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rGOOSEFEM/src/GooseFEM/DynamicsDiagonal.cpp
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DynamicsDiagonal.cpp
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/* =================================================================================================
(c - GPLv3) T.W.J. de Geus (Tom) | tom@geus.me | www.geus.me | github.com/tdegeus/GooseFEM
================================================================================================= */
#ifndef GOOSEFEM_DYNAMICS_DIAGONAL_CPP
#define GOOSEFEM_DYNAMICS_DIAGONAL_CPP
// -------------------------------------------------------------------------------------------------
#include "DynamicsDiagonal.h"
// ================================= GooseFEM::Dynamics::Diagonal ==================================
namespace GooseFEM {
namespace Dynamics {
namespace Diagonal {
// ===================================== Simulation - Periodic =====================================
template<class Element>
inline Periodic<Element>::Periodic(
std::unique_ptr<Element> _elem, const MatD &_x, const MatS &_conn, const MatS &_dofs, double _dt
)
: elem(std::move(_elem)), conn(_conn), dofs(_dofs), x(_x), dt(_dt)
{
// compute sizes
nnode = static_cast<size_t>(x.rows());
ndim = static_cast<size_t>(x.cols());
nelem = static_cast<size_t>(conn.rows());
nne = static_cast<size_t>(conn.cols());
ndof = dofs.maxCoeff()+1;
// basic checks (mostly the user is 'trusted')
assert( static_cast<size_t>(dofs.size()) == nnode * ndim );
assert( ndof < nnode * ndim );
// allocate and zero-initialize nodal quantities
u.conservativeResize(nnode,ndim); u.setZero();
v.conservativeResize(nnode,ndim); v.setZero();
a.conservativeResize(nnode,ndim); a.setZero();
// allocate and zero-initialize linear system (DOFs)
Minv.conservativeResize(ndof);
M .conservativeResize(ndof);
D .conservativeResize(ndof);
F .conservativeResize(ndof);
V .conservativeResize(ndof);
V_n .conservativeResize(ndof); V_n .setZero();
A .conservativeResize(ndof);
A_n .conservativeResize(ndof); A_n .setZero();
// initialize all fields
updated_x();
updated_u(true);
updated_v(true);
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void Periodic<Element>::velocityVerlet()
{
// (1) new positions (displacements)
// - apply update (nodal) : x_{n+1} = x_n + dt * v_n + .5 * dt^2 * a_n"
u += dt * v + ( .5 * std::pow(dt,2.) ) * a;
// - process update in displacements
updated_u();
// (2a) estimate new velocities
// - update velocities (DOFs)
V.noalias() = V_n + dt * A;
// - convert to nodal velocities (periodicity implies that several nodes depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) v(i) = V(dofs(i));
// - process update in velocities
updated_v();
// - solve for accelerations (DOFs)
A.noalias() = Minv.cwiseProduct( - F - D.cwiseProduct(V) );
// - update velocities (DOFs)
V.noalias() = V_n + ( .5 * dt ) * ( A_n + A );
// - convert to nodal velocities (periodicity implies that several nodes depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) v(i) = V(dofs(i));
// - process update in velocities
updated_v();
// (2b) new velocities
// - solve for accelerations (DOFs)
A.noalias() = Minv.cwiseProduct( - F - D.cwiseProduct(V) );
// - update velocities (DOFs)
V.noalias() = V_n + ( .5 * dt ) * ( A_n + A );
// - convert to nodal velocities (periodicity implies that several nodes depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) v(i) = V(dofs(i));
// - process update in velocities
updated_v();
// (3) new accelerations
// - solve for accelerations (DOFs)
A.noalias() = Minv.cwiseProduct( - F - D.cwiseProduct(V) );
// - convert to nodal acceleration (periodicity implies that several nodes depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) a(i) = A(dofs(i));
// store history
A_n = A; // accelerations (DOFs)
V_n = V; // velocities (DOFs)
t += dt; // current time
// N.B. at this point:
// "a" == "A" == "A_n" -> new nodal accelerations, their DOF equivalents, and a 'back-up'
// "v" == "V_n" -> new nodal velocities, and a 'back-up'
// "u" -> new nodal displacements
// The forces "F" correspond to this state of the system
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void Periodic<Element>::Verlet()
{
// (1) new nodal positions (displacements)
// - apply update (nodal) : x_{n+1} = x_n + dt * v_n + .5 * dt^2 * a_n"
u += dt * v + ( .5 * std::pow(dt,2.) ) * a;
// - process update in displacements
updated_u();
// - solve for accelerations (DOFs)
A.noalias() = Minv.cwiseProduct( - F );
// - convert to nodal acceleration (periodicity implies that several nodes depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) a(i) = A(dofs(i));
// (2) propagate velocities
// - update velocities (DOFs)
V.noalias() = V_n + ( .5 * dt ) * ( A_n + A );
// - convert to nodal velocities (periodicity implies that several nodes depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) v(i) = V(dofs(i));
// store history
A_n = A; // accelerations (DOFs)
V_n = V; // velocities (DOFs)
t += dt; // current time
// N.B. at this point:
// "a" == "A" == "A_n" -> new nodal accelerations, their DOF equivalents, and a 'back-up'
// "v" == "V_n" -> new nodal velocities, and a 'back-up'
// "u" -> new nodal displacements
// The forces "F" correspond to this state of the system
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void Periodic<Element>::ground()
{
// set accelerations and velocities zero (DOFs)
A.setZero();
V.setZero();
// convert to nodal velocity/acceleration (several nodes may depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) a(i) = A(dofs(i));
for ( size_t i=0; i<nnode*ndim; ++i ) v(i) = V(dofs(i));
// store history
A_n = A; // accelerations (DOFs)
V_n = V; // velocities (DOFs)
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void Periodic<Element>::updated_x()
{
// set the nodal positions of all elements (in parallel)
#pragma omp parallel for
for ( size_t e = 0 ; e < nelem ; ++e )
for ( size_t m = 0 ; m < nne ; ++m )
for ( size_t i = 0 ; i < ndim ; ++i )
elem->x(e,m,i) = x(conn(e,m),i);
// signal update
elem->updated_x();
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void Periodic<Element>::updated_u(bool init)
{
// set the nodal displacements of all elements (in parallel)
#pragma omp parallel for
for ( size_t e = 0 ; e < nelem ; ++e )
for ( size_t m = 0 ; m < nne ; ++m )
for ( size_t i = 0 ; i < ndim ; ++i )
elem->u(e,m,i) = u(conn(e,m),i);
// signal update
elem->updated_u();
// update
if ( elem->changed_M or init ) assemble_M();
if ( elem->changed_D or init ) assemble_D();
if ( elem->changed_f or init ) assemble_F();
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void Periodic<Element>::updated_v(bool init)
{
// set the nodal displacements of all elements (in parallel)
#pragma omp parallel for
for ( size_t e = 0 ; e < nelem ; ++e )
for ( size_t m = 0 ; m < nne ; ++m )
for ( size_t i = 0 ; i < ndim ; ++i )
elem->v(e,m,i) = v(conn(e,m),i);
// signal update
elem->updated_v();
// update
if ( elem->changed_M or init ) assemble_M();
if ( elem->changed_D or init ) assemble_D();
if ( elem->changed_f or init ) assemble_F();
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void Periodic<Element>::assemble_M()
{
// zero-initialize
M.setZero();
// temporarily disable parallelization by Eigen
Eigen::setNbThreads(1);
// assemble
#pragma omp parallel
{
// - mass matrix, per thread
ColD M_(ndof);
M_.setZero();
// - assemble diagonal mass matrix, per thread
#pragma omp for
for ( size_t e = 0 ; e < nelem ; ++e )
for ( size_t m = 0 ; m < nne ; ++m )
for ( size_t i = 0 ; i < ndim ; ++i )
M_(dofs(conn(e,m),i)) += elem->M(e,m*ndim+i,m*ndim+i);
// - reduce "M_" per thread to total "M"
#pragma omp critical
M += M_;
}
// automatic parallelization by Eigen
Eigen::setNbThreads(0);
// compute inverse of the mass matrix
Minv = M.cwiseInverse();
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void Periodic<Element>::assemble_D()
{
// zero-initialize
D.setZero();
// temporarily disable parallelization by Eigen
Eigen::setNbThreads(1);
// assemble
#pragma omp parallel
{
// - damping matrix, per thread
ColD D_(ndof);
D_.setZero();
// - assemble diagonal damping matrix, per thread
#pragma omp for
for ( size_t e = 0 ; e < nelem ; ++e )
for ( size_t m = 0 ; m < nne ; ++m )
for ( size_t i = 0 ; i < ndim ; ++i )
D_(dofs(conn(e,m),i)) += elem->D(e,m*ndim+i,m*ndim+i);
// - reduce "D_" per thread to total "D"
#pragma omp critical
D += D_;
}
// automatic parallelization by Eigen
Eigen::setNbThreads(0);
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void Periodic<Element>::assemble_F()
{
// zero-initialize
F.setZero();
// temporarily disable parallelization by Eigen
Eigen::setNbThreads(1);
// assemble
#pragma omp parallel
{
// - force, per thread
ColD F_(ndof);
F_.setZero();
// - assemble force, per thread
#pragma omp for
for ( size_t e = 0 ; e < nelem ; ++e )
for ( size_t m = 0 ; m < nne ; ++m )
for ( size_t i = 0 ; i < ndim ; ++i )
F_(dofs(conn(e,m),i)) += elem->f(e,m,i);
// - reduce "F_" per thread to total "F"
#pragma omp critical
F += F_;
}
// automatic parallelization by Eigen
Eigen::setNbThreads(0);
}
// =================================== Simulation - SemiPeriodic ===================================
template<class Element>
inline SemiPeriodic<Element>::SemiPeriodic(
std::unique_ptr<Element> _elem, const MatD &_x, const MatS &_conn, const MatS &_dofs,
const ColS &_fixedDofs, double _dt
)
: elem(std::move(_elem)), conn(_conn), dofs(_dofs), x(_x), fixedDofs(_fixedDofs), dt(_dt)
{
// compute sizes
nfixed = static_cast<size_t>(fixedDofs.size());
nnode = static_cast<size_t>(x.rows());
ndim = static_cast<size_t>(x.cols());
nelem = static_cast<size_t>(conn.rows());
nne = static_cast<size_t>(conn.cols());
ndof = dofs.maxCoeff()+1;
// basic checks (mostly the user is 'trusted')
assert( static_cast<size_t>(dofs.size()) == nnode * ndim );
assert( ndof < nnode * ndim );
#ifndef NDEBUG
for ( size_t i = 0 ; i < nfixed ; ++i ) assert( fixedDofs(i) < ndof );
#endif
// allocate and zero-initialize nodal quantities
u.conservativeResize(nnode,ndim); u.setZero();
v.conservativeResize(nnode,ndim); v.setZero();
a.conservativeResize(nnode,ndim); a.setZero();
// allocate and zero-initialize linear system (DOFs)
Minv.conservativeResize(ndof);
M .conservativeResize(ndof);
D .conservativeResize(ndof);
F .conservativeResize(ndof);
V .conservativeResize(ndof);
V_n .conservativeResize(ndof); V_n .setZero();
A .conservativeResize(ndof);
A_n .conservativeResize(ndof); A_n .setZero();
// fixed DOFs : default zero velocity and acceleration
fixedV.conservativeResize(nfixed); fixedV.setZero();
fixedA.conservativeResize(nfixed); fixedA.setZero();
// initialize all fields
updated_x();
updated_u(true);
updated_v(true);
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void SemiPeriodic<Element>::velocityVerlet()
{
// (1) new positions (displacements)
// - apply update (nodal) : x_{n+1} = x_n + dt * v_n + .5 * dt^2 * a_n"
u += dt * v + ( .5 * std::pow(dt,2.) ) * a;
// - process update in displacements
updated_u();
// (2a) estimate new velocities
// - update velocities (DOFs)
V.noalias() = V_n + dt * A;
// - apply the fixed velocities
for ( size_t i=0; i<nfixed; ++i ) V(fixedDofs(i)) = fixedV(i);
// - convert to nodal velocities (periodicity implies that several nodes depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) v(i) = V(dofs(i));
// - process update in velocities
updated_v();
// - solve for accelerations (DOFs)
A.noalias() = Minv.cwiseProduct( - F - D.cwiseProduct(V) );
// - update velocities (DOFs)
V.noalias() = V_n + ( .5 * dt ) * ( A_n + A );
// - apply the fixed velocities
for ( size_t i=0; i<nfixed; ++i ) V(fixedDofs(i)) = fixedV(i);
// - convert to nodal velocities (periodicity implies that several nodes depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) v(i) = V(dofs(i));
// - process update in velocities
updated_v();
// (2b) new velocities
// - solve for accelerations (DOFs)
A.noalias() = Minv.cwiseProduct( - F - D.cwiseProduct(V) );
// - update velocities (DOFs)
V.noalias() = V_n + ( .5 * dt ) * ( A_n + A );
// - apply the fixed velocities
for ( size_t i=0; i<nfixed; ++i ) V(fixedDofs(i)) = fixedV(i);
// - convert to nodal velocities (periodicity implies that several nodes depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) v(i) = V(dofs(i));
// - process update in velocities
updated_v();
// (3) new accelerations
// - solve for accelerations (DOFs)
A.noalias() = Minv.cwiseProduct( - F - D.cwiseProduct(V) );
// - apply the fixed accelerations
for ( size_t i=0; i<nfixed; ++i ) A(fixedDofs(i)) = fixedA(i);
// - convert to nodal acceleration (periodicity implies that several nodes depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) a(i) = A(dofs(i));
// store history
A_n = A; // accelerations (DOFs)
V_n = V; // velocities (DOFs)
t += dt; // current time
// N.B. at this point:
// "a" == "A" == "A_n" -> new nodal accelerations, their DOF equivalents, and a 'back-up'
// "v" == "V_n" -> new nodal velocities, and a 'back-up'
// "u" -> new nodal displacements
// The forces "F" correspond to this state of the system
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void SemiPeriodic<Element>::Verlet()
{
// (1) new nodal positions (displacements)
// - apply update (nodal) : x_{n+1} = x_n + dt * v_n + .5 * dt^2 * a_n"
u += dt * v + ( .5 * std::pow(dt,2.) ) * a;
// - process update in displacements
updated_u();
// - solve for accelerations (DOFs)
A.noalias() = Minv.cwiseProduct( - F );
// - apply the fixed accelerations
for ( size_t i=0; i<nfixed; ++i ) A(fixedDofs(i)) = fixedA(i);
// - convert to nodal acceleration (periodicity implies that several nodes depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) a(i) = A(dofs(i));
// (2) propagate velocities
// - update velocities (DOFs)
V.noalias() = V_n + ( .5 * dt ) * ( A_n + A );
// - apply the fixed velocities
for ( size_t i=0; i<nfixed; ++i ) V(fixedDofs(i)) = fixedV(i);
// - convert to nodal velocities (periodicity implies that several nodes depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) v(i) = V(dofs(i));
// store history
A_n = A; // accelerations (DOFs)
V_n = V; // velocities (DOFs)
t += dt; // current time
// N.B. at this point:
// "a" == "A" == "A_n" -> new nodal accelerations, their DOF equivalents, and a 'back-up'
// "v" == "V_n" -> new nodal velocities, and a 'back-up'
// "u" -> new nodal displacements
// The forces "F" correspond to this state of the system
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void SemiPeriodic<Element>::ground()
{
// set accelerations and velocities zero (DOFs)
A.setZero();
V.setZero();
// convert to nodal velocity/acceleration (several nodes may depend on the same DOF)
for ( size_t i=0; i<nnode*ndim; ++i ) a(i) = A(dofs(i));
for ( size_t i=0; i<nnode*ndim; ++i ) v(i) = V(dofs(i));
// store history
A_n = A; // accelerations (DOFs)
V_n = V; // velocities (DOFs)
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void SemiPeriodic<Element>::updated_x()
{
// set the nodal positions of all elements (in parallel)
#pragma omp parallel for
for ( size_t e = 0 ; e < nelem ; ++e )
for ( size_t m = 0 ; m < nne ; ++m )
for ( size_t i = 0 ; i < ndim ; ++i )
elem->x(e,m,i) = x(conn(e,m),i);
// signal update
elem->updated_x();
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void SemiPeriodic<Element>::updated_u(bool init)
{
// set the nodal displacements of all elements (in parallel)
#pragma omp parallel for
for ( size_t e = 0 ; e < nelem ; ++e )
for ( size_t m = 0 ; m < nne ; ++m )
for ( size_t i = 0 ; i < ndim ; ++i )
elem->u(e,m,i) = u(conn(e,m),i);
// signal update
elem->updated_u();
// update
if ( elem->changed_M or init ) assemble_M();
if ( elem->changed_D or init ) assemble_D();
if ( elem->changed_f or init ) assemble_F();
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void SemiPeriodic<Element>::updated_v(bool init)
{
// set the nodal displacements of all elements (in parallel)
#pragma omp parallel for
for ( size_t e = 0 ; e < nelem ; ++e )
for ( size_t m = 0 ; m < nne ; ++m )
for ( size_t i = 0 ; i < ndim ; ++i )
elem->v(e,m,i) = v(conn(e,m),i);
// signal update
elem->updated_v();
// update
if ( elem->changed_M or init ) assemble_M();
if ( elem->changed_D or init ) assemble_D();
if ( elem->changed_f or init ) assemble_F();
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void SemiPeriodic<Element>::assemble_M()
{
// zero-initialize
M.setZero();
// temporarily disable parallelization by Eigen
Eigen::setNbThreads(1);
// assemble
#pragma omp parallel
{
// - mass matrix, per thread
ColD M_(ndof);
M_.setZero();
// - assemble diagonal mass matrix, per thread
#pragma omp for
for ( size_t e = 0 ; e < nelem ; ++e )
for ( size_t m = 0 ; m < nne ; ++m )
for ( size_t i = 0 ; i < ndim ; ++i )
M_(dofs(conn(e,m),i)) += elem->M(e,m*ndim+i,m*ndim+i);
// - reduce "M_" per thread to total "M"
#pragma omp critical
M += M_;
}
// automatic parallelization by Eigen
Eigen::setNbThreads(0);
// compute inverse of the mass matrix
Minv = M.cwiseInverse();
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void SemiPeriodic<Element>::assemble_D()
{
// zero-initialize
D.setZero();
// temporarily disable parallelization by Eigen
Eigen::setNbThreads(1);
// assemble
#pragma omp parallel
{
// - damping matrix, per thread
ColD D_(ndof);
D_.setZero();
// - assemble diagonal damping matrix, per thread
#pragma omp for
for ( size_t e = 0 ; e < nelem ; ++e )
for ( size_t m = 0 ; m < nne ; ++m )
for ( size_t i = 0 ; i < ndim ; ++i )
D_(dofs(conn(e,m),i)) += elem->D(e,m*ndim+i,m*ndim+i);
// - reduce "D_" per thread to total "D"
#pragma omp critical
D += D_;
}
// automatic parallelization by Eigen
Eigen::setNbThreads(0);
}
// -------------------------------------------------------------------------------------------------
template<class Element>
inline void SemiPeriodic<Element>::assemble_F()
{
// zero-initialize
F.setZero();
// temporarily disable parallelization by Eigen
Eigen::setNbThreads(1);
// assemble
#pragma omp parallel
{
// - force, per thread
ColD F_(ndof);
F_.setZero();
// - assemble force, per thread
#pragma omp for
for ( size_t e = 0 ; e < nelem ; ++e )
for ( size_t m = 0 ; m < nne ; ++m )
for ( size_t i = 0 ; i < ndim ; ++i )
F_(dofs(conn(e,m),i)) += elem->f(e,m,i);
// - reduce "F_" per thread to total "F"
#pragma omp critical
F += F_;
}
// automatic parallelization by Eigen
Eigen::setNbThreads(0);
}
// ======================================== Element - Quad4 ========================================
namespace SmallStrain {
// -------------------------------------------------------------------------------------------------
template<class Material>
inline Quad4<Material>::Quad4(std::unique_ptr<Material> _mat, size_t _nelem)
{
// copy from input
nelem = _nelem;
mat = std::move(_mat);
// allocate matrices
// -
x .resize({nelem,nne,ndim});
u .resize({nelem,nne,ndim});
v .resize({nelem,nne,ndim});
f .resize({nelem,nne,ndim});
// -
M .resize({nelem,nne*ndim,nne*ndim});
D .resize({nelem,nne*ndim,nne*ndim});
// -
dNx .resize({nelem,nip,nne,ndim});
// -
vol .resize({nelem,nip});
vol_n .resize({nelem,nne});
// -
dNxi .resize({nip,nne,ndim});
dNxi_n.resize({nne,nne,ndim});
// -
w .resize({nip});
w_n .resize({nne});
// zero initialize matrices (only diagonal is written, no new zero-initialization necessary)
M.setZero();
D.setZero();
// shape function gradient at all Gauss points, in local coordinates
// - k == 0
dNxi(0,0,0) = -.25*(1.+1./std::sqrt(3.)); dNxi(0,0,1) = -.25*(1.+1./std::sqrt(3.));
dNxi(0,1,0) = +.25*(1.+1./std::sqrt(3.)); dNxi(0,1,1) = -.25*(1.-1./std::sqrt(3.));
dNxi(0,2,0) = +.25*(1.-1./std::sqrt(3.)); dNxi(0,2,1) = +.25*(1.-1./std::sqrt(3.));
dNxi(0,3,0) = -.25*(1.-1./std::sqrt(3.)); dNxi(0,3,1) = +.25*(1.+1./std::sqrt(3.));
// - k == 1
dNxi(1,0,0) = -.25*(1.+1./std::sqrt(3.)); dNxi(1,0,1) = -.25*(1.-1./std::sqrt(3.));
dNxi(1,1,0) = +.25*(1.+1./std::sqrt(3.)); dNxi(1,1,1) = -.25*(1.+1./std::sqrt(3.));
dNxi(1,2,0) = +.25*(1.-1./std::sqrt(3.)); dNxi(1,2,1) = +.25*(1.+1./std::sqrt(3.));
dNxi(1,3,0) = -.25*(1.-1./std::sqrt(3.)); dNxi(1,3,1) = +.25*(1.-1./std::sqrt(3.));
// - k == 2
dNxi(2,0,0) = -.25*(1.-1./std::sqrt(3.)); dNxi(2,0,1) = -.25*(1.-1./std::sqrt(3.));
dNxi(2,1,0) = +.25*(1.-1./std::sqrt(3.)); dNxi(2,1,1) = -.25*(1.+1./std::sqrt(3.));
dNxi(2,2,0) = +.25*(1.+1./std::sqrt(3.)); dNxi(2,2,1) = +.25*(1.+1./std::sqrt(3.));
dNxi(2,3,0) = -.25*(1.+1./std::sqrt(3.)); dNxi(2,3,1) = +.25*(1.-1./std::sqrt(3.));
// - k == 3
dNxi(3,0,0) = -.25*(1.-1./std::sqrt(3.)); dNxi(3,0,1) = -.25*(1.+1./std::sqrt(3.));
dNxi(3,1,0) = +.25*(1.-1./std::sqrt(3.)); dNxi(3,1,1) = -.25*(1.-1./std::sqrt(3.));
dNxi(3,2,0) = +.25*(1.+1./std::sqrt(3.)); dNxi(3,2,1) = +.25*(1.-1./std::sqrt(3.));
dNxi(3,3,0) = -.25*(1.+1./std::sqrt(3.)); dNxi(3,3,1) = +.25*(1.+1./std::sqrt(3.));
// integration point weight at all Gauss points
w(0) = 1.;
w(1) = 1.;
w(2) = 1.;
w(3) = 1.;
// shape function gradient at all nodes, in local coordinates
// - k == 0
dNxi_n(0,0,0) = -0.5; dNxi_n(0,0,1) = -0.5;
dNxi_n(0,1,0) = +0.5; dNxi_n(0,1,1) = 0.0;
dNxi_n(0,2,0) = 0.0; dNxi_n(0,2,1) = 0.0;
dNxi_n(0,3,0) = 0.0; dNxi_n(0,3,1) = +0.5;
// - k == 1
dNxi_n(1,0,0) = -0.5; dNxi_n(1,0,1) = 0.0;
dNxi_n(1,1,0) = +0.5; dNxi_n(1,1,1) = -0.5;
dNxi_n(1,2,0) = 0.0; dNxi_n(1,2,1) = +0.5;
dNxi_n(1,3,0) = 0.0; dNxi_n(1,3,1) = 0.0;
// - k == 2
dNxi_n(2,0,0) = 0.0; dNxi_n(2,0,1) = 0.0;
dNxi_n(2,1,0) = 0.0; dNxi_n(2,1,1) = -0.5;
dNxi_n(2,2,0) = +0.5; dNxi_n(2,2,1) = +0.5;
dNxi_n(2,3,0) = -0.5; dNxi_n(2,3,1) = 0.0;
// - k == 3
dNxi_n(3,0,0) = 0.0; dNxi_n(3,0,1) = -0.5;
dNxi_n(3,1,0) = 0.0; dNxi_n(3,1,1) = 0.0;
dNxi_n(3,2,0) = +0.5; dNxi_n(3,2,1) = 0.0;
dNxi_n(3,3,0) = -0.5; dNxi_n(3,3,1) = +0.5;
// integration point weight at all nodes
w_n(0) = 1.;
w_n(1) = 1.;
w_n(2) = 1.;
w_n(3) = 1.;
// Note, the above is a specialization of the following:
//
// - Shape function gradients
//
// dNxi(0,0) = -.25*(1.-xi(k,1)); dNxi(0,1) = -.25*(1.-xi(k,0));
// dNxi(1,0) = +.25*(1.-xi(k,1)); dNxi(1,1) = -.25*(1.+xi(k,0));
// dNxi(2,0) = +.25*(1.+xi(k,1)); dNxi(2,1) = +.25*(1.+xi(k,0));
// dNxi(3,0) = -.25*(1.+xi(k,1)); dNxi(3,1) = +.25*(1.-xi(k,0));
//
// - Gauss point coordinates and weights
//
// xi(0,0) = -1./std::sqrt(3.); xi(0,1) = -1./std::sqrt(3.); w(0) = 1.;
// xi(1,0) = +1./std::sqrt(3.); xi(1,1) = -1./std::sqrt(3.); w(1) = 1.;
// xi(2,0) = +1./std::sqrt(3.); xi(2,1) = +1./std::sqrt(3.); w(2) = 1.;
// xi(3,0) = -1./std::sqrt(3.); xi(3,1) = +1./std::sqrt(3.); w(3) = 1.;
//
// - Nodal coordinates and weights
//
// xi(0,0) = -1.; xi(0,1) = -1.; w(0) = 1.;
// xi(1,0) = +1.; xi(1,1) = -1.; w(1) = 1.;
// xi(2,0) = +1.; xi(2,1) = +1.; w(2) = 1.;
// xi(3,0) = -1.; xi(3,1) = +1.; w(3) = 1.;
}
// =================================================================================================
template<class Material>
inline void Quad4<Material>::updated_x()
{
#pragma omp parallel
{
// intermediate quantities
cppmat::cartesian2d::tensor2<double> J_, Jinv_;
double Jdet_;
// local views of the global arrays (speeds up indexing, and increases readability)
cppmat::tiny::matrix2<double,8,8> M_, D_;
cppmat::tiny::matrix2<double,4,2> dNxi_, dNx_, x_;
cppmat::tiny::vector <double,4> w_, vol_;
// loop over all elements (in parallel)
#pragma omp for
for ( size_t e = 0 ; e < nelem ; ++e )
{
// pointer to element positions
x_.map(&x(e));
// nodal quadrature
// ----------------
// pointer to element mass/damping matrix, nodal volume, and integration weight
M_ .map(&M (e));
D_ .map(&D (e));
vol_.map(&vol_n(e));
w_ .map(&w_n (0));
// loop over nodes, i.e. the integration points
for ( size_t k = 0 ; k < nne ; ++k )
{
// - pointer to the shape function gradients (local coordinates)
dNxi_.map(&dNxi_n(k));
// - Jacobian
// J(i,j) += dNxi(m,i) * xe(m,j)
J_(0,0) = dNxi_(0,0)*x_(0,0) + dNxi_(1,0)*x_(1,0) + dNxi_(2,0)*x_(2,0) + dNxi_(3,0)*x_(3,0);
J_(0,1) = dNxi_(0,0)*x_(0,1) + dNxi_(1,0)*x_(1,1) + dNxi_(2,0)*x_(2,1) + dNxi_(3,0)*x_(3,1);
J_(1,0) = dNxi_(0,1)*x_(0,0) + dNxi_(1,1)*x_(1,0) + dNxi_(2,1)*x_(2,0) + dNxi_(3,1)*x_(3,0);
J_(1,1) = dNxi_(0,1)*x_(0,1) + dNxi_(1,1)*x_(1,1) + dNxi_(2,1)*x_(2,1) + dNxi_(3,1)*x_(3,1);
// - determinant of the Jacobian
Jdet_ = J_.det();
// - integration point volume
vol_(k) = w_(k) * Jdet_;
// - assemble element mass matrix
// M(m+i,n+i) += N(m) * rho * vol * N(n);
M_(k*2 ,k*2 ) = mat->rho(e,k) * vol_(k);
M_(k*2+1,k*2+1) = mat->rho(e,k) * vol_(k);
// - assemble element non-Galilean damping matrix
// D(m+i,n+i) += N(m) * alpha * vol * N(n);
D_(k*2 ,k*2 ) = mat->alpha(e,k) * vol_(k);
D_(k*2+1,k*2+1) = mat->alpha(e,k) * vol_(k);
}
// Gaussian quadrature
// -------------------
// pointer to element integration volume and weight
vol_.map(&vol(e));
w_ .map(&w (0));
// loop over Gauss points
for ( size_t k = 0 ; k < nip ; ++k )
{
// - pointer to the shape function gradients (local/global coordinates)
dNxi_.map(&dNxi( k));
dNx_ .map(&dNx (e,k));
// - Jacobian
// J(i,j) += dNxi(m,i) * xe(m,j)
J_(0,0) = dNxi_(0,0)*x_(0,0) + dNxi_(1,0)*x_(1,0) + dNxi_(2,0)*x_(2,0) + dNxi_(3,0)*x_(3,0);
J_(0,1) = dNxi_(0,0)*x_(0,1) + dNxi_(1,0)*x_(1,1) + dNxi_(2,0)*x_(2,1) + dNxi_(3,0)*x_(3,1);
J_(1,0) = dNxi_(0,1)*x_(0,0) + dNxi_(1,1)*x_(1,0) + dNxi_(2,1)*x_(2,0) + dNxi_(3,1)*x_(3,0);
J_(1,1) = dNxi_(0,1)*x_(0,1) + dNxi_(1,1)*x_(1,1) + dNxi_(2,1)*x_(2,1) + dNxi_(3,1)*x_(3,1);
// - determinant and inverse of the Jacobian
Jdet_ = J_.det();
Jinv_ = J_.inv();
// - integration point volume
vol_(k) = w_(k) * Jdet_;
// - shape function gradients (global coordinates)
// dNx(m,i) += Jinv(i,j) * dNxi(m,j)
for ( size_t m = 0 ; m < nne ; ++m )
{
dNx_(m,0) = Jinv_(0,0) * dNxi_(m,0) + Jinv_(0,1) * dNxi_(m,1);
dNx_(m,1) = Jinv_(1,0) * dNxi_(m,0) + Jinv_(1,1) * dNxi_(m,1);
}
}
}
// set signals
changed_f = false;
changed_M = true;
changed_D = true;
} // #pragma omp parallel
}
// =================================================================================================
template<class Material>
inline void Quad4<Material>::updated_u()
{
#pragma omp parallel
{
// intermediate quantities
cppmat::cartesian2d::tensor2 <double> gradu_;
cppmat::cartesian2d::tensor2s<double> eps_, sig_;
// local views of the global arrays (speeds up indexing, and increases readability)
cppmat::tiny::matrix2<double,4,2> dNx_, u_, f_;
cppmat::tiny::vector <double,4> vol_;
// loop over all elements (in parallel)
#pragma omp for
for ( size_t e = 0 ; e < nelem ; ++e )
{
// pointer to element forces, displacements, and integration volume
f_ .map(&f (e));
u_ .map(&u (e));
vol_.map(&vol(e));
// zero initialize forces
f_.setZero();
// loop over all integration points in element "e"
for ( size_t k = 0 ; k < nip ; ++k )
{
// - pointer to the shape function gradients, strain and stress tensor (stored symmetric)
dNx_.map(&dNx (e,k));
eps_.map(&mat->eps(e,k));
sig_.map(&mat->sig(e,k));
// - displacement gradient
// gradu_(i,j) += dNx(m,i) * ue(m,j)
gradu_(0,0) = dNx_(0,0)*u_(0,0) + dNx_(1,0)*u_(1,0) + dNx_(2,0)*u_(2,0) + dNx_(3,0)*u_(3,0);
gradu_(0,1) = dNx_(0,0)*u_(0,1) + dNx_(1,0)*u_(1,1) + dNx_(2,0)*u_(2,1) + dNx_(3,0)*u_(3,1);
gradu_(1,0) = dNx_(0,1)*u_(0,0) + dNx_(1,1)*u_(1,0) + dNx_(2,1)*u_(2,0) + dNx_(3,1)*u_(3,0);
gradu_(1,1) = dNx_(0,1)*u_(0,1) + dNx_(1,1)*u_(1,1) + dNx_(2,1)*u_(2,1) + dNx_(3,1)*u_(3,1);
// - strain (stored symmetric)
// eps(i,j) = .5 * ( gradu_(i,j) + gradu_(j,i) )
eps_(0,0) = gradu_(0,0);
eps_(0,1) = .5 * ( gradu_(0,1) + gradu_(1,0) );
eps_(1,1) = gradu_(1,1);
// - constitutive response
mat->updated_eps(e,k);
// - assemble to element force
// f(m,j) += dNx(m,i) * sig(i,j) * vol;
for ( size_t m = 0 ; m < nne ; ++m )
{
f_(m,0) += dNx_(m,0) * sig_(0,0) * vol_(k) + dNx_(m,1) * sig_(1,0) * vol_(k);
f_(m,1) += dNx_(m,0) * sig_(0,1) * vol_(k) + dNx_(m,1) * sig_(1,1) * vol_(k);
}
}
}
// set signals
changed_f = true;
changed_M = false;
changed_D = false;
}
}
// =================================================================================================
template<class Material>
inline void Quad4<Material>::updated_v()
{
#pragma omp parallel
{
// intermediate quantities
cppmat::cartesian2d::tensor2 <double> gradv_;
cppmat::cartesian2d::tensor2s<double> epsdot_, sig_;
// local views of the global arrays (speeds up indexing, and increases readability)
cppmat::tiny::matrix2<double,4,2> dNx_, v_, f_;
cppmat::tiny::vector <double,4> vol_;
// loop over all elements (in parallel)
#pragma omp for
for ( size_t e = 0 ; e < nelem ; ++e )
{
// pointer to element forces, displacements, and integration volume
f_ .map(&f (e));
v_ .map(&v (e));
vol_.map(&vol(e));
// zero initialize forces
f_.setZero();
// loop over all integration points in element "e"
for ( size_t k = 0 ; k < nip ; ++k )
{
// - pointer to the shape function gradients, strain-rate and stress tensor (stored symmetric)
dNx_ .map(&dNx (e,k));
epsdot_.map(&mat->epsdot(e,k));
sig_ .map(&mat->sig (e,k));
// - displacement gradient
// gradv_(i,j) += dNx(m,i) * ue(m,j)
gradv_(0,0) = dNx_(0,0)*v_(0,0) + dNx_(1,0)*v_(1,0) + dNx_(2,0)*v_(2,0) + dNx_(3,0)*v_(3,0);
gradv_(0,1) = dNx_(0,0)*v_(0,1) + dNx_(1,0)*v_(1,1) + dNx_(2,0)*v_(2,1) + dNx_(3,0)*v_(3,1);
gradv_(1,0) = dNx_(0,1)*v_(0,0) + dNx_(1,1)*v_(1,0) + dNx_(2,1)*v_(2,0) + dNx_(3,1)*v_(3,0);
gradv_(1,1) = dNx_(0,1)*v_(0,1) + dNx_(1,1)*v_(1,1) + dNx_(2,1)*v_(2,1) + dNx_(3,1)*v_(3,1);
// - strain (stored symmetric)
// epsdot(i,j) = .5 * ( gradv_(i,j) + gradv_(j,i) )
epsdot_(0,0) = gradv_(0,0);
epsdot_(0,1) = .5 * ( gradv_(0,1) + gradv_(1,0) );
epsdot_(1,1) = gradv_(1,1);
// - constitutive response
mat->updated_epsdot(e,k);
// - assemble to element force
// f(m,j) += dNdx(m,i) * sig(i,j) * vol;
for ( size_t m = 0 ; m < nne ; ++m )
{
f_(m,0) += dNx_(m,0) * sig_(0,0) * vol_(k) + dNx_(m,1) * sig_(1,0) * vol_(k);
f_(m,1) += dNx_(m,0) * sig_(0,1) * vol_(k) + dNx_(m,1) * sig_(1,1) * vol_(k);
}
}
}
// set signals
changed_f = true;
changed_M = false;
changed_D = false;
}
}
// =================================================================================================
template<class Material>
inline cppmat::cartesian2d::tensor2s<double> Quad4<Material>::mean_eps(size_t e)
{
cppmat::cartesian2d::tensor2s<double> eps_, tot_eps_(0.0);
cppmat::tiny::vector <double,4> vol_;
double tot_vol_ = 0.0;
// pointer to integration volume
vol_.map(&vol(e));
// loop over all integration points in element "e"
for ( size_t k = 0 ; k < nip ; ++k )
{
// - pointer to strain tensor (stored symmetric)
eps_.map(&mat->eps(e,k));
// - add to average
tot_eps_ += vol_(k) * eps_;
tot_vol_ += vol_(k);
}
// return volume average
return ( tot_eps_ / tot_vol_ );
}
// =================================================================================================
template<class Material>
inline cppmat::cartesian2d::tensor2s<double> Quad4<Material>::mean_sig(size_t e)
{
cppmat::cartesian2d::tensor2s<double> sig_, tot_sig_(0.0);
cppmat::tiny::vector <double,4> vol_;
double tot_vol_ = 0.0;
// pointer to integration volume
vol_.map(&vol(e));
// loop over all integration points in element "e"
for ( size_t k = 0 ; k < nip ; ++k )
{
// - pointer to strain tensor (stored symmetric)
sig_.map(&mat->sig(e,k));
// - add to average
tot_sig_ += vol_(k) * sig_;
tot_vol_ += vol_(k);
}
// return volume average
return ( tot_sig_ / tot_vol_ );
}
// =================================================================================================
template<class Material>
inline cppmat::cartesian2d::tensor2s<double> Quad4<Material>::mean_eps()
{
cppmat::cartesian2d::tensor2s<double> eps_, tot_eps_(0.0);
cppmat::tiny::vector <double,4> vol_;
double tot_vol_ = 0.0;
// loop over all elements (in parallel)
for ( size_t e = 0 ; e < nelem ; ++e )
{
// pointer to integration volume
vol_.map(&vol(e));
// loop over all integration points in element "e"
for ( size_t k = 0 ; k < nip ; ++k )
{
// - pointer to strain tensor (stored symmetric)
eps_.map(&mat->eps(e,k));
// - add to average
tot_eps_ += vol_(k) * eps_;
tot_vol_ += vol_(k);
}
}
// return volume average
return ( tot_eps_ / tot_vol_ );
}
// =================================================================================================
template<class Material>
inline cppmat::cartesian2d::tensor2s<double> Quad4<Material>::mean_sig()
{
cppmat::cartesian2d::tensor2s<double> sig_, tot_sig_(0.0);
cppmat::tiny::vector <double,4> vol_;
double tot_vol_ = 0.0;
// loop over all elements (in parallel)
for ( size_t e = 0 ; e < nelem ; ++e )
{
// pointer to integration volume
vol_.map(&vol(e));
// loop over all integration points in element "e"
for ( size_t k = 0 ; k < nip ; ++k )
{
// - pointer to strain tensor (stored symmetric)
sig_.map(&mat->sig(e,k));
// - add to average
tot_sig_ += vol_(k) * sig_;
tot_vol_ += vol_(k);
}
}
// return volume average
return ( tot_sig_ / tot_vol_ );
}
// -------------------------------------------------------------------------------------------------
} // namespace ...
// =================================================================================================
}}} // namespace ...
// =================================================================================================
#endif
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