A contact model based on the Hertz-Mindlin theory of elastic-plastic contact. More...

#include <model_hertz_mindlin.hpp>

Inheritance diagram for netdem::HertzMindlin:

Public Member Functions
	HertzMindlin ()

	HertzMindlin (double E_eq, double kt, double mu, double beta)
	Construct a HertzMindlin object with the specified parameters.

nlohmann::json	PackJson () override
	Pack object data into a JSON object for serialization.

void	InitFromJson (nlohmann::json const &js) override
	Initialize object data from a JSON object.

void	SetProperty (nlohmann::json const &js) override
	Set a property of the object from a JSON object.

void	SetProperty (std::string const &name, double value) override
	Set a named property of the object to a given value.

ContactModel *	Clone () const override
	Create a deep copy of the object.

void	EvaluateForces (ContactForces const cnt_forces, CollisionGeometries &cnt_geoms, ContactPP const cnt, double dt) const override
	Compute the force and moment on a particle-particle contact point.

void	EvaluateForces (ContactForces const cnt_forces, CollisionGeometries &cnt_geoms, ContactPW const cnt, double dt) const override
	Compute the force and moment on a particle-wall contact point.

void	Print () const override
	Print information about the current state of the object to the console.

Public Member Functions inherited from netdem::ContactModel
virtual void	EvaluateForces (ContactForces const cnt_forces, BondGeometries &cnt_geoms, ContactPP const cnt, double dt) const
	Calculate the contact forces and moments due to this model.

virtual void	EvaluateForces (ContactForces const cnt_forces, BondGeometries &cnt_geoms, ContactPW const cnt, double dt) const
	Calculate the contact forces and moments due to this model.

virtual	~ContactModel ()

Public Attributes
double	E_eq {2.0e7}

double	kt {1.0e6}

double	beta {0.7}

double	mu {0.5}

Public Attributes inherited from netdem::ContactModel
int	id {0}

std::string	label {"default"}

int	model_type {0}

std::string	model_name {"contact_model"}

Additional Inherited Members
Public Types inherited from netdem::ContactModel
enum	Type { none , linear_spring , hertz_mindlin , volume_based , parallel_bond }

Detailed Description

A contact model based on the Hertz-Mindlin theory of elastic-plastic contact.

This class provides a set of methods and member variables for computing contact forces and moments between particles and walls or other particles, based on the Hertz-Mindlin theory of elastic-plastic contact. The model assumes that both contacting bodies are elastic, but that they can deform plastically under high pressures. The contact force is computed based on the overlap between the two bodies at a given contact point, as well as the elastic properties of the bodies (represented by the normal and tangential stiffnesses kn and kt) and the frictional properties (represented by the coefficient of friction mu).

Examples: 97_triaixal_comp_sphere_geom.cpp.

Constructor & Destructor Documentation

◆ HertzMindlin() [1/2]

netdem::HertzMindlin::HertzMindlin ( )

A default constructor for this class (sets all parameters to their default values).

◆ HertzMindlin() [2/2]

netdem::HertzMindlin::HertzMindlin	(	double	E_eq,
		double	kt,
		double	mu,
		double	beta )

Construct a HertzMindlin object with the specified parameters.

This constructor creates a HertzMindlin object with the specified values for the normal and tangential stiffnesses, the damping ratio, and the coefficient of friction.

Parameters

E_eq	The equivalent Young's modulus of the interacting bodies.
kt	The tangential stiffness of the interacting bodies.
mu	The coefficient of friction between the interacting bodies.
beta	The damping ratio used in the model.

Member Function Documentation

◆ Clone()

ContactModel * netdem::HertzMindlin::Clone ( ) const

overridevirtual

Create a deep copy of the object.

This method creates a new HertzMindlin object with the same parameter values as the current object, and returns a pointer to the new object.

Returns: A pointer to a new HertzMindlin object with identical parameter values.

Reimplemented from netdem::ContactModel.

◆ EvaluateForces() [1/2]

void netdem::HertzMindlin::EvaluateForces	(	ContactForces *const	cnt_forces,
		CollisionGeometries &	cnt_geoms,
		ContactPP *const	cnt,
		double	dt ) const

overridevirtual

Compute the force and moment on a particle-particle contact point.

This method computes the normal and tangential forces and moments exerted on a particle-particle contact point, based on the current state of the two particles and the parameters of the Hertz-Mindlin model. The resulting forces and moments are added to the ContactForces object passed in to the method.

Parameters

cnt_forces	A pointer to the ContactForces object tracking all contact forces and moments.
cnt_geoms	A reference to the CollisionGeometries object containing information about the colliding objects.
cnt	A pointer to the ContactPP object representing the particle-particle contact.
dt	The time step used in the simulation.

Reimplemented from netdem::ContactModel.

◆ EvaluateForces() [2/2]

void netdem::HertzMindlin::EvaluateForces	(	ContactForces *const	cnt_forces,
		CollisionGeometries &	cnt_geoms,
		ContactPW *const	cnt,
		double	dt ) const

overridevirtual

Compute the force and moment on a particle-wall contact point.

This method computes the normal and tangential forces and moments exerted on a particle-wall contact point, based on the current state of the particle and the parameters of the Hertz-Mindlin model. The resulting forces and moments are added to the ContactForces object passed in to the method.

Parameters

cnt_forces	A pointer to the ContactForces object tracking all contact forces and moments.
cnt_geoms	A reference to the CollisionGeometries object containing information about the colliding objects.
cnt	A pointer to the ContactPW object representing the particle-wall contact.
dt	The time step used in the simulation.

Reimplemented from netdem::ContactModel.

◆ InitFromJson()

void netdem::HertzMindlin::InitFromJson ( nlohmann::json const & js )

overridevirtual

Initialize object data from a JSON object.

This method initializes the state of the HertzMindlin object from a JSON object, as created by the PackJson() method. It is used during deserialization of saved simulation states.

Parameters

js	A JSON object representing the desired state of the HertzMindlin object.

Reimplemented from netdem::ContactModel.

◆ PackJson()

nlohmann::json netdem::HertzMindlin::PackJson ( )

overridevirtual

Pack object data into a JSON object for serialization.

This method packs the current state of the HertzMindlin object into a JSON object, for use in serialization and deserialization.

Returns: A JSON object representing the current state of the HertzMindlin object.

Reimplemented from netdem::ContactModel.

◆ Print()

void netdem::HertzMindlin::Print ( ) const

overridevirtual

Print information about the current state of the object to the console.

This method prints information about the current parameter values of the HertzMindlin object to the console, for debugging and analysis purposes.

Reimplemented from netdem::ContactModel.

◆ SetProperty() [1/2]

void netdem::HertzMindlin::SetProperty ( nlohmann::json const & js )

overridevirtual

Set a property of the object from a JSON object.

This method sets a named property of the HertzMindlin object from a JSON object. If the named property does not exist, this method throws an exception.

Parameters

js	A JSON object containing the desired new value for the named property.

Reimplemented from netdem::ContactModel.

◆ SetProperty() [2/2]

void netdem::HertzMindlin::SetProperty	(	std::string const &	name,
		double	value )

overridevirtual

Set a named property of the object to a given value.

This method sets a named property of the HertzMindlin object to a given value. If the named property does not exist, this method throws an exception.

Parameters

name	The name of the property to set.
value	The desired new value for the named property.

Reimplemented from netdem::ContactModel.

Member Data Documentation

◆ beta

double netdem::HertzMindlin::beta {0.7}

The damping ratio used in the model (defaults to 0.7).

◆ E_eq

double netdem::HertzMindlin::E_eq {2.0e7}

The equivalent Young's modulus of the interacting bodies.

◆ kt

double netdem::HertzMindlin::kt {1.0e6}

The tangential stiffness of the interacting bodies.

◆ mu

double netdem::HertzMindlin::mu {0.5}

The coefficient of friction between the interacting bodies.

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

/Users/lzhshou/Documents/Research/myProjects/apaam/repo/netdem/src/dem/model_hertz_mindlin.hpp
/Users/lzhshou/Documents/Research/myProjects/apaam/repo/netdem/src/dem/model_hertz_mindlin.cpp

Public Member Functions

Public Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ HertzMindlin() [1/2]

◆ HertzMindlin() [2/2]

Member Function Documentation

◆ Clone()

◆ EvaluateForces() [1/2]

◆ EvaluateForces() [2/2]

◆ InitFromJson()

◆ PackJson()

◆ Print()

◆ SetProperty() [1/2]

◆ SetProperty() [2/2]

Member Data Documentation

◆ beta

◆ E_eq

◆ kt

◆ mu