Description

Base class for a deformable tire model.

#include <ChDeformableTire.h>

Inheritance diagram for chrono::vehicle::ChDeformableTire:
Collaboration diagram for chrono::vehicle::ChDeformableTire:

Public Types

enum  ContactSurfaceType { NODE_CLOUD, TRIANGLE_MESH }
 Type of the mesh contact surface.
 

Public Member Functions

 ChDeformableTire (const std::string &name)
 Construct a deformable tire with the specified name. More...
 
void SetContactSurfaceType (ContactSurfaceType type)
 Set the type of contact surface.
 
ContactSurfaceType GetContactSurfaceType () const
 
void SetContactNodeRadius (double radius)
 Set radius of contact nodes. More...
 
double GetContactNodeRadius () const
 
void SetContactFaceThickness (double thickness)
 Set thickness of contact faces (radius of swept sphere). More...
 
double GetContactFaceThickness () const
 
void SetContactFrictionCoefficient (float friction_coefficient)
 Set coefficient of friction. More...
 
void SetContactRestitutionCoefficient (float restitution_coefficient)
 Set coefficient of restiturion. More...
 
void SetContactMaterialProperties (float young_modulus, float poisson_ratio)
 Set contact material properties. More...
 
void SetContactMaterialCoefficients (float kn, float gn, float kt, float gt)
 Set contact material coefficients. More...
 
float GetCoefficientFriction () const
 Get coefficient of friction for contact material.
 
float GetCoefficientRestitution () const
 Get coefficient of restitution for contact material.
 
float GetYoungModulus () const
 Get Young's modulus of elasticity for contact material.
 
float GetPoissonRatio () const
 Get Poisson ratio for contact material.
 
float GetKn () const
 Get normal stiffness coefficient for contact material.
 
float GetKt () const
 Get tangential stiffness coefficient for contact material.
 
float GetGn () const
 Get normal viscous damping coefficient for contact material.
 
float GetGt () const
 Get tangential viscous damping coefficient for contact material.
 
std::shared_ptr
< ChMaterialSurfaceSMC
GetContactMaterial () const
 Get the tire contact material. More...
 
void EnablePressure (bool val)
 Enable/disable tire pressure (default: true).
 
bool IsPressureEnabled () const
 
void EnableContact (bool val)
 Enable/disable tire contact (default: true).
 
bool IsContactEnabled () const
 
void EnableRimConnection (bool val)
 Enable/disable tire-rim connection (default: true).
 
bool IsRimConnectionEnabled () const
 
fea::ChVisualizationFEAmesh *const GetMeshVisualization () const
 Get a handle to the mesh visualization.
 
std::shared_ptr< fea::ChMeshGetMesh () const
 Get the underlying FEA mesh.
 
std::shared_ptr
< fea::ChContactSurface
GetContactSurface () const
 Get the mesh contact surface. More...
 
std::shared_ptr< ChLoadContainerGetLoadContainer () const
 Get the load container associated with this tire.
 
void SetPressure (double pressure)
 Set the tire pressure.
 
virtual double GetRimRadius () const =0
 Get the rim radius (inner tire radius).
 
virtual double GetWidth () const =0
 Get the tire width.
 
double GetMass () const
 Get total tire mass.
 
virtual TireForce GetTireForce (bool cosim=false) const override
 Get the tire force and moment. More...
 
virtual void Initialize (std::shared_ptr< ChBody > wheel, VehicleSide side) override
 Initialize this tire system. More...
 
virtual void AddVisualizationAssets (VisualizationType vis) overridefinal
 Add visualization assets for the rigid tire subsystem.
 
virtual void RemoveVisualizationAssets () overridefinal
 Remove visualization assets for the rigid tire subsystem.
 
- Public Member Functions inherited from chrono::vehicle::ChTire
 ChTire (const std::string &name)
 
virtual void Synchronize (double time, const WheelState &wheel_state, const ChTerrain &terrain)
 Update the state of this tire system at the current time. More...
 
virtual void Advance (double step)
 Advance the state of this tire by the specified time step.
 
virtual double GetRadius () const =0
 Get the tire radius.
 
virtual double GetSlipAngle () const
 Get the tire slip angle. More...
 
virtual double GetLongitudinalSlip () const
 Get the tire longitudinal slip. More...
 
virtual double GetCamberAngle () const
 Get the tire camber angle. More...
 
- Public Member Functions inherited from chrono::vehicle::ChPart
 ChPart (const std::string &name)
 Construct a vehicle subsystem with the specified name. More...
 
const std::string & GetName () const
 Get the name identifier for this track shoe subsystem.
 
void SetName (const std::string &name)
 Set the name identifier for this track shoe subsystem.
 
void SetVisualizationType (VisualizationType vis)
 Set the visualization mode for this subsystem.
 
void SetContactFrictionCoefficient (float friction_coefficient)
 Set coefficient of friction. More...
 
void SetContactRestitutionCoefficient (float restitution_coefficient)
 Set coefficient of restitution. More...
 
void SetContactMaterialProperties (float young_modulus, float poisson_ratio)
 Set contact material properties. More...
 
void SetContactMaterialCoefficients (float kn, float gn, float kt, float gt)
 Set contact material coefficients. More...
 
float GetCoefficientFriction () const
 Get coefficient of friction for contact material.
 
float GetCoefficientRestitution () const
 Get coefficient of restitution for contact material.
 
float GetYoungModulus () const
 Get Young's modulus of elasticity for contact material.
 
float GetPoissonRatio () const
 Get Poisson ratio for contact material.
 
float GetKn () const
 Get normal stiffness coefficient for contact material.
 
float GetKt () const
 Get tangential stiffness coefficient for contact material.
 
float GetGn () const
 Get normal viscous damping coefficient for contact material.
 
float GetGt () const
 Get tangential viscous damping coefficient for contact material.
 

Protected Member Functions

virtual double GetDefaultPressure () const =0
 Return the default tire pressure.
 
virtual std::vector
< std::shared_ptr
< fea::ChNodeFEAbase > > 
GetConnectedNodes () const =0
 Return list of nodes connected to the rim.
 
virtual void CreateMesh (const ChFrameMoving<> &wheel_frame, VehicleSide side)=0
 Create the FEA nodes and elements. More...
 
virtual void CreatePressureLoad ()=0
 Create the ChLoad for applying pressure to the tire. More...
 
virtual void CreateContactSurface ()=0
 Create the contact surface for the tire mesh. More...
 
virtual void CreateRimConnections (std::shared_ptr< ChBody > wheel)=0
 Create the tire-rim connections. More...
 

Protected Attributes

std::shared_ptr< fea::ChMeshm_mesh
 tire mesh
 
std::shared_ptr< ChLoadContainerm_load_container
 load container (for pressure load)
 
std::vector< std::shared_ptr
< fea::ChLinkPointFrame > > 
m_connections
 tire-wheel point connections
 
std::vector< std::shared_ptr
< fea::ChLinkDirFrame > > 
m_connectionsD
 tire-wheel direction connections
 
std::vector< std::shared_ptr
< ChLinkMateFix > > 
m_connectionsF
 tire-wheel fix connection (point+rotation)
 
bool m_connection_enabled
 enable tire connections to rim
 
bool m_pressure_enabled
 enable internal tire pressure
 
bool m_contact_enabled
 enable tire-terrain contact
 
double m_pressure
 internal tire pressure
 
ContactSurfaceType m_contact_type
 type of contact surface model (node cloud or mesh)
 
double m_contact_node_radius
 node radius (for node cloud contact surface)
 
double m_contact_face_thickness
 face thickness (for mesh contact surface)
 
float m_friction
 contact coefficient of friction
 
float m_restitution
 contact coefficient of restitution
 
float m_young_modulus
 contact material Young modulus
 
float m_poisson_ratio
 contact material Poisson ratio
 
float m_kn
 normal contact stiffness
 
float m_gn
 normal contact damping
 
float m_kt
 tangential contact stiffness
 
float m_gt
 tangential contact damping
 
std::shared_ptr
< ChMaterialSurfaceSMC
m_contact_mat
 tire contact material
 
std::shared_ptr
< fea::ChVisualizationFEAmesh
m_visualization
 tire mesh visualization
 
- Protected Attributes inherited from chrono::vehicle::ChTire
VehicleSide m_side
 tire mounted on left/right side
 
std::shared_ptr< ChBodym_wheel
 associated wheel body
 
- Protected Attributes inherited from chrono::vehicle::ChPart
std::string m_name
 
float m_friction
 contact coefficient of friction
 
float m_restitution
 contact coefficient of restitution
 
float m_young_modulus
 contact material Young modulus
 
float m_poisson_ratio
 contact material Poisson ratio
 
float m_kn
 normal contact stiffness
 
float m_gn
 normal contact damping
 
float m_kt
 tangential contact stiffness
 
float m_gt
 tangential contact damping
 

Additional Inherited Members

- Static Public Member Functions inherited from chrono::vehicle::ChPart
static ChMatrix33 TransformInertiaMatrix (const ChVector<> &moments, const ChVector<> &products, const ChMatrix33<> &vehicle_rot, const ChMatrix33<> &body_rot)
 Utility function for transforming inertia tensors between centroidal frames. More...
 
- Static Protected Member Functions inherited from chrono::vehicle::ChTire
static bool disc_terrain_contact (const ChTerrain &terrain, const ChVector<> &disc_center, const ChVector<> &disc_normal, double disc_radius, ChCoordsys<> &contact, double &depth)
 Perform disc-terrain collision detection. More...
 

Constructor & Destructor Documentation

chrono::vehicle::ChDeformableTire::ChDeformableTire ( const std::string &  name)

Construct a deformable tire with the specified name.

Parameters
[in]namename of this tire system

Member Function Documentation

virtual void chrono::vehicle::ChDeformableTire::CreateContactSurface ( )
protectedpure virtual

Create the contact surface for the tire mesh.

A derived class must create a contact surface and add it to the underlying mesh.

Implemented in chrono::vehicle::ChFEATire, chrono::vehicle::ChReissnerTire, and chrono::vehicle::ChANCFTire.

virtual void chrono::vehicle::ChDeformableTire::CreateMesh ( const ChFrameMoving<> &  wheel_frame,
VehicleSide  side 
)
protectedpure virtual

Create the FEA nodes and elements.

The wheel rotational axis is assumed to be the Y axis.

Parameters
[in]wheel_frameframe of associated wheel
[in]sideleft/right vehicle side

Implemented in chrono::vehicle::FEATire, chrono::vehicle::ANCFTire, and chrono::vehicle::ReissnerTire.

virtual void chrono::vehicle::ChDeformableTire::CreatePressureLoad ( )
protectedpure virtual

Create the ChLoad for applying pressure to the tire.

A derived class must create a load and add it to the underlying load container.

Implemented in chrono::vehicle::ChFEATire, chrono::vehicle::ChReissnerTire, and chrono::vehicle::ChANCFTire.

virtual void chrono::vehicle::ChDeformableTire::CreateRimConnections ( std::shared_ptr< ChBody wheel)
protectedpure virtual

Create the tire-rim connections.

A derived class must create the various constraints between the tire and the provided wheel body and add them to the underlying system.

Parameters
[in]wheelassociated wheel body

Implemented in chrono::vehicle::ChFEATire, chrono::vehicle::ChReissnerTire, and chrono::vehicle::ChANCFTire.

std::shared_ptr<ChMaterialSurfaceSMC> chrono::vehicle::ChDeformableTire::GetContactMaterial ( ) const

Get the tire contact material.

Note that this is not set until after tire initialization.

std::shared_ptr< ChContactSurface > chrono::vehicle::ChDeformableTire::GetContactSurface ( ) const

Get the mesh contact surface.

If contact is not enabled, an empty shared pointer is returned.

TireForce chrono::vehicle::ChDeformableTire::GetTireForce ( bool  cosim = false) const
overridevirtual

Get the tire force and moment.

A ChDeformableTire always returns zero forces and moments if the tire is simulated together with the associated vehicle (the tire forces are implicitly applied to the associated wheel through the tire-wheel connections). If the tire is co-simulated, the tire force and moment encapsulate the tire-terrain forces as well as the weight of the tire itself.

Parameters
[in]cosimindicate if the tire is co-simulated

Implements chrono::vehicle::ChTire.

void chrono::vehicle::ChDeformableTire::Initialize ( std::shared_ptr< ChBody wheel,
VehicleSide  side 
)
overridevirtual

Initialize this tire system.

This function creates the tire contact shape and attaches it to the associated wheel body.

Parameters
[in]wheelassociated wheel body
[in]sideleft/right vehicle side

Reimplemented from chrono::vehicle::ChTire.

void chrono::vehicle::ChDeformableTire::SetContactFaceThickness ( double  thickness)

Set thickness of contact faces (radius of swept sphere).

This value is relevant only for TRIANGLE_MESH contact surface type.

void chrono::vehicle::ChDeformableTire::SetContactFrictionCoefficient ( float  friction_coefficient)

Set coefficient of friction.

The default value is 0.6

void chrono::vehicle::ChDeformableTire::SetContactMaterialCoefficients ( float  kn,
float  gn,
float  kt,
float  gt 
)

Set contact material coefficients.

These values are used directly to compute contact forces (if the containing system is so configured and if the SMC contact method is being used). The default values are: kn=2e5, gn=40, kt=2e5, gt=20

Parameters
[in]knnormal contact stiffness
[in]gnnormal contact damping
[in]kttangential contact stiffness
[in]gttangential contact damping
void chrono::vehicle::ChDeformableTire::SetContactMaterialProperties ( float  young_modulus,
float  poisson_ratio 
)

Set contact material properties.

These values are used to calculate contact material coefficients (if the containing system is so configured and if the SMC contact method is being used). The default values are: Y = 2e5 and nu = 0.3

Parameters
[in]young_modulusYoung's modulus of elasticity
[in]poisson_ratioPoisson ratio
void chrono::vehicle::ChDeformableTire::SetContactNodeRadius ( double  radius)

Set radius of contact nodes.

This value is relevant only for NODE_CLOUD contact surface type.

void chrono::vehicle::ChDeformableTire::SetContactRestitutionCoefficient ( float  restitution_coefficient)

Set coefficient of restiturion.

The default value is 0.1