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lammps/src/USER-SMD/compute_smd_tlsph_stress.cpp
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compute_smd_tlsph_stress.cpp
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/* ----------------------------------------------------------------------
*
* *** Smooth Mach Dynamics ***
*
* This file is part of the USER-SMD package for LAMMPS.
* Copyright (2014) Georg C. Ganzenmueller, georg.ganzenmueller@emi.fhg.de
* Fraunhofer Ernst-Mach Institute for High-Speed Dynamics, EMI,
* Eckerstrasse 4, D-79104 Freiburg i.Br, Germany.
*
* ----------------------------------------------------------------------- */
/* ----------------------------------------------------------------------
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. This software is distributed under
the GNU General Public License.
See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */
#include <string.h>
#include "compute_smd_tlsph_stress.h"
#include "atom.h"
#include "update.h"
#include "modify.h"
#include "comm.h"
#include "force.h"
#include "memory.h"
#include "error.h"
#include "pair.h"
#include <Eigen/Eigen>
using namespace Eigen;
using namespace LAMMPS_NS;
/*
* deviator of a tensor
*/
static Matrix3d Deviator(Matrix3d M) {
Matrix3d eye;
eye.setIdentity();
eye *= M.trace() / 3.0;
return M - eye;
}
/* ---------------------------------------------------------------------- */
ComputeSMDTLSPHStress::ComputeSMDTLSPHStress(LAMMPS *lmp, int narg, char **arg) :
Compute(lmp, narg, arg) {
if (narg != 3)
error->all(FLERR, "Illegal compute smd/tlsph_stress command");
peratom_flag = 1;
size_peratom_cols = 7;
nmax = 0;
stress_array = NULL;
}
/* ---------------------------------------------------------------------- */
ComputeSMDTLSPHStress::~ComputeSMDTLSPHStress() {
memory->sfree(stress_array);
}
/* ---------------------------------------------------------------------- */
void ComputeSMDTLSPHStress::init() {
int count = 0;
for (int i = 0; i < modify->ncompute; i++)
if (strcmp(modify->compute[i]->style, "smd/tlsph_stress") == 0)
count++;
if (count > 1 && comm->me == 0)
error->warning(FLERR, "More than one compute smd/tlsph_stress");
}
/* ---------------------------------------------------------------------- */
void ComputeSMDTLSPHStress::compute_peratom() {
invoked_peratom = update->ntimestep;
Matrix3d stress_deviator;
double von_mises_stress;
// grow vector array if necessary
if (atom->nmax > nmax) {
memory->destroy(stress_array);
nmax = atom->nmax;
memory->create(stress_array, nmax, size_peratom_cols, "stresstensorVector");
array_atom = stress_array;
}
int itmp = 0;
Matrix3d *T = (Matrix3d *) force->pair->extract("smd/tlsph/stressTensor_ptr", itmp);
if (T == NULL) {
error->all(FLERR, "compute smd/tlsph_stress could not access stress tensors. Are the matching pair styles present?");
}
int nlocal = atom->nlocal;
int *mask = atom->mask;
for (int i = 0; i < nlocal; i++) {
if (mask[i] & groupbit) {
stress_deviator = Deviator(T[i]);
von_mises_stress = sqrt(3. / 2.) * stress_deviator.norm();
stress_array[i][0] = T[i](0, 0); // xx
stress_array[i][1] = T[i](1, 1); // yy
stress_array[i][2] = T[i](2, 2); // zz
stress_array[i][3] = T[i](0, 1); // xy
stress_array[i][4] = T[i](0, 2); // xz
stress_array[i][5] = T[i](1, 2); // yz
stress_array[i][6] = von_mises_stress;
} else {
for (int j = 0; j < size_peratom_cols; j++) {
stress_array[i][j] = 0.0;
}
}
}
}
/* ----------------------------------------------------------------------
memory usage of local atom-based array
------------------------------------------------------------------------- */
double ComputeSMDTLSPHStress::memory_usage() {
double bytes = size_peratom_cols * nmax * sizeof(double);
return bytes;
}
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