//--------------------------------------------------//
//- rotate fields
{
Info << "Rotating fields" << endl;
volTensorField F = I + gradDU;
U += DU;
epsilon += DEpsilon;
sigma += DSigma;
volTensorField Finv = inv(F);
volScalarField J = det(F);
if(min(J.internalField()) < 0)
FatalErrorIn(args.executable())
<< "Negative Jacobian -> cell negative volumes!!!"
<< exit(FatalError);
}
rho = rho/J;
n = mesh.Sf()/mesh.magSf();
//epsilon = symm(Finv & epsilon & Finv.T());
epsilon = transform(Finv, epsilon);
//sigma = 1/J * symm(F.T() & sigma & F);
sigma = (1/J)*transform(F.T(), sigma);