free Surface = Logical True

End

Boundary Condition 2

Name = "sheared surfaces"

Target Boundaries(2) = 1 3

End