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rAKA/examples/python/phase-field/phasefield-static.py
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phasefield-static.py
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#!/usr/bin/env python
# coding: utf-8
import numpy as np
import py11_akantu as aka
import subprocess
geometry_file = """
element_size = 0.1;
fine_element_size = element_size;
Point(1) = {0.5, 0.5, 0, element_size};
Point(2) = {-0.5, 0.5, 0, element_size};
Point(3) = {-0.5, -0.5, 0, element_size};
Point(4) = {0.5, -0.5, 0, element_size};
Point(5) = {-0.5, 0.001, 0, element_size};
Point(6) = {0., 0.0, 0, fine_element_size};
Point(7) = {0.5, 0.0, 0, fine_element_size};
Point(8) = {-0.5, -0.001, 0, element_size};
Line(1) = {3, 4};
Line(2) = {4, 7};
Line(3) = {7, 1};
Line(4) = {1, 2};
Line(5) = {2, 5};
Line(6) = {5, 6};
Line(7) = {6, 8};
Line(8) = {8, 3};
Line Loop(1) = {1, 2, 3, 4, 5, 6, 7, 8};
Plane Surface(1) = {1};
Physical Surface("plate") = {1};
Physical Line("bottom") = {1};
Physical Line("right") = {2, 3};
Physical Line("top") = {4};
Physical Line("left") = {5,8};
"""
with open('plate.geo', 'w') as f:
f.write(geometry_file)
ret = subprocess.run("gmsh -2 -order 1 -o plate.msh plate.geo", shell=True)
if ret.returncode:
print("Beware, gmsh could not run: mesh is not regenerated")
else:
print("Mesh generated")
material_file = """
material phasefield [
name = plate
rho = 1.
E = 210.0
nu = 0.3
eta = 0.0
Plane_Stress = false
]
phasefield exponential [
name = plate
l0 = 0.0075
gc = 2.7e-3
E = 210.0
nu = 0.3
]
"""
with open('material.dat', 'w') as f:
f.write(material_file)
aka.parseInput("material.dat")
dim = 2
mesh = aka.Mesh(dim)
mesh.read("plate.msh")
model = aka.CouplerSolidPhaseField(mesh)
solid = model.getSolidMechanicsModel()
phase = model.getPhaseFieldModel()
solid.initFull(_analysis_method=aka._static)
solver = solid.getNonLinearSolver('static')
solver.set('max_iterations', 100)
solver.set('threshold', 1e-8)
solver.set("convergence_type", aka.SolveConvergenceCriteria.solution)
solid.getNewSolver("linear_static", aka.TimeStepSolverType.static,
aka.NonLinearSolverType.linear)
solid.setIntegrationScheme("linear_static", "displacement",
aka.IntegrationSchemeType.pseudo_time)
phase.initFull(_analysis_method=aka._static)
phase.getNewSolver("nonlinear_static", aka.TimeStepSolverType.static,
aka.NonLinearSolverType.newton_raphson)
phase.setIntegrationScheme("nonlinear_static", "damage",
aka.IntegrationSchemeType.pseudo_time)
solver = phase.getNonLinearSolver('nonlinear_static')
solver.set('max_iterations', 100)
solver.set('threshold', 1e-4)
solver.set("convergence_type", aka.SolveConvergenceCriteria.solution)
solid.applyBC(aka.FixedValue(0, aka._y), "bottom")
solid.applyBC(aka.FixedValue(0, aka._x), "left")
# Initialization for bulk vizualisation
solid.setBaseName('phasefield-static')
solid.addDumpFieldVector('displacement')
solid.addDumpFieldVector('external_force')
solid.addDumpField('strain')
solid.addDumpField('stress')
solid.addDumpField('damage')
solid.addDumpField('blocked_dofs')
nb_dofs = solid.getMesh().getNbNodes() * dim
increment = solid.getIncrement()
displacement = solid.getDisplacement()
displacement = displacement.reshape(nb_dofs)
blocked_dofs = solid.getBlockedDOFs()
blocked_dofs = blocked_dofs.reshape(nb_dofs)
damage = phase.getDamage()
tolerance = 1e-8
steps = 1500
increment = 1e-5
for n in range(steps):
print("Computing iteration " + str(n + 1) + "/" + str(steps))
solid.applyBC(aka.IncrementValue(increment, aka._y), 'top')
mask = blocked_dofs == False
iiter = 0
error_disp = 1
error_dam = 1
displacement_prev = displacement[mask].copy()
damage_prev = damage.copy()
damage_prev = damage_prev
# solve using staggered scheme
while (error_disp > tolerance or error_dam > tolerance):
model.solve("linear_static", "")
displacement_new = displacement[mask]
damage_new = damage
delta_disp = displacement_new - displacement_prev
delta_dam = damage_new - damage_prev
error_disp = np.linalg.norm(delta_disp)
error_dam = np.linalg.norm(delta_dam)
iiter += 1
displacement_prev = displacement_new.copy()
damage_prev = damage_new.copy()
print(error_dam, error_disp)
if iiter > 500:
raise Exception('Convergence not reached')
if n % 50 == 0:
solid.dump()
solid.dump()
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