chrono::fea::ChBeamSectionCosserat Class Reference

## Description

Base class for properties of beam sections of Cosserat type (with shear too).

A beam section can be shared between multiple beams. A beam section contains the models for elasticity, plasticity, damping, etc.

#include <ChBeamSectionCosserat.h>

Inheritance diagram for chrono::fea::ChBeamSectionCosserat:
Collaboration diagram for chrono::fea::ChBeamSectionCosserat:

## Public Member Functions

ChBeamSectionCosserat (std::shared_ptr< ChElasticityCosserat > melasticity, std::shared_ptr< ChPlasticityCosserat > mplasticity=nullptr, std::shared_ptr< ChDampingCosserat > mdamping=nullptr)

virtual void ComputeStress (ChVector<> &stress_n, ChVector<> &stress_m, const ChVector<> &strain_e, const ChVector<> &strain_k, ChBeamMaterialInternalData *mdata_new=nullptr, const ChBeamMaterialInternalData *mdata=nullptr)
Compute the generalized cut force and cut torque, given the actual generalized section strain expressed as deformation vector e and curvature k, that is: {F,M}=f({e,k}), and given the actual material state required for plasticity if any (but if mdata=nullptr, computes only the elastic force). More...

virtual void ComputeStiffnessMatrix (ChMatrixDynamic<> &K, const ChVector<> &strain_e, const ChVector<> &strain_k, const ChBeamMaterialInternalData *mdata=nullptr)
Compute the 6x6 tangent material stiffness matrix [Km] =d/d at a given strain state, and at given internal data state (if mdata=nullptr, computes only the elastic tangent stiffenss, regardless of plasticity). More...

void SetElasticity (std::shared_ptr< ChElasticityCosserat > melasticity)
Set the elasticity model for this section. More...

std::shared_ptr< ChElasticityCosseratGetElasticity ()
Get the elasticity model for this section. More...

void SetPlasticity (std::shared_ptr< ChPlasticityCosserat > mplasticity)
Set the plasticity model for this section. More...

std::shared_ptr< ChPlasticityCosseratGetPlasticity ()
Get the elasticity model for this section, if any. More...

void SetDamping (std::shared_ptr< ChDampingCosserat > mdamping)
Set the damping model for this section. More...

std::shared_ptr< ChDampingCosseratGetDamping ()
Get the damping model for this section. More...

virtual void SetAsRectangularSection (double width_y, double width_z)
Shortcut: set elastic and plastic constants at once, given the y and z widths of the beam assumed with rectangular shape. More...

virtual void SetAsCircularSection (double diameter)
Shortcut: set elastic and plastic constants at once, given the diameter of the beam assumed with circular shape. More...

Public Member Functions inherited from chrono::fea::ChBeamSectionProperties
void SetDrawThickness (double thickness_y, double thickness_z)
Sets the rectangular thickness of the beam on y and z directions, only for drawing/rendering purposes (these thickness values do NOT have any meaning at a physical level, use SetAsRectangularSection()

double GetDrawThicknessY ()

double GetDrawThicknessZ ()

bool IsCircular ()
Tells if the section must be drawn as a circular section instead than default rectangular.

void SetCircular (bool ic)
Set if the section must be drawn as a circular section instead than default rectangular.

Sets the radius of the beam if in 'circular section' draw mode, only for drawing/rendering purposes (this radius value do NOT have any meaning at a physical level, use ChBeamSectionBasic::SetAsCircularSection()

void SetArea (const double ma)
Set the cross sectional area A of the beam (m^2)

double GetArea () const

void SetDensity (double md)
Set the density of the beam (kg/m^3)

double GetDensity () const

## Additional Inherited Members

Public Attributes inherited from chrono::fea::ChBeamSectionProperties
double y_drawsize

double z_drawsize

bool is_circular

double Area

double density

## Constructor & Destructor Documentation

 chrono::fea::ChBeamSectionCosserat::ChBeamSectionCosserat ( std::shared_ptr< ChElasticityCosserat > melasticity, std::shared_ptr< ChPlasticityCosserat > mplasticity = nullptr, std::shared_ptr< ChDampingCosserat > mdamping = nullptr )
Parameters
 mplasticity the elasticity model for this section, ex.ChElasticityCosseratSimple mdamping the plasticity model for this section, if any the damping model for this section, if any

## Member Function Documentation

 virtual void chrono::fea::ChBeamSectionCosserat::ComputeStiffnessMatrix ( ChMatrixDynamic<> & K, const ChVector<> & strain_e, const ChVector<> & strain_k, const ChBeamMaterialInternalData * mdata = nullptr )
virtual

Compute the 6x6 tangent material stiffness matrix [Km] =d/d at a given strain state, and at given internal data state (if mdata=nullptr, computes only the elastic tangent stiffenss, regardless of plasticity).

Parameters
 K returns the 6x6 stiffness matrix strain_e strain (deformation part): x= elongation, y and z are shear strain_k strain (curvature part), x= torsion, y and z are line curvatures mdata material internal variables, at this point, if any, including {p_strain_e, p_strain_k, p_strain_acc}
 virtual void chrono::fea::ChBeamSectionCosserat::ComputeStress ( ChVector<> & stress_n, ChVector<> & stress_m, const ChVector<> & strain_e, const ChVector<> & strain_k, ChBeamMaterialInternalData * mdata_new = nullptr, const ChBeamMaterialInternalData * mdata = nullptr )
virtual

Compute the generalized cut force and cut torque, given the actual generalized section strain expressed as deformation vector e and curvature k, that is: {F,M}=f({e,k}), and given the actual material state required for plasticity if any (but if mdata=nullptr, computes only the elastic force).

If there is plasticity, the stress is clamped by automatically performing an implicit return mapping. In sake of generality, if possible this is the function that should be used by beam finite elements to compute internal forces, ex.by some Gauss quadrature.

Parameters
 stress_n return the stress (generalized force F), x component = traction along beam stress_m return the stress (generalized torque M), x component = torsion torque along beam strain_e strain (deformation part e): x= elongation, y and z are shear strain_k strain (curvature part k), x= torsion, y and z are line curvatures mdata_new return updated material internal variables, at this point, including {p_strain_e, p_strain_k, p_strain_acc} mdata current material internal variables, at this point, including {p_strain_e, p_strain_k, p_strain_acc}
 std::shared_ptr chrono::fea::ChBeamSectionCosserat::GetDamping ( )

Get the damping model for this section.

By default no damping.

 std::shared_ptr chrono::fea::ChBeamSectionCosserat::GetElasticity ( )

Get the elasticity model for this section.

Use this function to access parameters such as stiffness, Young modulus, etc. By default it uses a simple centered linear elastic model.

 std::shared_ptr chrono::fea::ChBeamSectionCosserat::GetPlasticity ( )

Get the elasticity model for this section, if any.

Use this function to access parameters such as yeld limit, etc.

 virtual void chrono::fea::ChBeamSectionCosserat::SetAsCircularSection ( double diameter )
virtual

Shortcut: set elastic and plastic constants at once, given the diameter of the beam assumed with circular shape.

Implements chrono::fea::ChBeamSectionProperties.

 virtual void chrono::fea::ChBeamSectionCosserat::SetAsRectangularSection ( double width_y, double width_z )
virtual

Shortcut: set elastic and plastic constants at once, given the y and z widths of the beam assumed with rectangular shape.

Implements chrono::fea::ChBeamSectionProperties.

 void chrono::fea::ChBeamSectionCosserat::SetDamping ( std::shared_ptr< ChDampingCosserat > mdamping )

Set the damping model for this section.

By default no damping.

 void chrono::fea::ChBeamSectionCosserat::SetElasticity ( std::shared_ptr< ChElasticityCosserat > melasticity )

Set the elasticity model for this section.

By default it uses a simple centered linear elastic model, but you can set more complex models.

 void chrono::fea::ChBeamSectionCosserat::SetPlasticity ( std::shared_ptr< ChPlasticityCosserat > mplasticity )

Set the plasticity model for this section.

This is independent from the elasticity model. Note that by default there is no plasticity model, so by default plasticity never happens.