Description

Class for all elements whose stiffness matrix can be seen as a NxN block-matrix to be splitted between N nodes.

Helps reducing the complexity of inherited FEA elements because it implements some bookkeeping for the interface with solver. This means that most FEA elements inherited from ChElementGeneric need to implement at most the following two fundamental methods: ComputeKRMmatricesGlobal(), ComputeInternalForces(), and optionally ComputeGravityForces().

#include <ChElementGeneric.h>

Inheritance diagram for chrono::fea::ChElementGeneric:

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Collaboration diagram for chrono::fea::ChElementGeneric:

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Public Member Functions
ChKblockGeneric &	Kstiffness ()
	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	EleIntLoadResidual_F_gravity (ChVectorDynamic<> &R, const ChVector<> &G_acc, const double c) override
	(This is a default (VERY UNOPTIMAL) book keeping so that in children classes you can avoid implementing this EleIntLoadResidual_F_gravity function, unless you need faster code. More...

virtual void	ComputeGravityForces (ChVectorDynamic<> &Fg, const ChVector<> &G_acc) override
	(This is the default implementation (POTENTIALLY INEFFICIENT) so that in children classes you can avoid implementing this ComputeGravityForces() function, unless you need faster code.) This fallback implementation uses a temp ChLoaderGravity that applies the load to elements only if they are inherited by ChLoadableUVW so it can use GetDensity() and Gauss quadrature.

virtual void	ComputeMmatrixGlobal (ChMatrixRef M) override
	Returns the global mass matrix. More...

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 int	GetNnodes ()=0
	Gets the number of nodes used by this element.

virtual int	GetNdofs ()=0
	Gets the number of coordinates in the field used by the referenced nodes. More...

virtual int	GetNodeNdofs (int n)=0
	Get the number of coordinates from the n-th node that are used by this element. More...

virtual std::shared_ptr< ChNodeFEAbase >	GetNodeN (int n)=0
	Access the nth node.

virtual void	GetStateBlock (ChVectorDynamic<> &mD)=0
	Fills the D vector with the current field values at the nodes of the element, with proper ordering. More...

virtual void	ComputeNodalMass ()
	Compute element's nodal masses.

virtual void	ComputeKRMmatricesGlobal (ChMatrixRef H, double Kfactor, double Rfactor=0, double Mfactor=0)=0
	Sets H as the stiffness matrix K, scaled by Kfactor. More...

virtual void	ComputeInternalForces (ChVectorDynamic<> &Fi)=0
	Computes the internal forces (ex. More...

virtual void	Update ()
	Update: this is called at least at each time step. More...

virtual void	EleDoIntegration ()
	This is optionally implemented if there is some internal state that requires integration.

Protected Attributes
ChKblockGeneric	Kmatr

Member Function Documentation

◆ ComputeMmatrixGlobal()

virtual void chrono::fea::ChElementGeneric::ComputeMmatrixGlobal ( ChMatrixRef M )

inlineoverridevirtual

Returns the global mass matrix.

This is the default implementation, POTENTIALLY VERY INEFFICIENT. Children classes may need to override this with a more efficient version.

Implements chrono::fea::ChElementBase.

Reimplemented in chrono::fea::ChElementShellReissner4, chrono::fea::ChElementShellANCF_8, chrono::fea::ChElementShellANCF, chrono::fea::ChElementBeamANCF, and chrono::fea::ChElementCableANCF.

◆ EleIntLoadResidual_F_gravity()

void chrono::fea::ChElementGeneric::EleIntLoadResidual_F_gravity	(	ChVectorDynamic<> &	R,
		const ChVector<> &	G_acc,
		const double	c
	)

overridevirtual

(This is a default (VERY UNOPTIMAL) book keeping so that in children classes you can avoid implementing this EleIntLoadResidual_F_gravity function, unless you need faster code.

This fallback implementation uses a temp ChLoaderGravity that applies the load to elements only if they are inherited by ChLoadableUVW so it can use GetDensity() and Gauss quadrature.

Implements chrono::fea::ChElementBase.

◆ KRMmatricesLoad()

virtual void chrono::fea::ChElementGeneric::KRMmatricesLoad	(	double	Kfactor,
		double	Rfactor,
		double	Mfactor
	)

inlineoverridevirtual

Adds the current stiffness K and damping R and mass M matrices in encapsulated ChKblock item(s), if any.

The K, R, M matrices are load with scaling values Kfactor, Rfactor, Mfactor.

Implements chrono::fea::ChElementBase.

◆ VariablesFbIncrementMq()

void chrono::fea::ChElementGeneric::VariablesFbIncrementMq ( )

overridevirtual

Adds M*q (internal masses multiplied current 'qb') to Fb, ex.

if qb is initialized with v_old using VariablesQbLoadSpeed, this method can be used in timestepping schemes that do: M*v_new = M*v_old + forces*dt (This is a default (VERY UNOPTIMAL) book keeping so that in children classes you can avoid implementing this VariablesFbIncrementMq function, unless you need faster code.)

Reimplemented from chrono::fea::ChElementBase.

The documentation for this class was generated from the following files:

/builds/uwsbel/chrono/src/chrono/fea/ChElementGeneric.h
/builds/uwsbel/chrono/src/chrono/fea/ChElementGeneric.cpp

Description

Public Member Functions

Protected Attributes

Member Function Documentation

◆ ComputeMmatrixGlobal()

◆ EleIntLoadResidual_F_gravity()

◆ KRMmatricesLoad()

◆ VariablesFbIncrementMq()