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new-materials

hertz_2D.cc
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			/**
			* @file hertz_2D.cc
			*
			* @author Alejandro M. Aragón <alejandro.aragon@epfl.ch>
			*
			* @date creation: Sun Oct 19 2014
			*
			* @brief File used to obtain 2D implicit contact results and compare with
			* Hertz theory
			*
			* @section LICENSE
			*
			* Copyright (©) 2015 EPFL (Ecole Polytechnique Fédérale de Lausanne) Laboratory
			* (LSMS - Laboratoire de Simulation en Mécanique des Solides)
			*
			* Akantu is free software: you can redistribute it and/or modify it under the
			* terms of the GNU Lesser General Public License as published by the Free
			* Software Foundation, either version 3 of the License, or (at your option) any
			* later version.
			*
			* Akantu 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 Lesser General Public License for more
			* details.
			*
			* You should have received a copy of the GNU Lesser General Public License
			* along with Akantu. If not, see <http://www.gnu.org/licenses/>.
			*
			*/

			#include <chrono>

			#include "contact_impl.hh"

			using namespace akantu;

			using std::cout;
			using std::endl;
			using std::setw;
			using std::setprecision;

			int main(int argc, char *argv[]) {
			// set dimension
			static const UInt dim = 2;

			typedef Point <dim> point_type;
			typedef BoundingBox <dim> bbox_type;
			typedef SolidMechanicsModel model_type;
			typedef Contact <dim, MasterAssignator, SelectResolution <_static, _augmented_lagrangian> >
			contact_type;

			typedef std::chrono::high_resolution_clock clock;
			typedef std::chrono::seconds seconds;

			clock::time_point t0 = clock::now();

			initialize("steel.dat", argc, argv);

			// create mesh
			Mesh mesh(dim);

			// read mesh
			mesh.read("hertz_2D.msh");

			// create model
			model_type model(mesh);
			SolidMechanicsModelOptions opt(_static);

			// initialize material
			model.initFull(opt);
			model.updateCurrentPosition();

			// create data structure that holds contact data
			contact_type cd(argc, argv, model);

			// optimal value of penalty multiplier
			cd[Alpha] = 1.e-6;
			cd[Verbose] = true;

			// set Paraview output resluts
			model.setBaseName("contact");
			model.addDumpFieldVector("displacement");

			// use bounding box to minimize slave-master pairs
			Real r0 = 0.5;
			Real r1 = 0.15;
			point_type c1(-r0 / 2, -r1 / 2);
			point_type c2(r0 / 2, r1 / 2);
			bbox_type bb(c1, c2);

			// get physical names from mesh
			Array <Real> &coords = mesh.getNodes();
			mesh.createGroupsFromMeshData <std::string>("physical_names");

			// compute areas for slave nodes that are used for the computation of contact pressures
			model.applyBC(BC::Neumann::FromHigherDim(Matrix <Real>::eye(2, 1.)), "contact_surface");
			// NOTE: the areas are computed by assigning a unit pressure to the contact surface,
			// then the magnitude of the resulting force vector at nodes gives its associated area
			Array <Real>& areas = model.getForce();

			// add slave-master pairs and store slave node areas
			ElementGroup &eg = mesh.getElementGroup("contact_surface");
			for (auto nit = eg.node_begin(); nit != eg.node_end(); ++nit) {
			// get point of slave node
			point_type n(&coords(*nit));

			// process only if within bounding box
			if (bb & n) {
			cd.addSlave(*nit);

			// compute and add area to slave node
			Real a = 0.;
			for (UInt i = 0; i < dim; ++i)
			a += pow(areas(*nit, i), 2.);
			cd.addArea(*nit, sqrt(a));
			}
			}

			// clear force vector before the start of the simulation
			areas.clear();

			// add master surface to find pairs
			cd.searchSurface("rigid");

			// output contact data info
			cout << cd;

			// apply boundary conditions
			model.applyBC(BC::Dirichlet::FixedValue(0., _x), "rigid");
			model.applyBC(BC::Dirichlet::FixedValue(0., _y), "rigid");
			model.getBlockedDOFs()(7, 0) = true;

			Real data[3][50]; // store results for printing
			Real step = 0.001; // top displacement increment
			Real Delta = 0.05; // maximum imposed displacement
			size_t k = 0;

			// loop over displacement increments
			for (Real delta = step; delta <= Delta + step; delta += step) {
			// apply displacement at the top
			model.applyBC(BC::Dirichlet::FixedValue(-delta, _y), "top");

			// solve contact step (no need to call solve on the model object)
			solveContactStep<_generalized_newton>(cd);

			data[0][k] = delta;
			data[1][k] = cd.getForce();
			data[2][k] = cd.getMaxPressure();
			++k;
			}

			// print results
			size_t w = 10;
			cout << setprecision(2);
			cout << "\n\n" << setw(w) << "Disp." << setw(w) << "Force" << setw(w) << "Max pressure" << endl;
			for (int i = 0; i < 50; ++i)
			cout << setw(w) << data[0][i] << setw(w) << data[1][i] << setw(w) << data[2][i] << endl;

			clock::time_point t1 = clock::now();
			seconds total_s = std::chrono::duration_cast <seconds>(t1 - t0);
			cout << "* INFO * Simulation took " << total_s.count() << " s" << endl;

			// finalize simulation
			finalize();
			return EXIT_SUCCESS;
			}

rAKA/examples/contact/hertz_2D.cc891532398ac4features/new-materials

hertz_2D.ccView Options

rAKA/examples/contact/hertz_2D.cc
891532398ac4features/new-materials

hertz_2D.cc
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