Description

ANCF laminated shell element with four nodes.

This class implements composite material elastic force formulations.

The node numbering is in ccw fashion as in the following scheme:

        v
        ^
        |
D o-----+-----o C
  |     |     |
--+-----+-----+----> u
  |     |     |
A o-----+-----o B

#include <ChElementShellANCF_3423.h>

Inheritance diagram for chrono::fea::ChElementShellANCF_3423:
Collaboration diagram for chrono::fea::ChElementShellANCF_3423:

Classes

class  Layer
 Definition of a layer. More...
 

Public Types

using ShapeVector = ChMatrixNM< double, 1, NSF >
 
using VectorN = ChVectorN< double, NSF >
 
using MatrixNx3 = ChMatrixNM< double, NSF, 3 >
 

Public Member Functions

virtual unsigned int GetNumNodes () override
 Get the number of nodes used by this element.
 
virtual unsigned int GetNumCoordsPosLevel () override
 Get the number of coordinates in the field used by the referenced nodes.
 
virtual unsigned int GetNumCoordsPosLevelActive () override
 Get the number of active coordinates in the field used by the referenced nodes.
 
virtual unsigned int GetNodeNumCoordsPosLevel (unsigned int n) override
 Get the number of coordinates from the n-th node used by this element.
 
virtual unsigned int GetNodeNumCoordsPosLevelActive (unsigned int n) override
 Get the number of active coordinates from the n-th node used by this element.
 
void SetNodes (std::shared_ptr< ChNodeFEAxyzD > nodeA, std::shared_ptr< ChNodeFEAxyzD > nodeB, std::shared_ptr< ChNodeFEAxyzD > nodeC, std::shared_ptr< ChNodeFEAxyzD > nodeD)
 Specify the nodes of this element.
 
void SetDimensions (double lenX, double lenY)
 Specify the element dimensions.
 
virtual std::shared_ptr< ChNodeFEAbaseGetNode (unsigned int n) override
 Access the n-th node of this element.
 
std::shared_ptr< ChNodeFEAxyzDGetNodeA () const
 Get a handle to the first node of this element.
 
std::shared_ptr< ChNodeFEAxyzDGetNodeB () const
 Get a handle to the second node of this element.
 
std::shared_ptr< ChNodeFEAxyzDGetNodeC () const
 Get a handle to the third node of this element.
 
std::shared_ptr< ChNodeFEAxyzDGetNodeD () const
 Get a handle to the fourth node of this element.
 
void AddLayer (double thickness, double theta, std::shared_ptr< ChMaterialShellANCF > material)
 Add a layer. More...
 
size_t GetNumLayers () const
 Get the number of layers.
 
const LayerGetLayer (size_t i) const
 Get a handle to the specified layer.
 
void SetAlphaDamp (double a)
 Set the structural damping.
 
double GetLengthX () const
 Get the element length in the X direction.
 
double GetLengthY () const
 Get the element length in the Y direction.
 
double GetThickness ()
 Get the total thickness of the shell element.
 
void ShapeFunctions (ShapeVector &N, double x, double y, double z)
 Fills the N shape function matrix. More...
 
void ShapeFunctionsDerivativeX (ShapeVector &Nx, double x, double y, double z)
 Fills the Nx shape function derivative matrix with respect to X. More...
 
void ShapeFunctionsDerivativeY (ShapeVector &Ny, double x, double y, double z)
 Fills the Ny shape function derivative matrix with respect to Y. More...
 
void ShapeFunctionsDerivativeZ (ShapeVector &Nz, double x, double y, double z)
 Fills the Nz shape function derivative matrix with respect to Z. More...
 
ChStrainStress3D EvaluateSectionStrainStress (const ChVector3d &loc, int layer_id)
 Return a struct with 6-component strain and stress vectors evaluated at a given quadrature point and layer number. More...
 
void EvaluateDeflection (double &defVec)
 
virtual void GetStateBlock (ChVectorDynamic<> &mD) override
 Fill the D vector with the current field values at the nodes of the element, with proper ordering. More...
 
virtual void ComputeKRMmatricesGlobal (ChMatrixRef H, double Kfactor, double Rfactor=0, double Mfactor=0) override
 Set H as the stiffness matrix K, scaled by Kfactor. More...
 
virtual void ComputeMmatrixGlobal (ChMatrixRef M) override
 Set M as the global mass matrix.
 
virtual void ComputeNodalMass () override
 Add contribution of element inertia to total nodal masses. More...
 
virtual void ComputeGravityForces (ChVectorDynamic<> &Fg, const ChVector3d &G_acc) override
 Compute the generalized force vector due to gravity using the efficient ANCF specific method.
 
virtual void ComputeInternalForces (ChVectorDynamic<> &Fi) override
 Computes the internal forces. More...
 
virtual void Update () override
 Update the state of this element.
 
virtual void EvaluateSectionDisplacement (const double u, const double v, ChVector3d &u_displ, ChVector3d &u_rotaz) override
 Gets the xyz displacement of a point on the shell, and the rotation RxRyRz of section reference, at parametric coordinates 'u' and 'v'. More...
 
virtual void EvaluateSectionFrame (const double u, const double v, ChVector3d &point, ChQuaternion<> &rot) override
 Gets the absolute xyz position of a point on the shell, and the absolute rotation of section reference, at parametric coordinates 'u' and 'v'. More...
 
virtual void EvaluateSectionPoint (const double u, const double v, ChVector3d &point) override
 Gets the absolute xyz position of a point on the shell, at parametric coordinates 'u' and 'v'. More...
 
void ComputeInternalJacobians (double Kfactor, double Rfactor)
 Compute Jacobians of the internal forces. More...
 
void ComputeMassMatrix ()
 Compute the mass matrix of the element. More...
 
void ComputeGravityForceScale ()
 Compute the matrix to scale gravity by to get the generalized gravitational force.
 
void ShapeFunctionANSbilinearShell (ChMatrixNM< double, 1, 4 > &S_ANS, double x, double y)
 
void CalcStrainANSbilinearShell ()
 
void Basis_M (ChMatrixNM< double, 6, 5 > &M, double x, double y, double z)
 
double Calc_detJ0 (double x, double y, double z)
 
double Calc_detJ0 (double x, double y, double z, ShapeVector &Nx, ShapeVector &Ny, ShapeVector &Nz, ChMatrixNM< double, 1, 3 > &Nx_d0, ChMatrixNM< double, 1, 3 > &Ny_d0, ChMatrixNM< double, 1, 3 > &Nz_d0)
 
void CalcCoordMatrix (ChMatrixNM< double, 8, 3 > &d)
 
void CalcCoordDtMatrix (ChVectorN< double, 24 > &dt)
 
virtual unsigned int GetLoadableNumCoordsPosLevel () override
 Gets the number of DOFs affected by this element (position part).
 
virtual unsigned int GetLoadableNumCoordsVelLevel () override
 Gets the number of DOFs affected by this element (velocity part).
 
virtual void LoadableGetStateBlockPosLevel (int block_offset, ChState &mD) override
 Gets all the DOFs packed in a single vector (position part).
 
virtual void LoadableGetStateBlockVelLevel (int block_offset, ChStateDelta &mD) override
 Gets all the DOFs packed in a single vector (velocity part).
 
virtual void LoadableStateIncrement (const unsigned int off_x, ChState &x_new, const ChState &x, const unsigned int off_v, const ChStateDelta &Dv) override
 Increment all DOFs using a delta.
 
virtual unsigned int GetNumFieldCoords () override
 Number of coordinates in the interpolated field, ex=3 for a tetrahedron finite element or a cable, = 1 for a thermal problem, etc.
 
virtual unsigned int GetNumSubBlocks () override
 Get the number of DOFs sub-blocks.
 
virtual unsigned int GetSubBlockOffset (unsigned int nblock) override
 Get the offset of the specified sub-block of DOFs in global vector.
 
virtual unsigned int GetSubBlockSize (unsigned int nblock) override
 Get the size of the specified sub-block of DOFs in global vector.
 
virtual bool IsSubBlockActive (unsigned int nblock) const override
 Check if the specified sub-block of DOFs is active.
 
virtual void EvaluateSectionVelNorm (double U, double V, ChVector3d &Result) override
 Virtual method to plot velocity field distribution. More...
 
virtual void LoadableGetVariables (std::vector< ChVariables * > &mvars) override
 Get the pointers to the contained ChVariables, appending to the mvars vector.
 
virtual void ComputeNF (const double U, const double V, ChVectorDynamic<> &Qi, double &detJ, const ChVectorDynamic<> &F, ChVectorDynamic<> *state_x, ChVectorDynamic<> *state_w) override
 Evaluate N'*F , where N is some type of shape function evaluated at U,V coordinates of the surface, each ranging in -1..+1 F is a load, N'*F is the resulting generalized load Returns also det[J] with J=[dx/du,..], that might be useful in gauss quadrature. More...
 
virtual void ComputeNF (const double U, const double V, const double W, ChVectorDynamic<> &Qi, double &detJ, const ChVectorDynamic<> &F, ChVectorDynamic<> *state_x, ChVectorDynamic<> *state_w) override
 Evaluate N'*F , where N is some type of shape function evaluated at U,V,W coordinates of the volume, each ranging in -1..+1 F is a load, N'*F is the resulting generalized load Returns also det[J] with J=[dx/du,..], that might be useful in gauss quadrature. More...
 
virtual double GetDensity () override
 This is needed so that it can be accessed by ChLoaderVolumeGravity. More...
 
virtual ChVector3d ComputeNormal (const double U, const double V) override
 Gets the normal to the surface at the parametric coordinate U,V. More...
 
- Public Member Functions inherited from chrono::fea::ChElementShell
virtual bool IsTriangleShell ()
 Return false if quadrilateral shell - hence u,v parametric coordinates assumed in -1..+1, return true if triangular shell - hence u,v are triangle natural coordinates assumed in 0..+1.
 
- Public Member Functions inherited from chrono::fea::ChElementGeneric
ChKRMBlockKstiffness ()
 Access the proxy to stiffness, for sparse solver.
 
virtual void EleIntLoadResidual_F (ChVectorDynamic<> &R, const double c) override
 Add the internal forces (pasted at global nodes offsets) into a global vector R, multiplied by a scaling factor c, as R += forces * c This default implementation is SLIGHTLY INEFFICIENT.
 
virtual void EleIntLoadResidual_Mv (ChVectorDynamic<> &R, const ChVectorDynamic<> &w, const double c) override
 Add the product of element mass M by a vector w (pasted at global nodes offsets) into a global vector R, multiplied by a scaling factor c, as R += M * w * c This default implementation is VERY INEFFICIENT.
 
virtual void EleIntLoadLumpedMass_Md (ChVectorDynamic<> &Md, double &error, const double c) override
 Adds the lumped mass to a Md vector, representing a mass diagonal matrix. More...
 
virtual void EleIntLoadResidual_F_gravity (ChVectorDynamic<> &R, const ChVector3d &G_acc, const double c) override
 Add the contribution of gravity loads, multiplied by a scaling factor c, as: R += M * g * c This default implementation is VERY INEFFICIENT. More...
 
virtual void InjectKRMMatrices (ChSystemDescriptor &descriptor) override
 Register with the given system descriptor any ChKRMBlock objects associated with this item.
 
virtual void LoadKRMMatrices (double Kfactor, double Rfactor, double Mfactor) override
 Compute and load current stiffnes (K), damping (R), and mass (M) matrices in encapsulated ChKRMBlock objects. More...
 
virtual void VariablesFbLoadInternalForces (double factor=1.) override
 Add the internal forces, expressed as nodal forces, into the encapsulated ChVariables.
 
virtual void VariablesFbIncrementMq () override
 Add M*q (internal masses multiplied current 'qb').
 
- Public Member Functions inherited from chrono::fea::ChElementBase
virtual void EleDoIntegration ()
 This is optionally implemented if there is some internal state that requires integration.
 
- Public Member Functions inherited from chrono::ChLoadableUV
virtual bool IsTriangleIntegrationNeeded ()
 If true, use quadrature over u,v in [0..1] range as triangle area coords (with z=1-u-v) otherwise use default quadrature over u,v in [-1..+1] as rectangular isoparametric coords.
 
- Public Member Functions inherited from chrono::ChLoadableUVW
virtual bool IsTetrahedronIntegrationNeeded ()
 If true, use quadrature over u,v,w in [0..1] range as tetrahedron volumetric coords (with z=1-u-v-w) otherwise use default quadrature over u,v,w in [-1..+1] as box isoparametric coords.
 
virtual bool IsTrianglePrismIntegrationNeeded ()
 If true, use quadrature over u,v in [0..1] range as triangle natural coords (with z=1-u-v), and use linear quadrature over w in [-1..+1], otherwise use default quadrature over u,v,w in [-1..+1] as box isoparametric coords.
 

Static Public Attributes

static const int NSF = 8
 number of shape functions
 

Friends

class ShellANCF_Mass
 
class ShellANCF_Gravity
 
class ShellANCF_Force
 
class ShellANCF_Jacobian
 

Additional Inherited Members

- Protected Attributes inherited from chrono::fea::ChElementANCF
int m_element_dof
 actual number of degrees of freedom for the element
 
bool m_full_dof
 true if all node variables are active (not fixed)
 
ChArray< int > m_mapping_dof
 indices of active DOFs (set only is some are fixed)
 
- Protected Attributes inherited from chrono::fea::ChElementShell
double mass
 
- Protected Attributes inherited from chrono::fea::ChElementGeneric
ChKRMBlock Kmatr
 

Member Function Documentation

◆ AddLayer()

void chrono::fea::ChElementShellANCF_3423::AddLayer ( double  thickness,
double  theta,
std::shared_ptr< ChMaterialShellANCF material 
)

Add a layer.

Parameters
thicknesslayer thickness
thetafiber angle (radians)
materiallayer material

◆ ComputeInternalForces()

void chrono::fea::ChElementShellANCF_3423::ComputeInternalForces ( ChVectorDynamic<> &  Fi)
overridevirtual

Computes the internal forces.

(E.g. the actual position of nodes is not in relaxed reference position) and set values in the Fi vector.

Implements chrono::fea::ChElementBase.

◆ ComputeInternalJacobians()

void chrono::fea::ChElementShellANCF_3423::ComputeInternalJacobians ( double  Kfactor,
double  Rfactor 
)

Compute Jacobians of the internal forces.

This function calculates a linear combination of the stiffness (K) and damping (R) matrices, J = Kfactor * K + Rfactor * R for given coefficients Kfactor and Rfactor. This Jacobian will be further combined with the global mass matrix M and included in the global stiffness matrix H in the function ComputeKRMmatricesGlobal().

◆ ComputeKRMmatricesGlobal()

void chrono::fea::ChElementShellANCF_3423::ComputeKRMmatricesGlobal ( ChMatrixRef  H,
double  Kfactor,
double  Rfactor = 0,
double  Mfactor = 0 
)
overridevirtual

Set H as the stiffness matrix K, scaled by Kfactor.

Optionally, also superimposes global damping matrix R, scaled by Rfactor, and mass matrix M, scaled by Mfactor. Matrices are expressed in global reference. Corotational elements can take the local Kl & Rl matrices and rotate them.

Implements chrono::fea::ChElementBase.

◆ ComputeMassMatrix()

void chrono::fea::ChElementShellANCF_3423::ComputeMassMatrix ( )

Compute the mass matrix of the element.

Note: in this 'basic' implementation, constant section and constant material are assumed

◆ ComputeNF() [1/2]

void chrono::fea::ChElementShellANCF_3423::ComputeNF ( const double  U,
const double  V,
ChVectorDynamic<> &  Qi,
double &  detJ,
const ChVectorDynamic<> &  F,
ChVectorDynamic<> *  state_x,
ChVectorDynamic<> *  state_w 
)
overridevirtual

Evaluate N'*F , where N is some type of shape function evaluated at U,V coordinates of the surface, each ranging in -1..+1 F is a load, N'*F is the resulting generalized load Returns also det[J] with J=[dx/du,..], that might be useful in gauss quadrature.

For this ANCF element, only the first 6 entries in F are used in the calculation. The first three entries is the applied force in global coordinates and the second 3 entries is the applied moment in global space.

Parameters
Uparametric coordinate in surface
Vparametric coordinate in surface
QiReturn result of Q = N'*F here
detJReturn det[J] here
FInput F vector, size is =n. field coords.
state_xif != 0, update state (pos. part) to this, then evaluate Q
state_wif != 0, update state (speed part) to this, then evaluate Q

Implements chrono::ChLoadableUV.

◆ ComputeNF() [2/2]

void chrono::fea::ChElementShellANCF_3423::ComputeNF ( const double  U,
const double  V,
const double  W,
ChVectorDynamic<> &  Qi,
double &  detJ,
const ChVectorDynamic<> &  F,
ChVectorDynamic<> *  state_x,
ChVectorDynamic<> *  state_w 
)
overridevirtual

Evaluate N'*F , where N is some type of shape function evaluated at U,V,W coordinates of the volume, each ranging in -1..+1 F is a load, N'*F is the resulting generalized load Returns also det[J] with J=[dx/du,..], that might be useful in gauss quadrature.

For this ANCF element, only the first 6 entries in F are used in the calculation. The first three entries is the applied force in global coordinates and the second 3 entries is the applied moment in global space.

Parameters
Uparametric coordinate in volume
Vparametric coordinate in volume
Wparametric coordinate in volume
QiReturn result of N'*F here, maybe with offset block_offset
detJReturn det[J] here
FInput F vector, size is = n.field coords.
state_xif != 0, update state (pos. part) to this, then evaluate Q
state_wif != 0, update state (speed part) to this, then evaluate Q

Implements chrono::ChLoadableUVW.

◆ ComputeNodalMass()

void chrono::fea::ChElementShellANCF_3423::ComputeNodalMass ( )
overridevirtual

Add contribution of element inertia to total nodal masses.

This class computes and adds corresponding masses to ElementGeneric member m_TotalMass.

Reimplemented from chrono::fea::ChElementBase.

◆ ComputeNormal()

ChVector3d chrono::fea::ChElementShellANCF_3423::ComputeNormal ( const double  U,
const double  V 
)
overridevirtual

Gets the normal to the surface at the parametric coordinate U,V.

Each coordinate ranging in -1..+1.

Implements chrono::ChLoadableUV.

◆ EvaluateSectionDisplacement()

void chrono::fea::ChElementShellANCF_3423::EvaluateSectionDisplacement ( const double  u,
const double  v,
ChVector3d u_displ,
ChVector3d u_rotaz 
)
overridevirtual

Gets the xyz displacement of a point on the shell, and the rotation RxRyRz of section reference, at parametric coordinates 'u' and 'v'.

Note, u=-1..+1 , v= -1..+1 parametric coordinates, except if triangular shell, where u=0..+1, v=0..+1, natural triangle coords. Results are not corotated.

Implements chrono::fea::ChElementShell.

◆ EvaluateSectionFrame()

void chrono::fea::ChElementShellANCF_3423::EvaluateSectionFrame ( const double  u,
const double  v,
ChVector3d point,
ChQuaternion<> &  rot 
)
overridevirtual

Gets the absolute xyz position of a point on the shell, and the absolute rotation of section reference, at parametric coordinates 'u' and 'v'.

Note, u=-1..+1 , v= -1..+1 parametric coordinates, except if triangular shell, where u=0..+1, v=0..+1, natural triangle coords. Results are corotated.

Implements chrono::fea::ChElementShell.

◆ EvaluateSectionPoint()

void chrono::fea::ChElementShellANCF_3423::EvaluateSectionPoint ( const double  u,
const double  v,
ChVector3d point 
)
overridevirtual

Gets the absolute xyz position of a point on the shell, at parametric coordinates 'u' and 'v'.

Note, u=-1..+1 , v= -1..+1 parametric coordinates, except if triangular shell, where u=0..+1, v=0..+1, natural triangle coords. Results are corotated.

Implements chrono::fea::ChElementShell.

◆ EvaluateSectionStrainStress()

ChStrainStress3D chrono::fea::ChElementShellANCF_3423::EvaluateSectionStrainStress ( const ChVector3d loc,
int  layer_id 
)

Return a struct with 6-component strain and stress vectors evaluated at a given quadrature point and layer number.

Beta

◆ EvaluateSectionVelNorm()

void chrono::fea::ChElementShellANCF_3423::EvaluateSectionVelNorm ( double  U,
double  V,
ChVector3d Result 
)
overridevirtual

Virtual method to plot velocity field distribution.

Note, u=-1..+1 , v= -1..+1 parametric coordinates, except if triangular shell, where u=0..+1, v=0..+1, natural triangle coords.

Implements chrono::fea::ChElementShell.

◆ GetDensity()

double chrono::fea::ChElementShellANCF_3423::GetDensity ( )
overridevirtual

This is needed so that it can be accessed by ChLoaderVolumeGravity.

Density is mass per unit surface.

Implements chrono::ChLoadableUVW.

◆ GetStateBlock()

void chrono::fea::ChElementShellANCF_3423::GetStateBlock ( ChVectorDynamic<> &  mD)
overridevirtual

Fill the D vector with the current field values at the nodes of the element, with proper ordering.

If the D vector has not the size of this->GetNumCoordsPosLevel(), it will be resized. {x_a y_a z_a Dx_a Dx_a Dx_a x_b y_b z_b Dx_b Dy_b Dz_b}

Implements chrono::fea::ChElementBase.

◆ ShapeFunctions()

void chrono::fea::ChElementShellANCF_3423::ShapeFunctions ( ShapeVector &  N,
double  x,
double  y,
double  z 
)

Fills the N shape function matrix.

NOTE! actually N should be a 3row, 24 column sparse matrix, as N = [s1*eye(3) s2*eye(3) s3*eye(3) s4*eye(3)...]; , but to avoid wasting zero and repeated elements, here it stores only the s1 through s8 values in a 1 row, 8 columns matrix!

◆ ShapeFunctionsDerivativeX()

void chrono::fea::ChElementShellANCF_3423::ShapeFunctionsDerivativeX ( ShapeVector &  Nx,
double  x,
double  y,
double  z 
)

Fills the Nx shape function derivative matrix with respect to X.

NOTE! to avoid wasting zero and repeated elements, here it stores only the four values in a 1 row, 8 columns matrix!

◆ ShapeFunctionsDerivativeY()

void chrono::fea::ChElementShellANCF_3423::ShapeFunctionsDerivativeY ( ShapeVector &  Ny,
double  x,
double  y,
double  z 
)

Fills the Ny shape function derivative matrix with respect to Y.

NOTE! to avoid wasting zero and repeated elements, here it stores only the four values in a 1 row, 8 columns matrix!

◆ ShapeFunctionsDerivativeZ()

void chrono::fea::ChElementShellANCF_3423::ShapeFunctionsDerivativeZ ( ShapeVector &  Nz,
double  x,
double  y,
double  z 
)

Fills the Nz shape function derivative matrix with respect to Z.

NOTE! to avoid wasting zero and repeated elements, here it stores only the four values in a 1 row, 8 columns matrix!


The documentation for this class was generated from the following files:
  • /builds/uwsbel/chrono/src/chrono/fea/ChElementShellANCF_3423.h
  • /builds/uwsbel/chrono/src/chrono/fea/ChElementShellANCF_3423.cpp