chrono::ChLoadNodeXYZForce Class Referenceabstract


Base class for loads representing a concentrated force acting on a ChNodeXYZ.

Users should inherit from this and implement custom ComputeForce(). Note: there are already some predefined examples, ie. children classes with common concrete implementations, such as ChLoadNodeXYZForceAbs ; take inspiration from those example to inherit your own load if they are not enough.

#include <ChLoadsNodeXYZ.h>

Inheritance diagram for chrono::ChLoadNodeXYZForce:
Collaboration diagram for chrono::ChLoadNodeXYZForce:

Public Member Functions

 ChLoadNodeXYZForce (std::shared_ptr< ChNodeXYZ > node)
virtual void ComputeForce (const ChVector3d &abs_pos, const ChVector3d &abs_vel, ChVector3d &abs_force)=0
 Compute the force on the node, in absolute coordsystem, given position of node as abs_pos.
virtual void ComputeQ (ChState *state_x, ChStateDelta *state_w) override
 Compute Q, the generalized load. More...
ChVector3d GetForce () const
 Return the last computed value of the applied force. More...
- Public Member Functions inherited from chrono::ChLoadCustom
 ChLoadCustom (std::shared_ptr< ChLoadable > loadable_object)
virtual int LoadGetNumCoordsPosLevel () override
 Gets the number of DOFs affected by this load (position part).
virtual int LoadGetNumCoordsVelLevel () 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 (e.g., as obtained by LoadGetStateBlock_x()) by a given packed state-delta. More...
virtual int LoadGetNumFieldCoords () override
 Number of coordinates in the interpolated field. More...
virtual void ComputeJacobian (ChState *state_x, ChStateDelta *state_w) override
 Compute Jacobian matrices K=-dQ/dx, R=-dQ/dv, and M=-dQ/da. More...
virtual void LoadIntLoadResidual_F (ChVectorDynamic<> &R, double c) override
 Add the internal loads Q (pasted at global offsets) into a global vector R, multiplied by a scaling factor c. More...
virtual void LoadIntLoadResidual_Mv (ChVectorDynamic<> &R, const ChVectorDynamic<> &w, double c) override
 Increment a vector R with the matrix-vector product M*w, scaled by the factor c. More...
virtual void LoadIntLoadLumpedMass_Md (ChVectorDynamic<> &Md, double &err, const double c) override
 Add the lumped mass to an Md vector, representing a mass diagonal matrix. More...
virtual void CreateJacobianMatrices () override
 Create the Jacobian loads if needed and set the ChVariables referenced by the sparse KRM block.
virtual ChVectorDynamicGetQ ()
 Access the generalized load vector Q.
- Public Member Functions inherited from chrono::ChLoadBase
ChLoadJacobiansGetJacobians ()
 Access the Jacobians (if any, i.e. if this is a stiff load).
virtual void InjectKRMMatrices (ChSystemDescriptor &descriptor)
 Register with the given system descriptor any ChKRMBlock objects associated with this item.
virtual void LoadKRMMatrices (double Kfactor, double Rfactor, double Mfactor)
 Compute and load current stiffnes (K), damping (R), and mass (M) matrices in encapsulated ChKRMBlock objects. More...
- Public Member Functions inherited from chrono::ChObj
 ChObj (const ChObj &other)
virtual ChObjClone () const =0
 "Virtual" copy constructor.
int GetIdentifier () const
 Get the unique integer identifier of this object. More...
void SetTag (int tag)
 Set an object integer tag (default: -1). More...
int GetTag () const
 Get the tag of this object.
void SetName (const std::string &myname)
 Set the name of this object.
const std::string & GetName () const
 Get the name of this object.
double GetChTime () const
 Gets the simulation time of this object.
void SetChTime (double m_time)
 Sets the simulation time of this object.
virtual void ArchiveOut (ChArchiveOut &archive_out)
 Method to allow serialization of transient data to archives.
virtual void ArchiveIn (ChArchiveIn &archive_in)
 Method to allow de-serialization of transient data from archives.
virtual std::string & ArchiveContainerName ()

Protected Member Functions

virtual bool IsStiff () override
 Report if this is load is stiff. More...
virtual void Update (double time) override
 Update, called at least at each time step. More...
- Protected Member Functions inherited from chrono::ChObj
int GenerateUniqueIdentifier ()

Protected Attributes

ChVector3d computed_abs_force
- Protected Attributes inherited from chrono::ChLoadBase
- Protected Attributes inherited from chrono::ChObj
double ChTime
 object simulation time
std::string m_name
 object name
int m_identifier
 object unique identifier
int m_tag
 user-supplied tag

Additional Inherited Members

- Public Attributes inherited from chrono::ChLoadCustom
std::shared_ptr< ChLoadableloadable
ChVectorDynamic load_Q

Member Function Documentation

◆ ComputeQ()

void chrono::ChLoadNodeXYZForce::ComputeQ ( ChState state_x,
ChStateDelta state_w 

Compute Q, the generalized load.

Called automatically at each Update().

state_xstate position to evaluate Q
state_wstate speed to evaluate Q

Implements chrono::ChLoadBase.

◆ GetForce()

ChVector3d chrono::ChLoadNodeXYZForce::GetForce ( ) const

Return the last computed value of the applied force.

Used primarily for diagnostics, this function returns the force on the node expressed in absolute coordinates.

◆ IsStiff()

virtual bool chrono::ChLoadNodeXYZForce::IsStiff ( )

Report if this is load is stiff.

If so, InjectKRMMatrices will provide the Jacobians of the load.

Implements chrono::ChLoadBase.

Reimplemented in chrono::ChLoadNodeXYZForceAbs.

◆ Update()

void chrono::ChLoadNodeXYZForce::Update ( double  time)

Update, called at least at each time step.

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

Reimplemented from chrono::ChLoadBase.

Reimplemented in chrono::ChLoadNodeXYZForceAbs.

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