Description

Chrono Simulation System.

This class is the main simulation object used to collect:

  • the simulation model itself, through the ChAssembly object;
  • the solver and the timestepper;
  • the collision system;
  • system-wise parameters (time, gravitational acceleration, etc.)
  • counters and timers; as well as other secondary features.

This class is in charge of managing dynamic, kinematic and static simulations.

Consult the Simulation system manual page for additional details.

#include <ChSystem.h>

Inheritance diagram for chrono::ChSystem:
Collaboration diagram for chrono::ChSystem:

Classes

class  CustomCollisionCallback
 Class to be used as a callback interface for user defined actions performed at each collision detection step. More...
 

Public Member Functions

 ChSystem ()
 Create a physical system.
 
 ChSystem (const ChSystem &other)
 Copy constructor.
 
virtual ~ChSystem ()
 Destructor.
 
virtual ChSystemClone () const =0
 "Virtual" copy constructor. More...
 
void SetTimestepperType (ChTimestepper::Type type)
 Set the method for time integration (time stepper type). More...
 
ChTimestepper::Type GetTimestepperType () const
 Get the current method for time integration (time stepper type).
 
void SetTimestepper (std::shared_ptr< ChTimestepper > stepper)
 Set the timestepper object to be used for time integration.
 
std::shared_ptr< ChTimestepperGetTimestepper () const
 Get the timestepper currently used for time integration.
 
virtual void SetCollisionSystemType (ChCollisionSystem::Type type)
 Set the collision detection system used by this Chrono system to the specified type.
 
virtual void SetCollisionSystem (std::shared_ptr< ChCollisionSystem > coll_system)
 Set the collision detection system used by this Chrono system.
 
std::shared_ptr< ChCollisionSystemGetCollisionSystem () const
 Access the underlying collision system. More...
 
virtual void SetMaterialCompositionStrategy (std::unique_ptr< ChContactMaterialCompositionStrategy > &&strategy)
 Change the default composition laws for contact surface materials (coefficient of friction, cohesion, compliance, etc.)
 
const ChContactMaterialCompositionStrategyGetMaterialCompositionStrategy () const
 Accessor for the current composition laws for contact surface material.
 
void SetMaxPenetrationRecoverySpeed (double value)
 Set the speed limit of exiting from penetration situations (default: 0.6). More...
 
virtual void SetSolver (std::shared_ptr< ChSolver > newsolver)
 Attach a solver (derived from ChSolver) for use by this system. More...
 
virtual std::shared_ptr< ChSolverGetSolver ()
 Access the solver currently associated with this system.
 
void SetSolverType (ChSolver::Type type)
 Choose the solver type, to be used for the simultaneous solution of the constraints in dynamical simulations (as well as in kinematics, statics, etc.) Notes: More...
 
ChSolver::Type GetSolverType () const
 Gets the current solver type.
 
void SetSystemDescriptor (std::shared_ptr< ChSystemDescriptor > newdescriptor)
 Instead of using the default 'system descriptor', you can create your own custom descriptor (inherited from ChSystemDescriptor) and plug it into the system using this function.
 
std::shared_ptr< ChSystemDescriptorGetSystemDescriptor ()
 Access directly the 'system descriptor'.
 
void SetGravitationalAcceleration (const ChVector3d &gacc)
 Set the gravitational acceleration vector.
 
const ChVector3dGetGravitationalAcceleration () const
 Get the gravitatoinal acceleration vector.
 
double GetChTime () const
 Get the simulation time of this system.
 
void SetChTime (double time)
 Set (overwrite) the simulation time of this system.
 
double GetStep () const
 Gets the current time step used for integration (dynamic and kinematic simulation). More...
 
size_t GetNumSteps () const
 Return the total number of time steps taken so far.
 
void ResetNumSteps ()
 Reset to 0 the total number of time steps.
 
int DoStepDynamics (double step_size)
 Advance the dynamics simulation by a single time step of given length. More...
 
bool DoFrameDynamics (double frame_time, double step_size)
 Advance the dynamics simulation until the specified frame end time is reached. More...
 
AssemblyAnalysis::ExitFlag DoStepKinematics (double step_size)
 Advance the kinematics simulation for a single step of given length.
 
AssemblyAnalysis::ExitFlag DoFrameKinematics (double frame_time, double step_size)
 Advance the kinematics simulation to the specified frame end time. More...
 
bool DoStaticAnalysis (ChStaticAnalysis &analysis)
 Perform a generic static analysis.
 
bool DoStaticLinear ()
 Solve the position of static equilibrium (and the reactions). More...
 
bool DoStaticNonlinear (int nsteps=10, bool verbose=false)
 Solve the position of static equilibrium (and the reactions). More...
 
bool DoStaticNonlinearRheonomic (int max_num_iterations=10, bool verbose=false, std::shared_ptr< ChStaticNonLinearRheonomicAnalysis::IterationCallback > callback=nullptr)
 Solve the position of static equilibrium (and the reactions). More...
 
bool DoStaticRelaxing (double step_size, int num_iterations=10)
 Find the static equilibrium configuration (and the reactions) starting from the current position. More...
 
unsigned int GetSolverSolveCount () const
 Return the number of calls to the solver's Solve() function. More...
 
unsigned int GetSolverSetupCount () const
 Return the number of calls to the solver's Setup() function. More...
 
AssemblyAnalysis::ExitFlag DoAssembly (int action, int max_num_iterationsNR=6, double abstol_residualNR=1e-10, double reltol_updateNR=1e-6, double abstol_updateNR=1e-6)
 Assemble the system. More...
 
unsigned int RemoveRedundantConstraints (bool remove_links=false, double qr_tol=1e-6, bool verbose=false)
 Remove redundant constraints through QR decomposition of the constraints Jacobian matrix. More...
 
virtual void SetNumThreads (int num_threads_chrono, int num_threads_collision=0, int num_threads_eigen=0)
 Set the number of OpenMP threads used by Chrono itself, Eigen, and the collision detection system. More...
 
unsigned int GetNumThreadsChrono () const
 
unsigned int GetNumThreadsCollision () const
 
unsigned int GetNumThreadsEigen () const
 
const ChAssemblyGetAssembly () const
 Get the underlying assembly containing all physics items.
 
virtual void AddBody (std::shared_ptr< ChBody > body)
 Attach a body to the underlying assembly.
 
virtual void AddShaft (std::shared_ptr< ChShaft > shaft)
 Attach a shaft to the underlying assembly.
 
virtual void AddLink (std::shared_ptr< ChLinkBase > link)
 Attach a link to the underlying assembly.
 
virtual void AddMesh (std::shared_ptr< fea::ChMesh > mesh)
 Attach a mesh to the underlying assembly.
 
virtual void AddOtherPhysicsItem (std::shared_ptr< ChPhysicsItem > item)
 Attach a ChPhysicsItem object that is not a body, link, or mesh.
 
void Add (std::shared_ptr< ChPhysicsItem > item)
 Attach an arbitrary ChPhysicsItem (e.g. More...
 
void AddBatch (std::shared_ptr< ChPhysicsItem > item)
 Items added in this way are added like in the Add() method, but not instantly, they are simply queued in a batch of 'to add' items, that are added automatically at the first Setup() call. More...
 
void FlushBatch ()
 If some items are queued for addition in the assembly, using AddBatch(), this will effectively add them and clean the batch. More...
 
virtual void RemoveBody (std::shared_ptr< ChBody > body)
 Remove a body from this assembly.
 
virtual void RemoveShaft (std::shared_ptr< ChShaft > shaft)
 Remove a shaft from this assembly.
 
virtual void RemoveLink (std::shared_ptr< ChLinkBase > link)
 Remove a link from this assembly.
 
virtual void RemoveMesh (std::shared_ptr< fea::ChMesh > mesh)
 Remove a mesh from the assembly.
 
virtual void RemoveOtherPhysicsItem (std::shared_ptr< ChPhysicsItem > item)
 Remove a ChPhysicsItem object that is not a body or a link.
 
void Remove (std::shared_ptr< ChPhysicsItem > item)
 Remove arbitrary ChPhysicsItem that was added to the underlying assembly.
 
void RemoveAllBodies ()
 Remove all bodies from the underlying assembly.
 
void RemoveAllShafts ()
 Remove all shafts from the underlying assembly.
 
void RemoveAllLinks ()
 Remove all links from the underlying assembly.
 
void RemoveAllMeshes ()
 Remove all meshes from the underlying assembly.
 
void RemoveAllOtherPhysicsItems ()
 Remove all physics items not in the body, link, or mesh lists.
 
const std::vector< std::shared_ptr< ChBody > > & GetBodies () const
 Get the list of bodies.
 
const std::vector< std::shared_ptr< ChShaft > > & GetShafts () const
 Get the list of shafts.
 
const std::vector< std::shared_ptr< ChLinkBase > > & GetLinks () const
 Get the list of links.
 
const std::vector< std::shared_ptr< fea::ChMesh > > & GetMeshes () const
 Get the list of meshes.
 
const std::vector< std::shared_ptr< ChPhysicsItem > > & GetOtherPhysicsItems () const
 Get the list of physics items that are not in the body or link lists.
 
std::shared_ptr< ChBodySearchBody (const std::string &name) const
 Search a body by its name.
 
std::shared_ptr< ChBodySearchBodyID (int id) const
 Search a body by its ID.
 
std::shared_ptr< ChShaftSearchShaft (const std::string &name) const
 Search a shaft by its name.
 
std::shared_ptr< ChLinkBaseSearchLink (const std::string &name) const
 Search a link by its name.
 
std::shared_ptr< fea::ChMeshSearchMesh (const std::string &name) const
 Search a mesh by its name.
 
std::shared_ptr< ChPhysicsItemSearchOtherPhysicsItem (const std::string &name) const
 Search from other ChPhysics items (not bodies, links, or meshes) by name.
 
std::shared_ptr< ChMarkerSearchMarker (const std::string &name) const
 Search a marker by its name.
 
std::shared_ptr< ChMarkerSearchMarker (int id) const
 Search a marker by its unique ID.
 
std::shared_ptr< ChPhysicsItemSearch (const std::string &name) const
 Search an item (body, link or other ChPhysics items) by name.
 
virtual unsigned int GetNumBodies () const
 Get the total number of bodies added to the system, including fixed and sleeping bodies.
 
virtual unsigned int GetNumBodiesActive () const
 Get the number of active bodies, excluding sleeping or fixed.
 
virtual unsigned int GetNumBodiesSleeping () const
 Get the number of sleeping bodies.
 
virtual unsigned int GetNumBodiesFixed () const
 Get the number of bodies fixed to ground.
 
virtual unsigned int GetNumShafts () const
 Get the number of shafts.
 
virtual unsigned int GetNumShaftsSleeping () const
 Get the number of shafts that are in sleeping mode (excluding fixed shafts).
 
virtual unsigned int GetNumShaftsFixed () const
 Get the number of shafts that are fixed to ground.
 
virtual unsigned int GetNumShaftsTotal () const
 Get the total number of shafts added to the assembly, including the grounded and sleeping shafts.
 
virtual unsigned int GetNumLinks () const
 Get the number of links (including non active).
 
virtual unsigned int GetNumLinksActive () const
 Get the number of active links.
 
virtual unsigned int GetNumMeshes () const
 Get the number of meshes.
 
virtual unsigned int GetNumOtherPhysicsItems () const
 Get the number of other physics items (including non active).
 
virtual unsigned int GetNumOtherPhysicsItemsActive () const
 Get the number of other active physics items.
 
void ShowHierarchy (std::ostream &m_file, int level=0) const
 Write the hierarchy of contained bodies, markers, etc. More...
 
void Clear ()
 Removes all bodies/marker/forces/links/contacts, also resets timers and events.
 
virtual ChContactMethod GetContactMethod () const =0
 Return the contact method supported by this system. More...
 
virtual void CustomEndOfStep ()
 Executes custom processing at the end of step. More...
 
double ComputeCollisions ()
 Perform the collision detection. More...
 
void RegisterCustomCollisionCallback (std::shared_ptr< CustomCollisionCallback > callback)
 Specify a callback object to be invoked at each collision detection step. More...
 
void UnregisterCustomCollisionCallback (std::shared_ptr< CustomCollisionCallback > callback)
 Remove the given collision callback from this system.
 
virtual void SetContactContainer (std::shared_ptr< ChContactContainer > container)
 Change the underlying contact container. More...
 
std::shared_ptr< ChContactContainerGetContactContainer () const
 Access the underlying contact container. More...
 
void SetSleepingAllowed (bool ms)
 Turn on this feature to let the system put to sleep the bodies whose motion has almost come to a rest. More...
 
bool IsSleepingAllowed () const
 Tell if the system will put to sleep the bodies whose motion has almost come to a rest.
 
ChVisualSystemGetVisualSystem () const
 Get the visual system to which this ChSystem is attached (if any).
 
virtual unsigned int GetNumContacts ()
 Gets the number of contacts.
 
virtual double GetTimerStep () const
 Return the time (in seconds) spent for computing the time step.
 
virtual double GetTimerAdvance () const
 Return the time (in seconds) for time integration, within the time step.
 
virtual double GetTimerLSsolve () const
 Return the time (in seconds) for the solver, within the time step. More...
 
virtual double GetTimerLSsetup () const
 Return the time (in seconds) for the solver Setup phase, within the time step.
 
virtual double GetTimerJacobian () const
 Return the time (in seconds) for calculating/loading Jacobian information, within the time step.
 
virtual double GetTimerCollision () const
 Return the time (in seconds) for runnning the collision detection step, within the time step.
 
virtual double GetTimerSetup () const
 Return the time (in seconds) for system setup, within the time step.
 
virtual double GetTimerUpdate () const
 Return the time (in seconds) for updating auxiliary data, within the time step.
 
double GetTimerCollisionBroad () const
 Return the time (in seconds) for broadphase collision detection, within the time step.
 
double GetTimerCollisionNarrow () const
 Return the time (in seconds) for narrowphase collision detection, within the time step.
 
double GetRTF () const
 Get current estimated RTF (real time factor). More...
 
void SetRTF (double rtf)
 Set (overwrite) the RTF value for this system (if calculated externally).
 
void ResetTimers ()
 Resets the timers.
 
void EnableSolverMatrixWrite (bool val, const std::string &out_dir=".")
 DEBUGGING. More...
 
bool IsSolverMatrixWriteEnabled () const
 Return true if solver matrices are being written to disk.
 
void WriteSystemMatrices (bool save_M, bool save_K, bool save_R, bool save_Cq, const std::string &path, bool one_indexed=true)
 Write the mass (M), damping (R), stiffness (K), and constraint Jacobian (Cq) matrices at current configuration. More...
 
void GetMassMatrix (ChSparseMatrix &M)
 Compute the system-level mass matrix and load in the provided sparse matrix.
 
void GetStiffnessMatrix (ChSparseMatrix &K)
 Compute the system-level stiffness matrix and load in the provided sparse matrix. More...
 
void GetDampingMatrix (ChSparseMatrix &R)
 Compute the system-level damping matrix and load in the provided sparse matrix. More...
 
void GetConstraintJacobianMatrix (ChSparseMatrix &Cq)
 Compute the system-level constraint Jacobian matrix and load in the provided sparse matrix. More...
 
virtual void ArchiveOut (ChArchiveOut &archive_out)
 Method to allow serialization of transient data to archives.
 
virtual void ArchiveIn (ChArchiveIn &archive_in)
 Method to allow deserialization of transient data from archives.
 
virtual void Setup ()
 Counts the number of bodies and links. More...
 
void Update (double mytime, bool update_assets=true)
 Updates all the auxiliary data and children of bodies, forces, links, given their current state.
 
void Update (bool update_assets=true)
 Updates all the auxiliary data and children of bodies, forces, links, given their current state.
 
void ForceUpdate ()
 In normal usage, no system update is necessary at the beginning of a new dynamics step (since an update is performed at the end of a step). More...
 
void IntToDescriptor (const unsigned int off_v, const ChStateDelta &v, const ChVectorDynamic<> &R, const unsigned int off_L, const ChVectorDynamic<> &L, const ChVectorDynamic<> &Qc)
 
void IntFromDescriptor (const unsigned int off_v, ChStateDelta &v, const unsigned int off_L, ChVectorDynamic<> &L)
 
void InjectVariables (ChSystemDescriptor &sys_descriptor)
 Register with the given system descriptor all ChVariable objects associated with items in the system.
 
void InjectConstraints (ChSystemDescriptor &sys_descriptor)
 Register with the given system descriptor any ChConstraint objects associated with items in the system.
 
void LoadConstraintJacobians ()
 Compute and load current Jacobians in encapsulated ChConstraint objects.
 
void InjectKRMMatrices (ChSystemDescriptor &sys_descriptor)
 Register with the given system descriptor any ChKRMBlock objects associated with items in the system.
 
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...
 
void VariablesFbReset ()
 
void VariablesFbLoadForces (double factor=1)
 
void VariablesQbLoadSpeed ()
 
void VariablesFbIncrementMq ()
 
void VariablesQbSetSpeed (double step=0)
 
void VariablesQbIncrementPosition (double step)
 
void ConstraintsBiReset ()
 
void ConstraintsBiLoad_C (double factor=1, double recovery_clamp=0.1, bool do_clamp=false)
 
void ConstraintsBiLoad_Ct (double factor=1)
 
void ConstraintsBiLoad_Qc (double factor=1)
 
void ConstraintsFbLoadForces (double factor=1)
 
void ConstraintsFetch_react (double factor=1)
 
virtual unsigned int GetNumCoordsPosLevel () override
 Get the number of coordinates at the position level. More...
 
virtual unsigned int GetNumCoordsVelLevel () override
 Get the number of coordinates at the velocity level. More...
 
virtual unsigned int GetNumConstraints () override
 Get the number of scalar constraints in the system.
 
virtual unsigned int GetNumConstraintsBilateral ()
 Get the number of bilateral scalar constraints.
 
virtual unsigned int GetNumConstraintsUnilateral ()
 Get the number of unilateral scalar constraints.
 
virtual void StateGather (ChState &x, ChStateDelta &v, double &T) override
 From system to state y={x,v}.
 
virtual void StateScatter (const ChState &x, const ChStateDelta &v, const double T, bool full_update) override
 From state Y={x,v} to system. This also triggers an update operation.
 
virtual void StateGatherAcceleration (ChStateDelta &a) override
 From system to state derivative (acceleration), some timesteppers might need last computed accel.
 
virtual void StateScatterAcceleration (const ChStateDelta &a) override
 From state derivative (acceleration) to system, sometimes might be needed.
 
virtual void StateGatherReactions (ChVectorDynamic<> &L) override
 From system to reaction forces (last computed) - some timestepper might need this.
 
virtual void StateScatterReactions (const ChVectorDynamic<> &L) override
 From reaction forces to system, ex. store last computed reactions in ChLink objects for plotting etc.
 
virtual void StateIncrementX (ChState &x_new, const ChState &x, const ChStateDelta &Dx) override
 Perform x_new = x + dx, for x in Y = {x, dx/dt}. More...
 
virtual bool StateSolveCorrection (ChStateDelta &Dv, ChVectorDynamic<> &DL, const ChVectorDynamic<> &R, const ChVectorDynamic<> &Qc, const double c_a, const double c_v, const double c_x, const ChState &x, const ChStateDelta &v, const double T, bool force_state_scatter, bool full_update, bool force_setup) override
 Assuming a DAE of the form. More...
 
virtual void LoadResidual_F (ChVectorDynamic<> &R, const double c) override
 Increment a vector R with the term c*F: R += c*F. More...
 
virtual void LoadResidual_Mv (ChVectorDynamic<> &R, const ChVectorDynamic<> &w, const double c) override
 Increment a vector R with a term that has M multiplied a given vector w: R += c*M*w. More...
 
virtual void LoadLumpedMass_Md (ChVectorDynamic<> &Md, double &err, const double c) override
 Adds the lumped mass to a Md vector, representing a mass diagonal matrix. More...
 
virtual void LoadResidual_CqL (ChVectorDynamic<> &R, const ChVectorDynamic<> &L, const double c) override
 Increment a vectorR with the term Cq'*L: R += c*Cq'*L. More...
 
virtual void LoadConstraint_C (ChVectorDynamic<> &Qc, const double c, const bool do_clamp=false, const double clamp=1e30) override
 Increment a vector Qc with the term C: Qc += c*C. More...
 
virtual void LoadConstraint_Ct (ChVectorDynamic<> &Qc, const double c) override
 Increment a vector Qc with the term Ct = partial derivative dC/dt: Qc += c*Ct. More...
 
- Public Member Functions inherited from chrono::ChIntegrableIIorder
virtual void StateSetup (ChState &x, ChStateDelta &v, ChStateDelta &a)
 Set up the system state with separate II order components x, v, a for y = {x, v} and dy/dt={v, a}.
 
virtual bool StateSolveA (ChStateDelta &Dvdt, ChVectorDynamic<> &L, const ChState &x, const ChStateDelta &v, const double T, const double dt, bool force_state_scatter, bool full_update, ChLumpingParms *lumping=nullptr)
 Solve for accelerations: a = f(x,v,t) Given current state y={x,v} , computes acceleration a in the state derivative dy/dt={v,a} and lagrangian multipliers L (if any). More...
 
virtual void StateGather (ChState &y, double &T) override
 Gather system state in specified array. More...
 
virtual void StateScatter (const ChState &y, const double T, bool full_update) override
 Scatter the states from the provided array to the system. More...
 
virtual void StateGatherDerivative (ChStateDelta &Dydt) override
 Gather from the system the state derivatives in specified array. More...
 
virtual void StateScatterDerivative (const ChStateDelta &Dydt) override
 Scatter the state derivatives from the provided array to the system. More...
 
virtual void StateIncrement (ChState &y_new, const ChState &y, const ChStateDelta &Dy) override
 Increment state array: y_new = y + Dy. More...
 
virtual bool StateSolve (ChStateDelta &dydt, ChVectorDynamic<> &L, const ChState &y, const double T, const double dt, bool force_state_scatter, bool full_update, ChLumpingParms *lumping=nullptr) override
 Solve for state derivatives: dy/dt = f(y,t). More...
 
virtual bool StateSolveCorrection (ChStateDelta &Dy, ChVectorDynamic<> &L, const ChVectorDynamic<> &R, const ChVectorDynamic<> &Qc, const double a, const double b, const ChState &y, const double T, const double dt, bool force_state_scatter, bool full_update, bool force_setup) override final
 Override of method for Ist order implicit integrators. More...
 
- Public Member Functions inherited from chrono::ChIntegrable
virtual unsigned int GetNumCoordsAccLevel ()
 Return the number of coordinates at the acceleration level.
 
virtual void StateSetup (ChState &y, ChStateDelta &dy)
 Set up the system state.
 
virtual void LoadResidual_Hv (ChVectorDynamic<> &R, const ChVectorDynamic<> &v, const double c)
 Increment a vector R (usually the residual in a Newton Raphson iteration for solving an implicit integration step) with a term that has H multiplied a given vector w: R += c*H*w. More...
 

Protected Member Functions

virtual void DescriptorPrepareInject (ChSystemDescriptor &sys_descriptor)
 Pushes all ChConstraints and ChVariables contained in links, bodies, etc. into the system descriptor.
 
void Initialize ()
 Initial system setup before analysis. More...
 
virtual ChVector3d GetBodyAppliedForce (ChBody *body)
 Return the resultant applied force on the specified body. More...
 
virtual ChVector3d GetBodyAppliedTorque (ChBody *body)
 Return the resultant applied torque on the specified body. More...
 
bool ManageSleepingBodies ()
 Put bodies to sleep if possible. More...
 
virtual bool AdvanceDynamics ()
 Performs a single dynamics simulation step, advancing the system state by the current step size.
 

Protected Attributes

ChAssembly assembly
 underlying mechanical assembly
 
std::shared_ptr< ChContactContainercontact_container
 the container of contacts
 
ChVector3d G_acc
 gravitational acceleration
 
bool is_initialized
 if false, an initial setup is required (i.e. a call to Initialize)
 
bool is_updated
 if false, a new update is required (i.e. a call to Update)
 
unsigned int m_num_coords_pos
 num of scalar coordinates at position level for all active bodies
 
unsigned int m_num_coords_vel
 num of scalar coordinates at velocity level for all active bodies
 
unsigned int m_num_constr
 num of scalar constraints (at velocity level) for all active constraints
 
unsigned int m_num_constr_bil
 num of scalar bilateral active constraints (velocity level)
 
unsigned int m_num_constr_uni
 num of scalar unilateral active constraints (velocity level)
 
double ch_time
 simulation time of the system
 
double step
 time step
 
bool use_sleeping
 if true, put to sleep objects that come to rest
 
std::shared_ptr< ChSystemDescriptordescriptor
 system descriptor
 
std::shared_ptr< ChSolversolver
 solver for DVI or DAE problem
 
double max_penetration_recovery_speed
 limit for speed of penetration recovery (positive)
 
size_t stepcount
 internal counter for steps
 
unsigned int setupcount
 number of calls to the solver's Setup()
 
unsigned int solvecount
 number of StateSolveCorrection (reset to 0 at each timestep of static analysis)
 
bool write_matrix
 write current system matrix to file(s); for debugging
 
std::string output_dir
 output directory for writing system matrices
 
unsigned int ncontacts
 total number of contacts
 
std::shared_ptr< ChCollisionSystemcollision_system
 collision engine
 
std::vector< std::shared_ptr< CustomCollisionCallback > > collision_callbacks
 user-defined collision callbacks
 
std::unique_ptr< ChContactMaterialCompositionStrategycomposition_strategy
 
ChVisualSystemvisual_system
 material composition strategy More...
 
int nthreads_chrono
 
int nthreads_eigen
 
int nthreads_collision
 
ChTimer timer_step
 timer for integration step
 
ChTimer timer_advance
 timer for time integration
 
ChTimer timer_ls_solve
 timer for solver (excluding setup phase)
 
ChTimer timer_ls_setup
 timer for solver setup
 
ChTimer timer_jacobian
 timer for computing/loading Jacobian information
 
ChTimer timer_collision
 timer for collision detection
 
ChTimer timer_setup
 timer for system setup
 
ChTimer timer_update
 timer for system update
 
double m_RTF
 real-time factor (simulation time / simulated time)
 
std::shared_ptr< ChTimesteppertimestepper
 time-stepper object
 
ChVectorDynamic applied_forces
 system-wide vector of applied forces (lazy evaluation)
 
bool applied_forces_current
 indicates if system-wide vector of forces is up-to-date
 

Friends

class ChAssembly
 
class ChBody
 
class fea::ChMesh
 
class ChContactContainerNSC
 
class ChContactContainerSMC
 
class ChVisualSystem
 
class ChCollisionSystem
 
class modal::ChModalAssembly
 

Member Function Documentation

◆ Add()

void chrono::ChSystem::Add ( std::shared_ptr< ChPhysicsItem item)

Attach an arbitrary ChPhysicsItem (e.g.

ChBody, ChParticles, ChLink, etc.) to the assembly. It will take care of adding it to the proper list of bodies, links, meshes, or generic physic item. (i.e. it calls AddBody, AddShaft(), AddLink(), AddMesh(), or AddOtherPhysicsItem()). Note, you cannot call Add() during an Update (i.e. items like particle generators that are already inserted in the assembly cannot call this) because not thread safe; instead, use AddBatch().

◆ AddBatch()

void chrono::ChSystem::AddBatch ( std::shared_ptr< ChPhysicsItem item)
inline

Items added in this way are added like in the Add() method, but not instantly, they are simply queued in a batch of 'to add' items, that are added automatically at the first Setup() call.

This is thread safe.

◆ Clone()

virtual ChSystem* chrono::ChSystem::Clone ( ) const
pure virtual

"Virtual" copy constructor.

Concrete derived classes must implement this.

Implemented in chrono::ChSystemMulticoreSMC, chrono::ChSystemMulticoreNSC, chrono::ChSystemSMC, and chrono::ChSystemNSC.

◆ ComputeCollisions()

double chrono::ChSystem::ComputeCollisions ( )

Perform the collision detection.

New contacts are inserted in the ChContactContainer object(s), and old ones are removed. This is mostly called automatically by time integration.

◆ CustomEndOfStep()

virtual void chrono::ChSystem::CustomEndOfStep ( )
inlinevirtual

Executes custom processing at the end of step.

By default it does nothing, but if you inherit a special ChSystem you can implement this.

◆ DoAssembly()

AssemblyAnalysis::ExitFlag chrono::ChSystem::DoAssembly ( int  action,
int  max_num_iterationsNR = 6,
double  abstol_residualNR = 1e-10,
double  reltol_updateNR = 1e-6,
double  abstol_updateNR = 1e-6 
)

Assemble the system.

The assembling is performed by satisfying constraints at position, velocity, and acceleration levels. Position-level assembling requires Newton-Raphson iterations. Velocity-level assembling is performed by taking a small integration step. Acceleration-level assembling is obtained through finite differentation. Argument 'action' can be one of AssemblyLevel enum values (POSITION, VELOCITY, ACCELERATION, or FULL). These values can also be combined using bit operations. Returns true if the assembling converged, false otherwise (impossible assembly?) The maximum number of iterations and the tolerance refer to the Newton-Raphson iteration for position-level. Iterations and tolerance for the inner linear solver must be set on the solver itself.

◆ DoFrameDynamics()

bool chrono::ChSystem::DoFrameDynamics ( double  frame_time,
double  step_size 
)

Advance the dynamics simulation until the specified frame end time is reached.

Integration proceeds with the specified time step size which may be adjusted to exactly reach the frame time.

◆ DoFrameKinematics()

AssemblyAnalysis::ExitFlag chrono::ChSystem::DoFrameKinematics ( double  frame_time,
double  step_size 
)

Advance the kinematics simulation to the specified frame end time.

A system assembly analysis (inverse kinematics) is performed at step_size intervals. The last step may be adjusted to exactly reach the frame end time.

◆ DoStaticLinear()

bool chrono::ChSystem::DoStaticLinear ( )

Solve the position of static equilibrium (and the reactions).

This is a one-step only approach that solves the linear equilibrium. Appropriate mostly for FEM problems with small deformations.

◆ DoStaticNonlinear()

bool chrono::ChSystem::DoStaticNonlinear ( int  nsteps = 10,
bool  verbose = false 
)

Solve the position of static equilibrium (and the reactions).

This function solves the equilibrium for the nonlinear problem (large displacements). This version uses a nonlinear static analysis solver with default parameters.

◆ DoStaticNonlinearRheonomic()

bool chrono::ChSystem::DoStaticNonlinearRheonomic ( int  max_num_iterations = 10,
bool  verbose = false,
std::shared_ptr< ChStaticNonLinearRheonomicAnalysis::IterationCallback callback = nullptr 
)

Solve the position of static equilibrium (and the reactions).

This function solves the equilibrium for the nonlinear problem (large displacements), but differently from DoStaticNonlinear it considers rheonomic constraints (ex. ChLinkMotorRotationSpeed) that can impose steady-state speeds&accelerations to the mechanism, ex. to generate centrifugal forces in turbine blades. This version uses a nonlinear static analysis solver with default parameters.

◆ DoStaticRelaxing()

bool chrono::ChSystem::DoStaticRelaxing ( double  step_size,
int  num_iterations = 10 
)

Find the static equilibrium configuration (and the reactions) starting from the current position.

Since a truncated iterative method is used, you may need to call this method multiple times in case of large nonlinearities before coming to the precise static solution.

◆ DoStepDynamics()

int chrono::ChSystem::DoStepDynamics ( double  step_size)

Advance the dynamics simulation by a single time step of given length.

This function is typically called many times in a loop in order to simulate up to a desired end time.

◆ EnableSolverMatrixWrite()

void chrono::ChSystem::EnableSolverMatrixWrite ( bool  val,
const std::string &  out_dir = "." 
)

DEBUGGING.

Enable/disable debug output of system matrices. Set this to "true" to enable automatic saving of solver matrices at each time step, for debugging purposes. Matrices will be saved in 'out_dir' (default to the the working directory of the executable). The name pattern is solve_numstep_numsubstep_objectname.dat where 'objectname' can be either:

  • Z: the assembled optimization matrix [H, -Cq'; Cq, -E]
  • rhs: the assembled right-hand side vector [f; -b]
  • x_pre: the position vector before the integration step
  • v_pre: the velocity vector before the integration step
  • F_pre: unscaled loads before the integration step
  • Dv: the state variation
  • Dl: the lagrangian multipliers variation if the solver is direct then also the following are output:
  • f, b: subparts of 'rhs'
  • H, Cq, E: the submatrices of Z as passed to the solver in the problem
    | H  Cq'|*| q|-| f|=|0|
    | Cq  E | |-l| |-b| |c|
    
    where l \(\in Y, c \in Ny\), normal cone to Y

◆ FlushBatch()

void chrono::ChSystem::FlushBatch ( )
inline

If some items are queued for addition in the assembly, using AddBatch(), this will effectively add them and clean the batch.

Called automatically at each Setup().

◆ ForceUpdate()

void chrono::ChSystem::ForceUpdate ( )

In normal usage, no system update is necessary at the beginning of a new dynamics step (since an update is performed at the end of a step).

However, this is not the case if external changes to the system are made. Most such changes are discovered automatically (addition/removal of items, input of mesh loads). For special cases, this function allows the user to trigger a system update at the beginning of the step immediately following this call.

◆ GetBodyAppliedForce()

ChVector3d chrono::ChSystem::GetBodyAppliedForce ( ChBody body)
protectedvirtual

Return the resultant applied force on the specified body.

This resultant force includes all external applied loads acting on the body (from gravity, loads, springs, etc). However, this does not include any constraint forces. In particular, contact forces are not included if using the NSC formulation, but are included when using the SMC formulation.

Reimplemented in chrono::ChSystemMulticore.

◆ GetBodyAppliedTorque()

ChVector3d chrono::ChSystem::GetBodyAppliedTorque ( ChBody body)
protectedvirtual

Return the resultant applied torque on the specified body.

This resultant torque includes all external applied loads acting on the body (from gravity, loads, springs, etc). However, this does not include any constraint forces. In particular, contact torques are not included if using the NSC formulation, but are included when using the SMC formulation.

Reimplemented in chrono::ChSystemMulticore.

◆ GetCollisionSystem()

std::shared_ptr<ChCollisionSystem> chrono::ChSystem::GetCollisionSystem ( ) const
inline

Access the underlying collision system.

Usually this is not needed, as the collision system is automatically handled by the ChSystem.

◆ GetConstraintJacobianMatrix()

void chrono::ChSystem::GetConstraintJacobianMatrix ( ChSparseMatrix Cq)

Compute the system-level constraint Jacobian matrix and load in the provided sparse matrix.

This is the Jacobian Cq=-dC/dq, where C are constraints (the lower left part of the KKT matrix).

◆ GetContactContainer()

std::shared_ptr<ChContactContainer> chrono::ChSystem::GetContactContainer ( ) const
inline

Access the underlying contact container.

Usually this is not needed, as the contact container is automatically handled by the ChSystem.

◆ GetContactMethod()

virtual ChContactMethod chrono::ChSystem::GetContactMethod ( ) const
pure virtual

Return the contact method supported by this system.

Contactables (bodies, FEA nodes, FEA traiangles, etc.) added to this system must be compatible.

Implemented in chrono::ChSystemNSC, chrono::ChSystemMulticoreSMC, chrono::ChSystemMulticoreNSC, and chrono::ChSystemSMC.

◆ GetDampingMatrix()

void chrono::ChSystem::GetDampingMatrix ( ChSparseMatrix R)

Compute the system-level damping matrix and load in the provided sparse matrix.

This is the Jacobian -dF/dv, where F are stiff loads. Note that not all loads provide a Jacobian, as this is optional in their implementation.

◆ GetNumCoordsPosLevel()

virtual unsigned int chrono::ChSystem::GetNumCoordsPosLevel ( )
inlineoverridevirtual

Get the number of coordinates at the position level.

Might differ from coordinates at the velocity level if quaternions are used for rotations.

Implements chrono::ChIntegrable.

◆ GetNumCoordsVelLevel()

virtual unsigned int chrono::ChSystem::GetNumCoordsVelLevel ( )
inlineoverridevirtual

Get the number of coordinates at the velocity level.

Might differ from coordinates at the position level if quaternions are used for rotations.

Implements chrono::ChIntegrable.

◆ GetRTF()

double chrono::ChSystem::GetRTF ( ) const
inline

Get current estimated RTF (real time factor).

This represents the real time factor for advancing the dynamic state of the system only and as such does not take into account any other operations performed during a step (e.g., run-time visualization). During each call to DoStepDynamics(), this value is calculated as T/step_size, where T includes the time spent in system setup, collision detection, and integration.

◆ GetSolverSetupCount()

unsigned int chrono::ChSystem::GetSolverSetupCount ( ) const
inline

Return the number of calls to the solver's Setup() function.

This counter is reset at each timestep.

◆ GetSolverSolveCount()

unsigned int chrono::ChSystem::GetSolverSolveCount ( ) const
inline

Return the number of calls to the solver's Solve() function.

This counter is reset at each timestep.

◆ GetStep()

double chrono::ChSystem::GetStep ( ) const
inline

Gets the current time step used for integration (dynamic and kinematic simulation).

The value is set automatically when a dynamic or kinematic simulation is run.

◆ GetStiffnessMatrix()

void chrono::ChSystem::GetStiffnessMatrix ( ChSparseMatrix K)

Compute the system-level stiffness matrix and load in the provided sparse matrix.

This is the Jacobian -dF/dq, where F are stiff loads. Note that not all loads provide a jacobian, as this is optional in their implementation.

◆ GetTimerLSsolve()

virtual double chrono::ChSystem::GetTimerLSsolve ( ) const
inlinevirtual

Return the time (in seconds) for the solver, within the time step.

Note that this time excludes any calls to the solver's Setup function.

Reimplemented in chrono::ChSystemMulticore.

◆ Initialize()

void chrono::ChSystem::Initialize ( )
protected

Initial system setup before analysis.

This function performs an initial system setup, once system construction is completed and before an analysis. This function also initializes the collision system (if any), as well as any visualization system to which this Chrono system was attached. The initialization function is called automatically before starting any type of analysis.

◆ LoadConstraint_C()

void chrono::ChSystem::LoadConstraint_C ( ChVectorDynamic<> &  Qc,
const double  c,
const bool  do_clamp = false,
const double  clamp = 1e30 
)
overridevirtual

Increment a vector Qc with the term C: Qc += c*C.

Parameters
Qcresult: the Qc residual, Qc += c*C
ca scaling factor
do_clampenable optional clamping of Qc
clampclamping value

Reimplemented from chrono::ChIntegrableIIorder.

◆ LoadConstraint_Ct()

void chrono::ChSystem::LoadConstraint_Ct ( ChVectorDynamic<> &  Qc,
const double  c 
)
overridevirtual

Increment a vector Qc with the term Ct = partial derivative dC/dt: Qc += c*Ct.

Parameters
Qcresult: the Qc residual, Qc += c*Ct
ca scaling factor

Reimplemented from chrono::ChIntegrableIIorder.

◆ LoadKRMMatrices()

void chrono::ChSystem::LoadKRMMatrices ( double  Kfactor,
double  Rfactor,
double  Mfactor 
)

Compute and load current stiffnes (K), damping (R), and mass (M) matrices in encapsulated ChKRMBlock objects.

The resulting KRM blocks represent linear combinations of the K, R, and M matrices, with the specified coefficients Kfactor, Rfactor,and Mfactor, respectively.

◆ LoadLumpedMass_Md()

void chrono::ChSystem::LoadLumpedMass_Md ( ChVectorDynamic<> &  Md,
double &  err,
const double  c 
)
overridevirtual

Adds the lumped mass to a Md vector, representing a mass diagonal matrix.

Used by lumped explicit integrators. If mass lumping is impossible or approximate, adds scalar error to "error" parameter. Md += c*diag(M) or Md += c*HRZ(M)

Parameters
Mdresult: Md vector, diagonal of the lumped mass matrix
errresult: not touched if lumping does not introduce errors
ca scaling factor

Reimplemented from chrono::ChIntegrableIIorder.

◆ LoadResidual_CqL()

void chrono::ChSystem::LoadResidual_CqL ( ChVectorDynamic<> &  R,
const ChVectorDynamic<> &  L,
const double  c 
)
overridevirtual

Increment a vectorR with the term Cq'*L: R += c*Cq'*L.

Parameters
Rresult: the R residual, R += c*Cq'*L
Lthe L vector
ca scaling factor

Reimplemented from chrono::ChIntegrableIIorder.

◆ LoadResidual_F()

void chrono::ChSystem::LoadResidual_F ( ChVectorDynamic<> &  R,
const double  c 
)
overridevirtual

Increment a vector R with the term c*F: R += c*F.

Parameters
Rresult: the R residual, R += c*F
ca scaling factor

Reimplemented from chrono::ChIntegrableIIorder.

◆ LoadResidual_Mv()

void chrono::ChSystem::LoadResidual_Mv ( ChVectorDynamic<> &  R,
const ChVectorDynamic<> &  w,
const double  c 
)
overridevirtual

Increment a vector R with a term that has M multiplied a given vector w: R += c*M*w.

Parameters
Rresult: the R residual, R += c*M*v
wthe w vector
ca scaling factor

Reimplemented from chrono::ChIntegrableIIorder.

◆ ManageSleepingBodies()

bool chrono::ChSystem::ManageSleepingBodies ( )
protected

Put bodies to sleep if possible.

Also awakens sleeping bodies, if needed. Returns true if some body changed from sleep to no sleep or viceversa, returns false if nothing changed. In the former case also performs Setup() since the system changed.

If some body still must change from no sleep-> sleep, do it

◆ RegisterCustomCollisionCallback()

void chrono::ChSystem::RegisterCustomCollisionCallback ( std::shared_ptr< CustomCollisionCallback callback)

Specify a callback object to be invoked at each collision detection step.

Multiple such callback objects can be registered with a system. If present, their OnCustomCollision() method is invoked. Use this if you want that some specific callback function is executed at each collision detection step (ex. all the times that ComputeCollisions() is automatically called by the integration method). For example some other collision engine could add further contacts using this callback.

◆ RemoveRedundantConstraints()

unsigned int chrono::ChSystem::RemoveRedundantConstraints ( bool  remove_links = false,
double  qr_tol = 1e-6,
bool  verbose = false 
)

Remove redundant constraints through QR decomposition of the constraints Jacobian matrix.

Remove redundant constraints present in ChSystem through QR decomposition of constraints Jacobian matrix.

This function can be used to improve the stability and performance of the system by removing redundant constraints. The function returns the number of redundant constraints that were deactivated/removed. Please consider that some constraints might falsely appear as redundant in a specific configuration, while they might be not in general.

Parameters
remove_linksfalse: redundant links are just deactivated; true: redundant links get removed
qr_toltolerance in QR decomposition to identify linearly dependent constraints
verboseset verbose output

◆ SetContactContainer()

void chrono::ChSystem::SetContactContainer ( std::shared_ptr< ChContactContainer container)
virtual

Change the underlying contact container.

The contact container collects information from the underlying collision detection system required for contact force generation. Usually this is not needed, as the contact container is automatically handled by the ChSystem. Make sure the provided contact container is compatible with both the collision detection system and the contact force formulation (NSC or SMC).

Reimplemented in chrono::ChSystemMulticoreSMC, chrono::ChSystemMulticoreNSC, chrono::ChSystemSMC, and chrono::ChSystemNSC.

◆ SetMaxPenetrationRecoverySpeed()

void chrono::ChSystem::SetMaxPenetrationRecoverySpeed ( double  value)
inline

Set the speed limit of exiting from penetration situations (default: 0.6).

Usually set a positive value, (about 0.1...2 m/s, as exiting speed). Used for unilateral constraints with the EULER_IMPLICIT_LINEARIZED time stepper.

◆ SetNumThreads()

void chrono::ChSystem::SetNumThreads ( int  num_threads_chrono,
int  num_threads_collision = 0,
int  num_threads_eigen = 0 
)
virtual

Set the number of OpenMP threads used by Chrono itself, Eigen, and the collision detection system.

  num_threads_chrono    - used in FEA (parallel evaluation of internal forces and Jacobians) and
                          in SCM deformable terrain calculations.
  num_threads_collision - used in parallelization of collision detection (if applicable).
                          If passing 0, then num_threads_collision = num_threads_chrono.
  num_threads_eigen     - used in the Eigen sparse direct solvers and a few linear algebra operations.
                          Note that Eigen enables multi-threaded execution only under certain size conditions.
                          See the Eigen documentation.
                          If passing 0, then num_threads_eigen = num_threads_chrono.
By default (if this function is not called), the following values are used:
  num_threads_chrono = 1
  num_threads_collision = 1
  num_threads_eigen = 1

Note that a derived class may ignore some or all of these settings.

Reimplemented in chrono::ChSystemMulticore.

◆ SetSleepingAllowed()

void chrono::ChSystem::SetSleepingAllowed ( bool  ms)
inline

Turn on this feature to let the system put to sleep the bodies whose motion has almost come to a rest.

This feature will allow faster simulation of large scenarios for real-time purposes, but it will affect the precision! This functionality can be turned off selectively for specific ChBodies.

◆ SetSolver()

void chrono::ChSystem::SetSolver ( std::shared_ptr< ChSolver newsolver)
virtual

Attach a solver (derived from ChSolver) for use by this system.

  • Suggested solver for speed, but lower precision: PSOR
  • Suggested solver for higher precision: BARZILAIBORWEIN or APGD
  • For problems that involve a stiffness matrix: GMRES, MINRES

◆ SetSolverType()

void chrono::ChSystem::SetSolverType ( ChSolver::Type  type)

Choose the solver type, to be used for the simultaneous solution of the constraints in dynamical simulations (as well as in kinematics, statics, etc.) Notes:

  • This function is a shortcut, internally equivalent to a call to SetSolver().
  • Only a subset of available Chrono solvers can be set through this mechanism.
  • Prefer explicitly creating a solver, setting solver parameters, and then attaching the solver with SetSolver.
Deprecated:
This function does not support all available Chrono solvers. Prefer using SetSolver.

◆ SetTimestepperType()

void chrono::ChSystem::SetTimestepperType ( ChTimestepper::Type  type)

Set the method for time integration (time stepper type).

  • Suggested for fast dynamics with hard (NSC) contacts: EULER_IMPLICIT_LINEARIZED
  • Suggested for fast dynamics with hard (NSC) contacts and low inter-penetration: EULER_IMPLICIT_PROJECTED
  • Suggested for finite element smooth dynamics: HHT, EULER_IMPLICIT_LINEARIZED For full access to a time stepper's settings, use SetTimestepper()

◆ Setup()

void chrono::ChSystem::Setup ( )
virtual

Counts the number of bodies and links.

Computes the offsets of object states in the global state. Assumes that offset_x, offset_w, and offset_L are already set as starting point for offsetting all the contained sub objects.

Reimplemented in chrono::ChSystemMulticoreSMC, and chrono::ChSystemMulticore.

◆ ShowHierarchy()

void chrono::ChSystem::ShowHierarchy ( std::ostream &  m_file,
int  level = 0 
) const
inline

Write the hierarchy of contained bodies, markers, etc.

in ASCII readable form, mostly for debugging purposes. Level is the tab spacing at the left.

◆ StateIncrementX()

void chrono::ChSystem::StateIncrementX ( ChState x_new,
const ChState x,
const ChStateDelta Dx 
)
overridevirtual

Perform x_new = x + dx, for x in Y = {x, dx/dt}.


It takes care of the fact that x has quaternions, dx has angular vel etc. NOTE: the system is not updated automatically after the state increment, so one might need to call StateScatter() if needed.

Parameters
x_newresulting x_new = x + Dx
xinitial state x
Dxstate increment Dx

Reimplemented from chrono::ChIntegrableIIorder.

◆ StateSolveCorrection()

bool chrono::ChSystem::StateSolveCorrection ( ChStateDelta Dv,
ChVectorDynamic<> &  DL,
const ChVectorDynamic<> &  R,
const ChVectorDynamic<> &  Qc,
const double  c_a,
const double  c_v,
const double  c_x,
const ChState x,
const ChStateDelta v,
const double  T,
bool  force_state_scatter,
bool  full_update,
bool  force_setup 
)
overridevirtual

Assuming a DAE of the form.

      M*a = F(x,v,t) + Cq'*L
      C(x,t) = 0

this function computes the solution of the change Du (in a or v or x) for a Newton iteration within an implicit integration scheme.

 | Du| = [ G   Cq' ]^-1 * | R |
 |-DL|   [ Cq  0   ]      |-Qc|

for residual R and G = [ c_a*M + c_v*dF/dv + c_x*dF/dx ].
This function returns true if successful and false otherwise.

Parameters
Dvresult: computed Dv
DLresult: computed lagrangian multipliers. Note the sign in system above.
Rthe R residual
Qcthe Qc residual. Note the sign in system above.
c_athe factor in c_a*M
c_vthe factor in c_v*dF/dv
c_xthe factor in c_x*dF/dv
xcurrent state, x part
vcurrent state, v part
Tcurrent time T
force_state_scatterif false, x and v are not scattered to the system
full_updateif true, perform a full update during scatter
force_setupif true, call the solver's Setup() function

Reimplemented from chrono::ChIntegrableIIorder.

◆ WriteSystemMatrices()

void chrono::ChSystem::WriteSystemMatrices ( bool  save_M,
bool  save_K,
bool  save_R,
bool  save_Cq,
const std::string &  path,
bool  one_indexed = true 
)

Write the mass (M), damping (R), stiffness (K), and constraint Jacobian (Cq) matrices at current configuration.

These can be used for linearized motion, modal analysis, buckling analysis, etc. The sparse matrices are saved in COO format in 'path' folder according to the naming: solve_M.dat solve_K.dat solve_R.dat, and solve_Cq.dat. By default, uses 1-based indices (as in Matlab).

Member Data Documentation

◆ visual_system

ChVisualSystem* chrono::ChSystem::visual_system
protected

material composition strategy

run-time visualization engine


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