void elasticitySolver::computeEffectiveStiffness(std::vector<double> stiff)
{
double st[6] = {0., 0., 0., 0., 0., 0.};
double volTot = 0.;
for(std::size_t i = 0; i < elasticFields.size(); ++i) {
double E = elasticFields[i]._e;
double nu = elasticFields[i]._nu;
SolverField<SVector3> Field(pAssembler, LagSpace);
for(groupOfElements::elementContainer::const_iterator it =
elasticFields[i].g->begin();
it != elasticFields[i].g->end(); ++it) {
MElement *e = *it;
double vol = e->getVolume() * e->getVolumeSign();
int nbVertex = e->getNumVertices();
std::vector<SVector3> val(nbVertex);
double valx[256];
double valy[256];
double valz[256];
for(int k = 0; k < nbVertex; k++) {
MVertex *v = e->getVertex(k);
MPoint p(v);
Field.f(&p, 0, 0, 0, val[k]);
valx[k] = val[k](0);
valy[k] = val[k](1);
valz[k] = val[k](2);
}
double gradux[3];
double graduy[3];
double graduz[3];
SPoint3 center = e->barycenterUVW();
double u = center.x(), v = center.y(), w = center.z();
e->interpolateGrad(valx, u, v, w, gradux);
e->interpolateGrad(valy, u, v, w, graduy);
e->interpolateGrad(valz, u, v, w, graduz);
double eps[6] = {gradux[0],
graduy[1],
graduz[2],
0.5 * (gradux[1] + graduy[0]),
0.5 * (gradux[2] + graduz[0]),
0.5 * (graduy[2] + graduz[1])};
double A = E / (1. + nu);
double B = A * (nu / (1. - 2 * nu));
double trace = eps[0] + eps[1] + eps[2];
st[0] += (A * eps[0] + B * trace) * vol;
st[1] += (A * eps[1] + B * trace) * vol;
st[2] += (A * eps[2] + B * trace) * vol;
st[3] += (A * eps[3]) * vol;
st[4] += (A * eps[4]) * vol;
st[5] += (A * eps[5]) * vol;
volTot += vol;
}
}
for(int i = 0; i < 6; i++) stiff[i] = st[i] / volTot;
}
PView *elasticitySolver::buildStressesView(const std::string postFileName)
{
double sti[6] = {0., 0., 0., 0., 0., 0.};
double str[6] = {0., 0., 0., 0., 0., 0.};
double volTot = 0.;
std::cout << "build stresses view" << std::endl;
std::map<int, std::vector<double> > data;
for(std::size_t i = 0; i < elasticFields.size(); ++i) {
double E = elasticFields[i]._e;
double nu = elasticFields[i]._nu;
SolverField<SVector3> Field(pAssembler, LagSpace);
for(groupOfElements::elementContainer::const_iterator it =
elasticFields[i].g->begin();
it != elasticFields[i].g->end(); ++it) {
MElement *e = *it;
double vol = e->getVolume() * e->getVolumeSign();
int nbVertex = e->getNumVertices();
std::vector<SVector3> val(nbVertex);
double valx[256];
double valy[256];
double valz[256];
for(int k = 0; k < nbVertex; k++) {
MVertex *v = e->getVertex(k);
MPoint p(v);
Field.f(&p, 0, 0, 0, val[k]);
valx[k] = val[k](0);
valy[k] = val[k](1);
valz[k] = val[k](2);
}
double gradux[3];
double graduy[3];
double graduz[3];
SPoint3 center = e->barycenterUVW();
double u = center.x(), v = center.y(), w = center.z();
e->interpolateGrad(valx, u, v, w, gradux);
e->interpolateGrad(valy, u, v, w, graduy);
e->interpolateGrad(valz, u, v, w, graduz);
double eps[6] = {gradux[0],
graduy[1],
graduz[2],
0.5 * (gradux[1] + graduy[0]),
0.5 * (gradux[2] + graduz[0]),
0.5 * (graduy[2] + graduz[1])};
double A = E / (1. + nu);
double B = A * (nu / (1. - 2 * nu));
double trace = eps[0] + eps[1] + eps[2];
double sxx = A * eps[0] + B * trace;
double syy = A * eps[1] + B * trace;
double szz = A * eps[2] + B * trace;
double sxy = A * eps[3];
double sxz = A * eps[4];
double syz = A * eps[5];
std::vector<double> vec(9);
vec[0] = sxx;
vec[1] = sxy;
vec[2] = sxz;
vec[3] = sxy;
vec[4] = syy;
vec[5] = syz;
vec[6] = sxz;
vec[7] = syz;
vec[8] = szz;
data[e->getNum()] = vec;
for(int k = 0; k < 6; k++) str[k] += eps[k] * vol;
sti[0] += sxx * vol;
sti[1] += syy * vol;
sti[2] += szz * vol;
sti[3] += sxy * vol;
sti[4] += sxz * vol;
sti[5] += syz * vol;
volTot += vol;
}
}
for(int i = 0; i < 6; i++) {
str[i] = str[i] / volTot;
sti[i] = sti[i] / volTot;
}
printf("effective stiffn = ");
for(int i = 0; i < 6; i++) printf("%g ", sti[i]);
printf("\n");
printf("effective strain = ");
for(int i = 0; i < 6; i++) printf("%g ", str[i]);
printf("\n");
PView *pv = new PView(postFileName, "ElementData", pModel, data, 0.0);
return pv;
}