Description

Performs a step of Newmark constrained implicit for II order DAE systems.

See Negrut et al. 2007.

#include <ChTimestepper.h>

Inheritance diagram for chrono::ChTimestepperNewmark:

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Collaboration diagram for chrono::ChTimestepperNewmark:

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Public Member Functions
	ChTimestepperNewmark (ChIntegrableIIorder *intgr=nullptr)
	Constructors (default empty)

virtual Type	GetType () const override
	Return type of the integration method. More...

void	SetGammaBeta (double mgamma, double mbeta)
	Set the numerical damping parameter gamma and the beta parameter. More...

double	GetGamma ()

double	GetBeta ()

void	SetModifiedNewton (bool val)
	Enable/disable modified Newton. More...

virtual void	Advance (const double dt) override
	Performs an integration timestep. More...

virtual void	ArchiveOUT (ChArchiveOut &archive) override
	Method to allow serialization of transient data to archives.

virtual void	ArchiveIN (ChArchiveIn &archive) override
	Method to allow de-serialization of transient data from archives.

Public Member Functions inherited from chrono::ChTimestepperIIorder
	ChTimestepperIIorder (ChIntegrableIIorder *intgr=nullptr)
	Constructor.

virtual	~ChTimestepperIIorder ()
	Destructor.

virtual ChState &	get_X ()
	Access the state, position part, at current time.

virtual ChStateDelta &	get_V ()
	Access the state, speed part, at current time.

virtual ChStateDelta &	get_A ()
	Access the acceleration, at current time.

virtual void	SetIntegrable (ChIntegrableIIorder *intgr)
	Set the integrable object.

Public Member Functions inherited from chrono::ChTimestepper
	ChTimestepper (ChIntegrable *intgr=nullptr)
	Constructor.

virtual	~ChTimestepper ()
	Destructor.

virtual ChVectorDynamic &	get_L ()
	Access the lagrangian multipliers, if any.

virtual void	SetIntegrable (ChIntegrable *intgr)
	Set the integrable object.

ChIntegrable *	GetIntegrable ()
	Get the integrable object.

virtual double	GetTime () const
	Get the current time.

virtual void	SetTime (double mt)
	Set the current time.

void	SetVerbose (bool verb)
	Turn on/off logging of messages.

void	SetQcDoClamp (bool dc)
	Turn on/off clamping on the Qcterm.

void	SetQcClamping (double cl)
	Turn on/off clamping on the Qcterm.

Public Member Functions inherited from chrono::ChImplicitIterativeTimestepper
void	SetMaxiters (int iters)
	Set the max number of iterations using the Newton Raphson procedure.

double	GetMaxiters ()
	Get the max number of iterations using the Newton Raphson procedure.

void	SetRelTolerance (double rel_tol)
	Set the relative tolerance. More...

void	SetAbsTolerances (double abs_tolS, double abs_tolL)
	Set the absolute tolerances. More...

void	SetAbsTolerances (double abs_tol)
	Set the absolute tolerances. More...

int	GetNumIterations () const
	Return the number of iterations.

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

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

Additional Inherited Members
Public Types inherited from chrono::ChTimestepper
enum	Type { EULER_IMPLICIT_LINEARIZED = 0, EULER_IMPLICIT_PROJECTED = 1, EULER_IMPLICIT = 2, TRAPEZOIDAL = 3, TRAPEZOIDAL_LINEARIZED = 4, HHT = 5, HEUN = 6, RUNGEKUTTA45 = 7, EULER_EXPLICIT = 8, LEAPFROG = 9, NEWMARK = 10, CUSTOM = 20 }
	Available methods for time integration (time steppers).

Protected Attributes inherited from chrono::ChTimestepperIIorder
ChState	X

ChStateDelta	V

ChStateDelta	A

Protected Attributes inherited from chrono::ChTimestepper
ChIntegrable *	integrable

double	T

ChVectorDynamic	L

bool	verbose

bool	Qc_do_clamp

double	Qc_clamping

Protected Attributes inherited from chrono::ChImplicitIterativeTimestepper
int	maxiters
	maximum number of iterations

double	reltol
	relative tolerance

double	abstolS
	absolute tolerance (states)

double	abstolL
	absolute tolerance (Lagrange multipliers)

int	numiters
	number of iterations

int	numsetups
	number of calls to the solver's Setup function

int	numsolves
	number of calls to the solver's Solve function

Member Function Documentation

◆ Advance()

void chrono::ChTimestepperNewmark::Advance ( const double dt )

overridevirtual

Performs an integration timestep.

Parameters

dt	timestep to advance

Implements chrono::ChTimestepper.

◆ GetType()

virtual Type chrono::ChTimestepperNewmark::GetType ( ) const

inlineoverridevirtual

Return type of the integration method.

Default is CUSTOM. Derived classes should override this function.

Reimplemented from chrono::ChTimestepper.

◆ SetGammaBeta()

void chrono::ChTimestepperNewmark::SetGammaBeta	(	double	mgamma,
		double	mbeta
	)

Set the numerical damping parameter gamma and the beta parameter.

Gamma: in the [1/2, 1] interval. For gamma = 1/2, no numerical damping For gamma > 1/2, more damping Beta: in the [0, 1] interval. For beta = 1/4, gamma = 1/2 -> constant acceleration method For beta = 1/6, gamma = 1/2 -> linear acceleration method Method is second order accurate only for gamma = 1/2

◆ SetModifiedNewton()

void chrono::ChTimestepperNewmark::SetModifiedNewton ( bool val )

inline

Enable/disable modified Newton.

If enabled, the Newton matrix is evaluated, assembled, and factorized only once per step. If disabled, the Newton matrix is evaluated at every iteration of the nonlinear solver. Modified Newton iteration is enabled by default.

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

/builds/uwsbel/chrono/src/chrono/timestepper/ChTimestepper.h
/builds/uwsbel/chrono/src/chrono/timestepper/ChTimestepper.cpp