Description

Interface to a Chrono::Gpu system.

#include <ChSystemGpu.h>

Inheritance diagram for chrono::gpu::ChSystemGpu:

Public Member Functions
	ChSystemGpu (float sphere_rad, float density, const ChVector< float > &boxDims, ChVector< float > O=ChVector< float >(0))
	Construct system with given sphere radius, density, big domain dimensions and center.

	ChSystemGpu (const std::string &checkpoint)
	Construct system with a checkpoint file.

void	SetGravitationalAcceleration (const ChVector< float > &g)
	Set gravitational acceleration vector.

void	SetParticles (const std::vector< ChVector< float >> &points, const std::vector< ChVector< float >> &vels=std::vector< ChVector< float >>(), const std::vector< ChVector< float >> &ang_vels=std::vector< ChVector< float >>())
	Set particle positions, velocities and angular velocities.

void	ReadParticleFile (const std::string &infilename)
	Set particle positions, velocities and angular velocities from a file.

void	ReadContactHistoryFile (const std::string &infilename)
	Set particle contact friction history from a file.

void	ReadCheckpointFile (const std::string &infilename, bool overwrite=false)

void	SetBDFixed (bool fixed)
	Set the big domain to be fixed or not. More...

void	SetBDCenter (const ChVector< float > &O)
	Set the center of the big box domain, relative to the origin of the coordinate system (default: [0,0,0]). More...

void	SetParticleFixed (const std::vector< bool > &fixed)
	Set flags indicating whether or not a particle is fixed. More...

void	SetParticleOutputMode (CHGPU_OUTPUT_MODE mode)
	Set the output mode of the simulation.

void	SetParticleOutputFlags (unsigned int flags)
	Set output settings bit flags by bitwise ORing settings in CHGPU_OUTPUT_FLAGS.

void	SetFixedStepSize (float size_UU)
	Set timestep size.

void	SetDefragmentOnInitialize (bool defragment)
	If yes, on Initialize(), particles will have their order re-arranged so that those in the same SD are close together. More...

void	EnableMinLength (bool useMinLen)
	Ensure that the deformation-based length unit is used.

void	DisableMinLength ()

void	SetTimeIntegrator (CHGPU_TIME_INTEGRATOR new_integrator)
	Set the time integration scheme for the system.

void	SetFrictionMode (CHGPU_FRICTION_MODE new_mode)
	Set friction formulation. More...

void	SetRollingMode (CHGPU_ROLLING_MODE new_mode)
	Set rolling resistence formulation. More...

void	SetStaticFrictionCoeff_SPH2SPH (float mu)
	Set sphere-to-sphere static friction coefficient.

void	SetStaticFrictionCoeff_SPH2WALL (float mu)
	Set sphere-to-wall static friction coefficient.

void	SetRollingCoeff_SPH2SPH (float mu)
	Set sphere-to-sphere rolling friction coefficient – units and use vary by rolling friction mode.

void	SetRollingCoeff_SPH2WALL (float mu)
	Set sphere-to-wall rolling friction coefficient – units and use vary by rolling friction mode.

void	SetSpinningCoeff_SPH2SPH (float mu)
	Set sphere-to-sphere spinning friction coefficient – units and use vary by spinning friction mode.

void	SetSpinningCoeff_SPH2WALL (float mu)
	Set sphere-to-wall spinning friction coefficient – units and use vary by spinning friction mode.

void	SetKn_SPH2SPH (double someValue)
	Set sphere-to-sphere normal contact stiffness.

void	SetKn_SPH2WALL (double someValue)
	Set sphere-to-wall normal contact stiffness.

void	SetGn_SPH2SPH (double someValue)
	Set sphere-to-sphere normal damping coefficient.

void	SetGn_SPH2WALL (double someValue)
	Set sphere-to-wall normal damping coefficient.

void	SetKt_SPH2SPH (double someValue)
	Set sphere-to-sphere tangential contact stiffness.

void	SetGt_SPH2SPH (double someValue)
	Set sphere-to-sphere tangential damping coefficient.

void	SetKt_SPH2WALL (double someValue)
	Set sphere-to-wall tangential contact stiffness.

void	SetGt_SPH2WALL (double someValue)
	Set sphere-to-wall tangential damping coefficient.

void	SetCohesionRatio (float someValue)
	Set the ratio of cohesion to gravity for monodisperse spheres. Assumes a constant cohesion model.

void	SetAdhesionRatio_SPH2WALL (float someValue)
	Set the ratio of adhesion to gravity for sphere to wall. Assumes a constant cohesion model.

void	UseMaterialBasedModel (bool val)

void	SetYoungModulus_SPH (double someValue)
	Set youngs modulus of spheres.

void	SetYoungModulus_WALL (double someValue)
	Set youngs modulus of boundary.

void	SetPoissonRatio_SPH (double someValue)
	Set poisson ratio of sphere.

void	SetPoissonRatio_WALL (double someValue)
	Set poisson ratio of boundary.

void	SetRestitution_SPH (double someValue)
	Set coefficient of restitution of spheres.

void	SetRestitution_WALL (double someValue)
	Set coefficient of restitution of spheres.

void	SetMaxSafeVelocity_SU (float max_vel)
	Safety check velocity to ensure the simulation is still stable.

void	SetPsiFactors (unsigned int psi_T, unsigned int psi_L, float psi_R=1.f)
	Set tuning psi factors for tuning the non-dimensionalization.

void	SetPsiT (unsigned int psi_T)

void	SetPsiL (unsigned int psi_L)

void	SetPsiR (float psi_R=1.f)

void	SetRecordingContactInfo (bool record)
	Enable/disable recording of contact info.

void	SetSimTime (float time)
	Manually set the simulation time (mainly used for restarted simulation).

void	SetVerbosity (CHGPU_VERBOSITY level)
	Set simualtion verbosity level.

size_t	CreateBCSphere (const ChVector< float > &center, float radius, bool outward_normal, bool track_forces, float mass)
	Create an axis-aligned sphere boundary condition.

size_t	CreateBCConeZ (const ChVector< float > &tip, float slope, float hmax, float hmin, bool outward_normal, bool track_forces)
	Create a Z-axis aligned cone boundary condition.

size_t	CreateBCPlane (const ChVector< float > &pos, const ChVector< float > &normal, bool track_forces)
	Create a plane boundary condition.

size_t	CreateCustomizedPlate (const ChVector< float > &pos_center, const ChVector< float > &normal, float hdim_y)
	create a plate boundary condition

size_t	CreateBCCylinderZ (const ChVector< float > &center, float radius, bool outward_normal, bool track_forces)
	Create a Z-axis aligned cylinder boundary condition.

bool	DisableBCbyID (size_t BC_id)
	Disable a boundary condition by its ID, returns false if the BC does not exist.

bool	EnableBCbyID (size_t BC_id)
	Enable a boundary condition by its ID, returns false if the BC does not exist.

bool	SetBCOffsetFunction (size_t BC_id, const GranPositionFunction &offset_function)
	Enable a boundary condition by its ID, returns false if the BC does not exist.

void	setBDWallsMotionFunction (const GranPositionFunction &pos_fn)
	Prescribe the motion of the big domain, allows wavetank-style simulations.

float	GetSimTime () const
	Return current simulation time.

size_t	GetNumParticles () const
	Return the total number of particles in the system.

double	GetMaxParticleZ () const
	Return the maximum Z position over all particles.

double	GetMinParticleZ () const
	Return the minimum Z position over all particles.

unsigned int	GetNumParticleAboveZ (float ZValue) const
	Return the number of particles that are higher than a given Z coordinate.

unsigned int	GetNumParticleAboveX (float XValue) const
	Return the number of particles that are higher than a given X coordinate.

float	GetParticleRadius () const
	Return the radius of a spherical particle.

ChVector< float >	GetParticlePosition (int nSphere) const
	Return particle position.

void	SetParticlePosition (int nSphere, const ChVector< double > pos)
	Set particle position.

void	SetParticleDensity (float density)
	Set particle density.

void	SetParticleRadius (float rad)
	Set particle radius.

void	SetParticleVelocity (int nSphere, const ChVector< double > velo)
	Set particle velocity.

ChVector< float >	GetParticleAngVelocity (int nSphere) const
	Return particle angular velocity.

ChVector< float >	GetParticleLinAcc (int nSphere) const
	return particle acc

bool	IsFixed (int nSphere) const
	Return whether or not the particle is fixed.

ChVector< float >	GetParticleVelocity (int nSphere) const
	Return particle linear velocity.

float	GetParticlesKineticEnergy () const
	Return the total kinetic energy of all particles.

ChVector< float >	GetBCPlanePosition (size_t plane_id) const
	Return position of BC plane.

ChVector< float >	GetBCSpherePosition (size_t sphere_id) const
	Return position of BC sphere.

void	SetBCSpherePosition (size_t sphere_bc_id, const ChVector< float > &pos)
	Set position of BC spheres.

ChVector< float >	GetBCSphereVelocity (size_t sphere_id) const
	Return velocity of BC sphere.

void	SetBCSphereVelocity (size_t sphere_bc_id, const ChVector< float > &velo)
	Set velocity of BC spheres.

void	SetBCPlaneRotation (size_t plane_id, ChVector< double > center, ChVector< double > omega)
	Set BC plane rotation.

bool	GetBCReactionForces (size_t BC_id, ChVector< float > &force) const
	Get the reaction forces on a boundary by ID, returns false if the forces are invalid (bad BC ID)

int	GetNumContacts () const
	Return number of particle-particle contacts.

unsigned int	GetNumSDs () const
	Return number of subdomains in the big domain.

virtual void	Initialize ()
	Initialize simulation so that it can be advanced. More...

virtual double	AdvanceSimulation (float duration)
	Advance simulation by duration in user units, return actual duration elapsed. More...

void	WriteCheckpointFile (const std::string &outfilename)
	Write a one-stop checkpoint file for Chrono::Gpu. More...

void	WriteParticleFile (const std::string &outfilename) const
	Write particle positions according to the system output mode.

void	WriteContactHistoryFile (const std::string &outfilename) const
	Write contact pair history to a file.

void	WriteContactInfoFile (const std::string &outfilename) const
	Write contact force and torque to a file.

size_t	EstimateMemUsage () const
	Roughly estimate of the total amount of memory used by the system.

ChVector< float >	getRollingFrictionTorque (unsigned int i, unsigned int j)
	Get rolling friction torque between body i and j, return 0 if not in contact.

ChVector< float >	getSlidingFrictionForce (unsigned int i, unsigned int j)
	Get tangential friction force between body i and j, return 0 if not in contact.

ChVector< float >	getNormalForce (unsigned int i, unsigned int j)
	Get normal friction force between body i and j, return 0 if not in contact.

ChVector< float >	getRollingVrot (unsigned int i, unsigned int j)
	Get v_rot for rolling friction.

float	getRollingCharContactTime (unsigned int i, unsigned int j)
	get contact char time

void	getNeighbors (unsigned int ID, std::vector< unsigned int > &neighborList)
	get index list of neighbors

Protected Member Functions
	ChSystemGpu ()
	Protected default constructor. Derived class must create m_sys.

void	ReadCsvParticles (std::ifstream &ifile, unsigned int totRow=UINT_MAX)
	Set particle positions, velocities and angular velocities from a CSV ifstream. More...

void	ReadHstHistory (std::ifstream &ifile, unsigned int totItem=UINT_MAX)
	Set particle contact friction history from a hst ifstream. More...

virtual bool	SetParamsFromIdentifier (const std::string &identifier, std::istringstream &iss1, bool overwrite)
	Give a string identifier, set the corresponding simulation parameter, using a switch statement. More...

unsigned int	ReadDatParams (std::ifstream &ifile, bool overwrite)
	Set simulation params from a DAT checkpoint file stream. More...

void	WriteCheckpointParams (std::ofstream &cpFile) const
	Write simulation params to a stream. WriteCheckpointFile() is its wrapper.

void	WriteCsvParticles (std::ofstream &ptFile) const
	Write particle position, velocity and ang. More...

void	WriteRawParticles (std::ofstream &ptFile) const

void	WriteChPFParticles (std::ofstream &ptFile) const

void	WriteHstHistory (std::ofstream &histFile) const
	Write contact pair/history to a stream. More...

void	SetGravitationalAcceleration (const float3 g)
	Set gravitational acceleration as a float3 vector.

Protected Attributes
ChSystemGpu_impl *	m_sys
	underlying system implementation

Member Function Documentation

◆ AdvanceSimulation()

double chrono::gpu::ChSystemGpu::AdvanceSimulation ( float duration )

virtual

Advance simulation by duration in user units, return actual duration elapsed.

Requires Initialize() to have been called.

Reimplemented in chrono::gpu::ChSystemGpuMesh.

◆ Initialize()

void chrono::gpu::ChSystemGpu::Initialize ( )

virtual

Initialize simulation so that it can be advanced.

Must be called before AdvanceSimulation and after simulation parameters are set.

Reimplemented in chrono::gpu::ChSystemGpuMesh.

◆ ReadCsvParticles()

void chrono::gpu::ChSystemGpu::ReadCsvParticles	(	std::ifstream &	ifile,
		unsigned int	totRow = `UINT_MAX`
	)

protected

Set particle positions, velocities and angular velocities from a CSV ifstream.

Methods that read sphere position/velocity info from a file serve as its wrapper.

◆ ReadDatParams()

unsigned int chrono::gpu::ChSystemGpu::ReadDatParams	(	std::ifstream &	ifile,
		bool	overwrite
	)

protected

Set simulation params from a DAT checkpoint file stream.

Returns the number of particles. If instructed to overwrite, then overwrite current simulation parameters with the values in the checkpoint file; else, when an inconsistency is found, throw an error. ReadCheckpointFile() is its wrapper.

◆ ReadHstHistory()

void chrono::gpu::ChSystemGpu::ReadHstHistory	(	std::ifstream &	ifile,
		unsigned int	totItem = `UINT_MAX`
	)

protected

Set particle contact friction history from a hst ifstream.

Methods that read history info from a file serve as its wrapper.

◆ SetBDCenter()

void chrono::gpu::ChSystemGpu::SetBDCenter ( const ChVector< float > & O )

Set the center of the big box domain, relative to the origin of the coordinate system (default: [0,0,0]).

Note that the domain is always axis-aligned. The user must make sure that all simulation information (particle locations, boundaries, meshes...) is consistent with this domain.

◆ SetBDFixed()

void chrono::gpu::ChSystemGpu::SetBDFixed ( bool fixed )

Set the big domain to be fixed or not.

If fixed, it will ignore any given position functions.

◆ SetDefragmentOnInitialize()

void chrono::gpu::ChSystemGpu::SetDefragmentOnInitialize ( bool defragment )

If yes, on Initialize(), particles will have their order re-arranged so that those in the same SD are close together.

This is usually done if starting from scratch, and optional if this is a re-started simulation. Note this is by default on, unless the user loads simulation data from files, in which case it gets disabled.

◆ SetFrictionMode()

void chrono::gpu::ChSystemGpu::SetFrictionMode ( CHGPU_FRICTION_MODE new_mode )

Set friction formulation.

The frictionless setting uses a streamlined solver and avoids storing any physics information associated with friction.

◆ SetParamsFromIdentifier()

bool chrono::gpu::ChSystemGpu::SetParamsFromIdentifier	(	const std::string &	identifier,
		std::istringstream &	iss1,
		bool	overwrite
	)

protectedvirtual

Give a string identifier, set the corresponding simulation parameter, using a switch statement.

ReadDatParams() is its wrapper. It must be virtual, because derived classes also use it (and may call it from a inherited method), and read some more data (thus built on top of it). We must ensure those derived classes call the correct version of it.

◆ SetParticleFixed()

void chrono::gpu::ChSystemGpu::SetParticleFixed ( const std::vector< bool > & fixed )

Set flags indicating whether or not a particle is fixed.

MUST be called only once and MUST be called before Initialize.

◆ SetRollingMode()

void chrono::gpu::ChSystemGpu::SetRollingMode ( CHGPU_ROLLING_MODE new_mode )

Set rolling resistence formulation.

NOTE: This requires friction to be active, otherwise this setting will be ignored.

◆ WriteCheckpointFile()

void chrono::gpu::ChSystemGpu::WriteCheckpointFile ( const std::string & outfilename )

Write a one-stop checkpoint file for Chrono::Gpu.

All information defining a simulation is in this file.

◆ WriteCsvParticles()

void chrono::gpu::ChSystemGpu::WriteCsvParticles ( std::ofstream & ptFile ) const

protected

Write particle position, velocity and ang.

vel. to a stream (of several possible formats). WriteCheckpointFile() and WriteParticleFile() are their wrappers.

◆ WriteHstHistory()

void chrono::gpu::ChSystemGpu::WriteHstHistory ( std::ofstream & histFile ) const

protected

Write contact pair/history to a stream.

WriteCheckpointFile() and WriteContactHistoryFile() are its wrappers.

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

/builds/uwsbel/chrono/src/chrono_gpu/physics/ChSystemGpu.h
/builds/uwsbel/chrono/src/chrono_gpu/physics/ChSystemGpu.cpp

Description

Public Member Functions

Protected Member Functions

Protected Attributes

Member Function Documentation

◆ AdvanceSimulation()

◆ Initialize()

◆ ReadCsvParticles()

◆ ReadDatParams()

◆ ReadHstHistory()

◆ SetBDCenter()

◆ SetBDFixed()

◆ SetDefragmentOnInitialize()

◆ SetFrictionMode()

◆ SetParamsFromIdentifier()

◆ SetParticleFixed()

◆ SetRollingMode()

◆ WriteCheckpointFile()

◆ WriteCsvParticles()

◆ WriteHstHistory()