chrono::fea::ChElementBrick Class Reference

Description

Brick element with 8 nodes (with EAS).

#include <ChElementBrick.h>

Inheritance diagram for chrono::fea::ChElementBrick:
Collaboration diagram for chrono::fea::ChElementBrick:

Classes

class  MyForceAnalytical
 Internal force, EAS stiffness, and analytical jacobian are calculated. More...
 
class  MyGravity
 Class to calculate the gravity forces of a brick element. More...
 

Public Member Functions

virtual int GetNnodes () override
 Get number of nodes of this element.
 
virtual int GetNdofs () override
 Get number of degrees of freedom of this element.
 
virtual int GetNodeNdofs (int n) override
 Get the number of coordinates from the n-th node used by this element.
 
virtual std::shared_ptr
< ChNodeFEAbase
GetNodeN (int n) override
 Access the n-th node of this element.
 
void SetNodes (std::shared_ptr< ChNodeFEAxyz > nodeA, std::shared_ptr< ChNodeFEAxyz > nodeB, std::shared_ptr< ChNodeFEAxyz > nodeC, std::shared_ptr< ChNodeFEAxyz > nodeD, std::shared_ptr< ChNodeFEAxyz > nodeE, std::shared_ptr< ChNodeFEAxyz > nodeF, std::shared_ptr< ChNodeFEAxyz > nodeG, std::shared_ptr< ChNodeFEAxyz > nodeH)
 Specify the nodes of this element.
 
void SetElemNum (int kb)
 Set the element number.
 
void SetStockAlpha (double a1, double a2, double a3, double a4, double a5, double a6, double a7, double a8, double a9)
 Set EAS internal parameters (stored values).
 
void SetStockJac (const ChMatrixNM< double, 24, 24 > &a)
 Set EAS Jacobian matrix.
 
void SetStockKTE (const ChMatrixNM< double, 24, 24 > &a)
 Set Analytical Jacobian.
 
void SetInertFlexVec (const ChMatrixNM< double, 3, 1 > &a)
 Set some element parameters (dimensions).
 
int GetElemNum () const
 
const ChMatrixNM< double, 8, 3 > & GetInitialPos () const
 Get initial position of the element in matrix form.
 
std::shared_ptr< ChNodeFEAxyzGetNodeA () const
 
std::shared_ptr< ChNodeFEAxyzGetNodeB () const
 
std::shared_ptr< ChNodeFEAxyzGetNodeC () const
 
std::shared_ptr< ChNodeFEAxyzGetNodeD () const
 
std::shared_ptr< ChNodeFEAxyzGetNodeE () const
 
std::shared_ptr< ChNodeFEAxyzGetNodeF () const
 
std::shared_ptr< ChNodeFEAxyzGetNodeG () const
 
std::shared_ptr< ChNodeFEAxyzGetNodeH () const
 
double GetLengthX () const
 
double GetLengthY () const
 
double GetLengthZ () const
 
void SetMaterial (std::shared_ptr< ChContinuumElastic > my_material)
 
std::shared_ptr
< ChContinuumElastic
GetMaterial () const
 
void SetGravityOn (bool val)
 Turn gravity on/off.
 
void SetMooneyRivlin (bool val)
 Set whether material is Mooney-Rivlin (Otherwise linear elastic isotropic)
 
void SetMRCoefficients (double C1, double C2)
 Set Mooney-Rivlin coefficients.
 
void ShapeFunctions (ChMatrix<> &N, double x, double y, double z)
 Fills the N shape function matrix as N = [s1*eye(3) s2*eye(3) s3*eye(3) s4*eye(3)...]; ,.
 
void ShapeFunctionsDerivativeX (ChMatrix<> &Nx, double x, double y, double z)
 
void ShapeFunctionsDerivativeY (ChMatrix<> &Ny, double x, double y, double z)
 
void ShapeFunctionsDerivativeZ (ChMatrix<> &Nz, double x, double y, double z)
 
virtual int LoadableGet_ndof_x () override
 Gets the number of DOFs affected by this element (position part)
 
virtual int LoadableGet_ndof_w () override
 Gets the number of DOFs affected by this element (speed part)
 
virtual void LoadableGetStateBlock_x (int block_offset, ChState &mD) override
 Gets all the DOFs packed in a single vector (position part)
 
virtual void LoadableGetStateBlock_w (int block_offset, ChStateDelta &mD) override
 Gets all the DOFs packed in a single vector (speed 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 int Get_field_ncoords () override
 Number of coordinates in the interpolated field: here the {x,y,z} displacement.
 
virtual int GetSubBlocks () override
 Tell the number of DOFs blocks (ex. =1 for a body, =4 for a tetrahedron, etc.)
 
virtual unsigned int GetSubBlockOffset (int nblock) override
 Get the offset of the i-th sub-block of DOFs in global vector.
 
virtual unsigned int GetSubBlockSize (int nblock) override
 Get the size of the i-th sub-block of DOFs in global vector.
 
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, 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.
 
- Public Member Functions inherited from chrono::fea::ChElementGeneric
ChKblockGenericKstiffness ()
 Access the proxy to stiffness, for sparse solver.
 
virtual void EleIntLoadResidual_F (ChVectorDynamic<> &R, const double c) override
 (This is a default (a bit unoptimal) book keeping so that in children classes you can avoid implementing this EleIntLoadResidual_F function, unless you need faster code)
 
virtual void EleIntLoadResidual_Mv (ChVectorDynamic<> &R, const ChVectorDynamic<> &w, const double c) override
 (This is a default (VERY UNOPTIMAL) book keeping so that in children classes you can avoid implementing this EleIntLoadResidual_Mv function, unless you need faster code.)
 
virtual void InjectKRMmatrices (ChSystemDescriptor &mdescriptor) override
 Tell to a system descriptor that there are item(s) of type ChKblock in this object (for further passing it to a solver)
 
virtual void KRMmatricesLoad (double Kfactor, double Rfactor, double Mfactor) override
 Adds the current stiffness K and damping R and mass M matrices in encapsulated ChKblock item(s), if any. More...
 
virtual void VariablesFbLoadInternalForces (double factor=1.) override
 Adds the internal forces, expressed as nodal forces, into the encapsulated ChVariables, in the 'fb' part: qf+=forces*factor (This is a default (a bit unoptimal) book keeping so that in children classes you can avoid implementing this VariablesFbLoadInternalForces function, unless you need faster code)
 
virtual void VariablesFbIncrementMq () override
 Adds M*q (internal masses multiplied current 'qb') to Fb, ex. More...
 
- Public Member Functions inherited from chrono::fea::ChElementBase
virtual void ComputeNodalMass ()
 Compute element's nodal masses.
 
- 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 quadrature over u,v,w in [-1..+1] as box isoparametric coords. More...
 

Additional Inherited Members

- Protected Attributes inherited from chrono::fea::ChElementGeneric
ChKblockGeneric Kmatr
 

Member Function Documentation

virtual void chrono::fea::ChElementBrick::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.

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.