Description

Base class for loads representing a concentrated wrench (force + torque) acting on a ChNodeFEAxyzrot.

Users should inherit from this and implement custom ComputeForceTorque(), this is enough to have the load working. Note: there are already some predefined examples, i.e. children classes with common concrete implementations, such as ChLoadXYZROTnodeForceAbsolute; take inspiration from those example to inherit your own load if they are not enough.

#include <ChLoadsXYZROTnode.h>

Inheritance diagram for chrono::fea::ChLoadXYZROTnode:

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Collaboration diagram for chrono::fea::ChLoadXYZROTnode:

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Public Member Functions
	ChLoadXYZROTnode (std::shared_ptr< ChNodeFEAxyzrot > body)

virtual void	ComputeForceTorque (const ChFrameMoving<> &node_frame_abs_pos_vel, ChVector<> &abs_force, ChVector<> &abs_torque)=0
	Compute the force and torque on the node, in absolute coordsystem, given absolute position and speed of node passed via node_frame_abs_pos_vel. More...

virtual void	ComputeQ (ChState state_x, ChStateDelta state_w) override
	Compute Q, the generalized load. More...

ChVector	GetForce () const
	For diagnosis purposes, this can return the actual last computed value of the applied force, expressed in absolute coordinate system, assumed applied to node.

ChVector	GetTorque () const
	For diagnosis purposes, this can return the actual last computed value of the applied torque, expressed in absolute coordinate system, assumed applied to node.

Public Member Functions inherited from chrono::ChLoadCustom
	ChLoadCustom (std::shared_ptr< ChLoadable > mloadable)

virtual int	LoadGet_ndof_x () override
	Gets the number of DOFs affected by this load (position part)

virtual int	LoadGet_ndof_w () override
	Gets the number of DOFs affected by this load (speed part)

virtual void	LoadGetStateBlock_x (ChState &mD) override
	Gets all the current DOFs packed in a single vector (position part)

virtual void	LoadGetStateBlock_w (ChStateDelta &mD) override
	Gets all the current DOFs packed in a single vector (speed part)

virtual void	LoadStateIncrement (const ChState &x, const ChStateDelta &dw, ChState &x_new) override
	Increment a packed state (ex. More...

virtual int	LoadGet_field_ncoords () 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 void	ComputeJacobian (ChState state_x, ChStateDelta state_w, ChMatrixRef mK, ChMatrixRef mR, ChMatrixRef mM) override
	Compute jacobians (default fallback). More...

virtual void	LoadIntLoadResidual_F (ChVectorDynamic<> &R, double c) override
	Adds the internal loads Q (pasted at global nodes offsets) into a global vector R, multiplied by a scaling factor c, as R += forces * c.

virtual void	LoadIntLoadResidual_Mv (ChVectorDynamic<> &R, const ChVectorDynamic<> &w, double c) override
	Default fallback: compute jacobians via ComputeJacobian(), then use M=-dQ/da to do R += cMw. More...

virtual void	CreateJacobianMatrices () override
	Create the jacobian loads if needed, and also set the ChVariables referenced by the sparse KRM block.

virtual ChVectorDynamic &	GetQ ()
	Access the generalized load vector Q.

Public Member Functions inherited from chrono::ChLoadBase
ChLoadJacobians *	GetJacobians ()
	Access the jacobians (if any, i.e. if this is a stiff load)

virtual void	InjectKRMmatrices (ChSystemDescriptor &mdescriptor)
	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)
	Adds the current stiffness K and damping R and mass M matrices in encapsulated ChKblock item(s), if any. More...

Public Member Functions inherited from chrono::ChObj
	ChObj (const ChObj &other)

virtual ChObj *	Clone () const =0
	"Virtual" copy constructor. More...

int	GetIdentifier () const
	Gets the numerical identifier of the object.

void	SetIdentifier (int id)
	Sets the numerical identifier of the object.

double	GetChTime () const
	Gets the simulation time of this object.

void	SetChTime (double m_time)
	Sets the simulation time of this object.

const char *	GetName () const
	Gets the name of the object as C Ascii null-terminated string -for reading only!

void	SetName (const char myname[])
	Sets the name of this object, as ascii string.

std::string	GetNameString () const
	Gets the name of the object as C Ascii null-terminated string.

void	SetNameString (const std::string &myname)
	Sets the name of this object, as std::string.

void	MFlagsSetAllOFF (int &mflag)

void	MFlagsSetAllON (int &mflag)

void	MFlagSetON (int &mflag, int mask)

void	MFlagSetOFF (int &mflag, int mask)

int	MFlagGet (int &mflag, int mask)

virtual void	ArchiveOUT (ChArchiveOut &marchive)
	Method to allow serialization of transient data to archives.

virtual void	ArchiveIN (ChArchiveIn &marchive)
	Method to allow de-serialization of transient data from archives.

virtual std::string &	ArchiveContainerName ()

Protected Member Functions
virtual bool	IsStiff () override
	Inherited classes could override this and return true, if the load benefits from a jacobian when using implicit integrators.

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

Protected Attributes
ChVector	computed_abs_force

ChVector	computed_abs_torque

Protected Attributes inherited from chrono::ChLoadBase
ChLoadJacobians *	jacobians

Protected Attributes inherited from chrono::ChObj
double	ChTime
	the time of simulation for the object

Additional Inherited Members
Public Attributes inherited from chrono::ChLoadCustom
std::shared_ptr< ChLoadable >	loadable

ChVectorDynamic	load_Q

Constructor & Destructor Documentation

◆ ChLoadXYZROTnode()

chrono::fea::ChLoadXYZROTnode::ChLoadXYZROTnode ( std::shared_ptr< ChNodeFEAxyzrot > body )

Parameters

body	node to apply load to

Member Function Documentation

◆ ComputeForceTorque()

virtual void chrono::fea::ChLoadXYZROTnode::ComputeForceTorque	(	const ChFrameMoving<> &	node_frame_abs_pos_vel,
		ChVector<> &	abs_force,
		ChVector<> &	abs_torque
	)

pure virtual

Compute the force and torque on the node, in absolute coordsystem, given absolute position and speed of node passed via node_frame_abs_pos_vel.

Inherited classes MUST IMPLEMENT THIS.

Implemented in chrono::fea::ChLoadXYZROTnodeForceAbsolute.

◆ ComputeQ()

void chrono::fea::ChLoadXYZROTnode::ComputeQ	(	ChState *	state_x,
		ChStateDelta *	state_w
	)

overridevirtual

Compute Q, the generalized load.

Called automatically at each Update().

Parameters

state_x	state position to evaluate Q
state_w	state speed to evaluate Q

Implements chrono::ChLoadBase.

◆ Update()

void chrono::fea::ChLoadXYZROTnode::Update ( double time )

overrideprotectedvirtual

Update: this is called at least at each time step.

It recomputes the generalized load Q vector(s)
It recomputes the jacobian(s) K,R,M in case of stiff load Q and jacobians assumed evaluated at the current state. Jacobian structures are automatically allocated if needed.

Reimplemented from chrono::ChLoadBase.

Reimplemented in chrono::fea::ChLoadXYZROTnodeForceAbsolute.

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

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

Description

Public Member Functions

Protected Member Functions