• Solver Fortran File: ForceToStress.f90
• Solver Name: ForceToStress
• Required Output Variable(s): Stress (user defined)
• Required Input Variable(s): Force
• Optional Output Variable(s): None
• Optional Input Variable(s): None

For a given boundary, this solver computes the nodal normal stress equivalent to a given nodal normal force. This can be used also to infer the flux from the knowledge of a debit (should work also to infer a tangential stress from the knowledge of a tangential force).

In the SIF example below, the normal stress on a boundary is inferred from the 3rd component of the Stokes residual.

Solver 1
  Equation = "Navier-Stokes"
  Stabilization Method = String Stabilized
  Flow Model = Stokes
  ...

  Exported Variable 1 = Flow Solution Loads[Fx:1 Fy:1 Force:1 CEQ Residual:1 ]
  Calculate Loads = Logical True
End

Solver 2
    Equation = "ForceToStress"
    Procedure = File "ElmerIceSolvers" "ForceToStress"
    Variable = String "Stress"
    Variable DOFs = 1

    Linear System Solver = Direct
    Linear System Direct Method = umfpack
 End

! Solve this for body Id 2 (=boundary 3 here)
Equation 2
  Active Solvers(1) = 2
End

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Boundary Condition 3
  Target Boundaries = 5
  Body Id = 2
  ...
End

In this example, a pressure applied on a boundary is first integrated to get nodal force using the GetHydrostaticLoad Solver, and then the pressure is recovered using the ForceToStress Solver.