adhesion.py
74509e1d1987master

adhesion.py
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			#!/usr/bin/env python3
			# @file
			# @section LICENSE
			#
			# Copyright (©) 2016-2020 EPFL (École Polytechnique Fédérale de Lausanne),
			# Laboratory (LSMS - Laboratoire de Simulation en Mécanique des Solides)
			#
			# This program is free software: you can redistribute it and/or modify
			# it under the terms of the GNU Affero General Public License as published
			# by the Free Software Foundation, either version 3 of the License, or
			# (at your option) any later version.
			#
			# This program is distributed in the hope that it will be useful,
			# but WITHOUT ANY WARRANTY; without even the implied warranty of
			# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
			# GNU Affero General Public License for more details.
			#
			# You should have received a copy of the GNU Affero General Public License
			# along with this program. If not, see <https://www.gnu.org/licenses/>.

			import tamaas as tm
			import matplotlib.pyplot as plt
			import numpy as np
			import argparse

			from matplotlib.colors import ListedColormap


			class AdhesionPython(tm.Functional):
			"""
			Functional class that extends a C++ class and implements the virtual
			methods
			"""

			def __init__(self, rho, gamma):
			tm.Functional.__init__(self)
			self.rho = rho
			self.gamma = gamma

			def computeF(self, gap, pressure):
			return -self.gamma * np.sum(np.exp(-gap / self.rho))

			def computeGradF(self, gap, gradient):
			gradient += self.gamma * np.exp(-gap / self.rho) / self.rho


			parser = argparse.ArgumentParser()
			parser.add_argument('--local-functional', dest="py_adh", action="store_true",
			help="use the adhesion functional written in python")

			args = parser.parse_args()

			# Surface size
			n = 1024

			# Surface generator
			sg = tm.SurfaceGeneratorFilter2D([n, n])
			sg.random_seed = 0

			# Spectrum
			sg.spectrum = tm.Isopowerlaw2D()

			# Parameters
			sg.spectrum.q0 = 16
			sg.spectrum.q1 = 16
			sg.spectrum.q2 = 64
			sg.spectrum.hurst = 0.8

			# Generating surface
			surface = sg.buildSurface()
			surface /= n

			plt.imshow(surface)
			plt.title('Rough surface')

			# Creating model
			model = tm.ModelFactory.createModel(tm.model_type_basic_2d, [1., 1.], [n, n])

			# Solver
			solver = tm.PolonskyKeerRey(model, surface, 1e-12,
			tm.PolonskyKeerRey.gap,
			tm.PolonskyKeerRey.gap)
			adhesion_params = {
			"rho": 2e-3,
			"surface_energy": 2e-5
			}

			# Use the python derived from C++ functional class
			if args.py_adh:
			adhesion = AdhesionPython(adhesion_params["rho"],
			adhesion_params["surface_energy"])
			# Use the C++ class
			else:
			adhesion = tm.ExponentialAdhesionFunctional(surface)
			adhesion.setParameters(adhesion_params)

			solver.addFunctionalTerm(adhesion)

			# Solve for target pressure
			g_target = 5e-2
			solver.solve(g_target)

			tractions = model.traction

			plt.figure()
			plt.imshow(tractions)
			plt.colorbar()
			plt.title('Contact tractions')

			plt.figure()
			zones = np.zeros_like(tractions)
			tol = 1e-6
			zones[tractions > tol] = 1
			zones[tractions < -tol] = -1
			plt.imshow(zones, cmap=ListedColormap(['white', 'gray', 'black']))
			plt.colorbar(ticks=[-2/3, 0, 2/3]).set_ticklabels([
			'Adhesion', 'No Contact', 'Contact'
			])

			plt.title('Contact and Adhesion Zones')

			plt.show()

tamaas/examples/adhesion.py74509e1d1987master

adhesion.pyView Options

tamaas/examples/adhesion.py
74509e1d1987master

adhesion.py
View Options