Description

Interface for objects that generate contacts.

One should inherit from ChContactable_1vars, ChContactable_2vars etc. depending on the number of ChVariable objects contained in the object (i.e. the variable chunks to whom the contact point position depends, also the variables affected by contact force).

#include <ChContactable.h>

Inherited by chrono::ChContactable_1vars< 3 >, chrono::ChContactable_1vars< 6 >, chrono::ChContactable_3vars< 3, 3, 3 >, chrono::ChContactable_3vars< 6, 6, 6 >, chrono::ChContactable_1vars< T1 >, chrono::ChContactable_2vars< T1, T2 >, and chrono::ChContactable_3vars< T1, T2, T3 >.

Public Types
enum	eChContactableType { CONTACTABLE_UNKNOWN = 0, CONTACTABLE_6, CONTACTABLE_3, CONTACTABLE_333, CONTACTABLE_666 }
	Enum used for dispatcher optimization instead than rtti. More...

Public Member Functions
void	AddCollisionModel (std::shared_ptr< ChCollisionModel > model)
	Add the collision model.

void	AddCollisionShape (std::shared_ptr< ChCollisionShape > shape, const ChFrame<> &frame=ChFrame<>())
	Add a collision shape. More...

std::shared_ptr< ChCollisionModel >	GetCollisionModel () const
	Access the collision model.

virtual bool	IsContactActive ()=0
	Indicate whether or not the object must be considered in collision detection.

virtual int	GetContactableNumCoordsPosLevel ()=0
	Get the number of DOFs affected by this object (position part).

virtual int	GetContactableNumCoordsVelLevel ()=0
	Get the number of DOFs affected by this object (speed part).

virtual void	ContactableGetStateBlockPosLevel (ChState &x)=0
	Get all the DOFs packed in a single vector (position part).

virtual void	ContactableGetStateBlockVelLevel (ChStateDelta &w)=0
	Get all the DOFs packed in a single vector (speed part).

virtual void	ContactableIncrementState (const ChState &x, const ChStateDelta &dw, ChState &x_new)=0
	Increment the provided state of this object by the given state-delta increment. More...

virtual ChVector3d	GetContactPoint (const ChVector3d &loc_point, const ChState &state_x)=0
	Express the local point in absolute frame, for the given state position.

virtual ChVector3d	GetContactPointSpeed (const ChVector3d &loc_point, const ChState &state_x, const ChStateDelta &state_w)=0
	Get the absolute speed of a local point attached to the contactable. More...

virtual ChVector3d	GetContactPointSpeed (const ChVector3d &abs_point)=0
	Get the absolute speed of point abs_point if attached to the surface.

virtual ChFrame	GetCollisionModelFrame ()=0
	Return the frame of the associated collision model relative to the contactable object. More...

virtual void	ContactForceLoadResidual_F (const ChVector3d &F, const ChVector3d &T, const ChVector3d &abs_point, ChVectorDynamic<> &R)=0
	Apply the given force & torque at the given location and load into the global generalized force vector. More...

virtual void	ContactComputeQ (const ChVector3d &F, const ChVector3d &T, const ChVector3d &point, const ChState &state_x, ChVectorDynamic<> &Q, int offset)=0
	Compute a contiguous vector of generalized forces Q from a given force & torque at the given point. More...

virtual double	GetContactableMass ()=0
	This can be useful in some SMC code:

virtual ChPhysicsItem *	GetPhysicsItem ()=0
	This is only for backward compatibility. More...

virtual eChContactableType	GetContactableType () const =0
	This must return the proper eChContactableType enum, for allowing a faster collision dispatcher in ChContactContainer classes (this enum will be used instead of slow dynamic_cast<> to infer the type of ChContactable, if possible)

void	SetUserData (const std::shared_ptr< void > &data)
	Set user-data associated with this contactable.

bool	HasData () const
	Check if this contactable has associated user-data.

template<typename T >
std::shared_ptr< T >	GetUserData () const
	Get the user-data using static cast to a known type.

void	ArchiveOut (ChArchiveOut &archive_out)
	Method to allow serialization of transient data to archives.

void	ArchiveIn (ChArchiveIn &archive_in)
	Method to allow deserialization of transient data from archives.

Protected Attributes
std::shared_ptr< ChCollisionModel >	collision_model

Member Enumeration Documentation

◆ eChContactableType

enum chrono::ChContactable::eChContactableType

Enum used for dispatcher optimization instead than rtti.

Enumerator
CONTACTABLE_UNKNOWN	unknown contactable type
CONTACTABLE_6	1 variable with 6 DOFs (e.g., ChBody, ChNodeFEAxyzrot)
CONTACTABLE_3	1 variable with 3 DOFS (e.g., ChNodeFEAxyz, ChParticle)
CONTACTABLE_333	3 variables, each with 3 DOFs (e.g., triangle between 3 ChNodeFEAxyz nodes)
CONTACTABLE_666	3 variables, each with 6 DOFs (e.g., triangle between 3 ChNodeFEAxyzrot nodes)

Member Function Documentation

◆ AddCollisionShape()

void chrono::ChContactable::AddCollisionShape	(	std::shared_ptr< ChCollisionShape >	shape,
		const ChFrame<> &	frame = `ChFrame<>()`
	)

Add a collision shape.

If this item does not have a collision model, one is created.

◆ ContactableIncrementState()

virtual void chrono::ChContactable::ContactableIncrementState	(	const ChState &	x,
		const ChStateDelta &	dw,
		ChState &	x_new
	)

pure virtual

Increment the provided state of this object by the given state-delta increment.

Compute: x_new = x + dw.

Implemented in chrono::fea::ChContactTriangleXYZRot, chrono::fea::ChContactNodeXYZRot, chrono::fea::ChContactTriangleXYZ, chrono::ChParticle, and chrono::fea::ChContactNodeXYZ.

◆ ContactComputeQ()

virtual void chrono::ChContactable::ContactComputeQ	(	const ChVector3d &	F,
		const ChVector3d &	T,
		const ChVector3d &	point,
		const ChState &	state_x,
		ChVectorDynamic<> &	Q,
		int	offset
	)

pure virtual

Compute a contiguous vector of generalized forces Q from a given force & torque at the given point.

Used for computing stiffness matrix (square force jacobian) by backward differentiation. The force F and its application point are specified in the global frame. The torque T is specified in the global frame too. Each object must set the entries in Q corresponding to its variables, starting at the specified offset. If needed, the object states must be extracted from the provided state position.

Parameters

F	force
T	torque
point	application point
state_x	global state vector
Q	generalized force vector
offset	index offset

Implemented in chrono::fea::ChContactTriangleXYZRot, chrono::fea::ChContactNodeXYZRot, chrono::fea::ChContactTriangleXYZ, chrono::ChParticle, and chrono::fea::ChContactNodeXYZ.

◆ ContactForceLoadResidual_F()

virtual void chrono::ChContactable::ContactForceLoadResidual_F	(	const ChVector3d &	F,
		const ChVector3d &	T,
		const ChVector3d &	abs_point,
		ChVectorDynamic<> &	R
	)

pure virtual

Apply the given force & torque at the given location and load into the global generalized force vector.

The force F and its application point are specified in the absolute reference frame. The torque T is specified in the global frame too. Each object must update the entries in R corresponding to its variables. Force for example could come from a penalty model.

Parameters

F	force
T	torque
abs_point	application point
R	global generalized force vector

Implemented in chrono::fea::ChContactTriangleXYZRot, chrono::fea::ChContactNodeXYZRot, chrono::fea::ChContactTriangleXYZ, chrono::ChParticle, and chrono::fea::ChContactNodeXYZ.

◆ GetCollisionModelFrame()

virtual ChFrame chrono::ChContactable::GetCollisionModelFrame ( )

pure virtual

Return the frame of the associated collision model relative to the contactable object.

ChCollisionModel might call this to get the position of the contact model (when rigid) and sync it.

Implemented in chrono::fea::ChContactTriangleXYZRot, chrono::fea::ChContactNodeXYZRot, chrono::fea::ChContactTriangleXYZ, chrono::ChParticle, and chrono::fea::ChContactNodeXYZ.

◆ GetContactPointSpeed()

virtual ChVector3d chrono::ChContactable::GetContactPointSpeed	(	const ChVector3d &	loc_point,
		const ChState &	state_x,
		const ChStateDelta &	state_w
	)

pure virtual

Get the absolute speed of a local point attached to the contactable.

The given point is assumed to be expressed in the local frame of this object. This function must use the provided states.

Implemented in chrono::fea::ChContactTriangleXYZRot, chrono::fea::ChContactNodeXYZRot, chrono::fea::ChContactTriangleXYZ, chrono::fea::ChContactNodeXYZ, and chrono::ChParticle.

◆ GetPhysicsItem()

virtual ChPhysicsItem* chrono::ChContactable::GetPhysicsItem ( )

pure virtual

This is only for backward compatibility.

Note that in recent code the reference to the ChPhysicsItem should disappear. The ChPhysicsItem could be the ChContactable itself (ex. see the ChBody) or a container (ex. the ChMEsh, for ChContactTriangle)

Implemented in chrono::ChBody, chrono::fea::ChContactTriangleXYZRot, chrono::fea::ChContactNodeXYZRot, chrono::fea::ChContactTriangleXYZ, chrono::ChParticle, and chrono::fea::ChContactNodeXYZ.

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

/builds/uwsbel/chrono/src/chrono/physics/ChContactable.h
/builds/uwsbel/chrono/src/chrono/physics/ChContactable.cpp

Description

Public Types

Public Member Functions

Protected Attributes

Member Enumeration Documentation

◆ eChContactableType

Member Function Documentation

◆ AddCollisionShape()

◆ ContactableIncrementState()

◆ ContactComputeQ()

◆ ContactForceLoadResidual_F()

◆ GetCollisionModelFrame()

◆ GetContactPointSpeed()

◆ GetPhysicsItem()