Modelling stress in cylindrical mesh

[Ahmed-0357]

I currently use FALCON to simulate coupled THM in a cylindrical core with tetrahedral grids, as in the image below. The main challenge I face is modeling a constant normal stress on the curved surface area of the cylinder. The boundary conditions I have tried are outlined below. However, the last two (wall_x, wall_y) are the ones I am having a problem with. Based on the input script snippet below, it appears that FALCON applies the fixed stress magnitude and direction on all the nodes on the curved surface area. This results in the cylinder bending toward the positive x and positive y axes.

Is there a way to make the fixed stress on the curved surface area normal? That way, the stresses on the left of the curved area are balanced by equal and opposite stresses on the right side, etc.

I would greatly appreciate any help or example input files that show how to apply a normal stress on a curved surface in FALCON.

[BCs]

[./bottom_z]

type = DirichletBC

variable = disp_z

value = 0

boundary = 'bottom'

[../]

[./bottom_x]

type = DirichletBC

variable = disp_x

value = 0

boundary = 'bottom'

[../]

[./bottom_y]

type = DirichletBC

variable = disp_y

value = 0

boundary = 'bottom'

[../]

[./top_z]

type = NeumannBC

variable = disp_z

value = 8.6e6

boundary = 'top'

[../]

[./top_x]

type = DirichletBC

variable = disp_x

value = 0

boundary = 'top'

[../]

[./top_y]

type = DirichletBC

variable = disp_y

value = 0

boundary = 'top'

[../]

[./wall_x]

type = NeumannBC

variable = disp_x

value = 8.2e6

boundary = 'wall'

[../]

[./wall_y]

type = NeumannBC

variable = disp_y

value = 8.2e6

boundary = 'wall'

[../]