parameters.prm

# ----------------------------------------
#            FLEXODEAL (LITE)
# ----------------------------------------
#          Listing of Parameters
# ----------------------------------------

subsection Finite element system
  # Displacement system polynomial order
  set Polynomial degree = 2

  # Gauss quadrature order
  set Quadrature order  = 5

  # Type of simulation (dynamic or quasi-static)
  set Type of simulation = dynamic
end


subsection Geometry
  # Global refinement level
  set Global refinement   = 2

   # Length of the muscle block [m]
  set Length = 0.03

  # Width of the muscle block [m]
  set Width = 0.01

  # Height of the muscle block [m]
  set Height = 0.01

  # Global grid scaling factor (note that this factor
  # scales the grid and nothing else)
  set Grid scale          = 1

  # Ratio of applied pressure to reference pressure 
  # [nondimensional]
  set Pressure ratio p/p0 = 0
end


subsection Linear solver
  # Linear solver iterations (multiples of the system matrix size)
  # In 2-d, this value is best set at 2. In 3-d, a value of 1 work fine.
  set Max iteration multiplier = 2

  # Linear solver residual (scaled by residual norm)
  set Residual                 = 1e-6
  
  # Use static condensation and solve a 1-block system, or solve
  # the full 3-block system using Linear Operators and the Schur
  # complement
  set Use static condensation = false

  # Preconditioner type (jacobi or ssor)
  set Preconditioner type  = jacobi

  # Preconditioner relaxation value
  set Preconditioner relaxation  = 0.65

  # Type of solver used to solve the linear system (GMRES, CG, or Direct).
  # Small problems (Grid refinement level 1 or 2) can usually be solved
  # using the Direct (UMFPACK) solver without issues. However, for larger
  # problems, a CG solver with a Jacobi preconditioner is recommended.
  set Solver type              = Direct
end


subsection Materials
  # Density of muscle [kg/m^3]
  set Muscle density = 1060

  # -------------- Fibre properties -----------------

  # Maximum isometric stress [Pa]
  set Sigma naught muscle = 2.0e5

  # Bulk modulus muscle [Pa]
  set Bulk modulus muscle = 1.0e7

  # Maximum strain rate [1/s]
  set Max strain rate = 5.0

  # Initial fibre orientation (must be a unit vector)
  set Muscle x component = 0.86602540
  set Muscle y component = 0.0
  set Muscle z component = 0.50000000
  
  # ----------- Base material properties ------------

  # Maximum isometric stress base material [Pa]
  # (which is usually equal to that of the muscle fibres)
  set Sigma naught base material = 2.0e5

  # Base material "fudge" factor [nondimensional]. 
  # Ideally this should be 1.
  set Muscle base material factor = 1.0

  # Constants in Yeoh strain-energy function
  set Muscle base material constant 1 = 0.1990559575103343
	set Muscle base material constant 2 = 0.3662334826469149
	set Muscle base material constant 3 = 0.0
end


subsection Nonlinear solver
  # Type of nonlinear solve (classicNewton or acceleratedNewton).
  # Note that classicNewton is STRONGLY suggested as acceleratedNewton
  # hasn't shown good performance at all.
  set Nonlinear solver type = classicNewton

  # Number of Newton-Raphson iterations allowed.
  # Note that dynamic simulations can easily require 10 to 15 
  # times the amount of Newton iterations per time step required 
  # for the quasi-static problem.
  set Max iterations Newton-Raphson = 100

  # Displacement error tolerance [m]
  set Tolerance displacement        = 1.0e-4

  # Force residual tolerance (this is the L2 norm of the RHS block vector)
  set Tolerance force               = 1.0e-4
end


subsection Time
  # End time [s]
  # To obtain data for the very last time step, add 1e-08 to
  # the desired end time
  set End time       = 0.50000001

  # Time step size [s]
  set Time step size = 0.025
end


subsection Prescribed displacement
    # Even if you perform an isometric contraction it is important
    # to set this quantity properly as this is the place where
    # forces are computed for the force_data-3d.csv time series file.
    set Pulling face ID  = 1
end


subsection Measuring locations
    # These locations MUST correspond to vertices on the grid. Otherwise
    # the solver returns the error: "The evaluation point ... was not 
    # found among the vertices of the present grid."

    set Markers list file = markers.dat
end