Description

Class for linear damping (Newton damping in lagrangian solid, as S=D:E_dot where E_dot is the time derivative of Green Lagrange strain and D is a constant tensor build from viscosity coefficients, or more in detail: S = lambda tr(E_dot) I + 2μ E_dot ).

This is a bit different from the ChMaterial3DStressViscoNewton, which provides damping forces proportional to the spatial velocity, as in CFD fluids. But this is faster to compute. It is assumed to be used in parallel with some elastic stress model like ChMaterial3DStressStVenant. If used alone, it provides a fluid-like viscous damping.

#include <ChMaterial3DStressViscoLinear.h>

Inheritance diagram for chrono::fea::ChMaterial3DStressViscoLinear:

[legend]

Collaboration diagram for chrono::fea::ChMaterial3DStressViscoLinear:

[legend]

Public Member Functions
virtual void	SetDeviatoricDamping (double mdamp)
	Set the damping for the deviatoric effect. More...

virtual double	GetDeviatoricDamping () const

virtual void	SetVolumetricDamping (double mdamp)
	Set the damping for the volumetric effect. More...

virtual double	GetVolumetricDamping () const

virtual void	ComputeStress (ChStressTensor<> &S_stress, const ChMatrix33d &F, const ChMatrix33d l, ChFieldData data_per_point, ChElementData *data_per_element) override
	Compute elastic stress from spatial velocity gradient "l". More...

virtual void	ComputeTangentModulus (ChMatrixNM< double, 6, 6 > &C, ChMatrixNM< double, 6, 6 > D, const ChMatrix33d &F_def, const ChMatrix33d l, ChFieldData data_per_point, ChElementData data_per_element) override
	Computes the tangent modulus. More...

virtual bool	IsSpatialVelocityGradientNeeded () const
	This material need info on the spatial velocity gradient l=\nabla_x v.

Public Member Functions inherited from chrono::fea::ChMaterial3DStress
virtual void	ComputeUpdateEndStep (ChFieldData data_per_point, ChElementData data_per_element, const double time)
	Update your own auxiliary data, if any, at the end of time step (ex for plasticity). More...

Public Member Functions inherited from chrono::fea::ChMaterial3DDensity
	ChMaterial3DDensity (double density=1000)

virtual void	SetDensity (double density)
	Set the density of the material, in kg/m^2.

virtual double	GetDensity () const
	Get the density of the material, in kg/m^2.

Public Member Functions inherited from chrono::fea::ChMaterial
virtual std::unique_ptr< ChFieldData >	CreateMaterialPointData () const
	Implement this if the material needs custom data per material point, returning a std::make_unique<ChFieldDataCustom>() where ChFieldDataCustom is your custom class with aditional states/properties per-point.

Additional Inherited Members
Protected Attributes inherited from chrono::fea::ChMaterial3DDensity
double	m_density

Member Function Documentation

◆ ComputeStress()

virtual void chrono::fea::ChMaterial3DStressViscoLinear::ComputeStress	(	ChStressTensor<> &	S_stress,
		const ChMatrix33d &	F,
		const ChMatrix33d *	l,
		ChFieldData *	data_per_point,
		ChElementData *	data_per_element
	)

inlineoverridevirtual

Compute elastic stress from spatial velocity gradient "l".

Parameters

S_stress	output stress, PK2
F	current deformation gradient tensor
l	current spatial velocity gradient (might be nullptr if IsSpatialVelocityGradientNeeded() is false)
data_per_point	pointer to auxiliary data (ex states), if any, per quadrature point
data_per_element	pointer to auxiliary data (ex states), if any, per element

Implements chrono::fea::ChMaterial3DStress.

◆ ComputeTangentModulus()

virtual void chrono::fea::ChMaterial3DStressViscoLinear::ComputeTangentModulus	(	ChMatrixNM< double, 6, 6 > &	C,
		ChMatrixNM< double, 6, 6 > *	D,
		const ChMatrix33d &	F_def,
		const ChMatrix33d *	l,
		ChFieldData *	data_per_point,
		ChElementData *	data_per_element
	)

inlineoverridevirtual

Computes the tangent modulus.

Parameters

C	output C tangent modulus, as dS=C*dE
D	output D tangent modulus, as dS=C*d(E_dot) (maybe nullptr if IsSpatialVelocityGradientNeeded() is false)
F_def	current deformation gradient tensor
l	current spatial velocity gradient (might be nullptr if IsSpatialVelocityGradientNeeded() is false)
data_per_point	pointer to auxiliary data (ex states), if any, per quadrature point
data_per_element	pointer to auxiliary data (ex states), if any, per element

Implements chrono::fea::ChMaterial3DStress.

◆ SetDeviatoricDamping()

virtual void chrono::fea::ChMaterial3DStressViscoLinear::SetDeviatoricDamping ( double mdamp )

inlinevirtual

Set the damping for the deviatoric effect.

This corresponds to the viscous damping μ in Newtonian fluids.

◆ SetVolumetricDamping()

virtual void chrono::fea::ChMaterial3DStressViscoLinear::SetVolumetricDamping ( double mdamp )

inlinevirtual

Set the damping for the volumetric effect.

If the material is incompressible or nearly incompressible, this term has no effect.

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

/builds/uwsbel/chrono/src/chrono/fea/multiphysics/ChMaterial3DStressViscoLinear.h