mohrcoulomb Class Reference

#include <mohrc.h>

Public Member Functions
void	changeparam (atsel &atm, vector &val)
	function changes material parameters (used in stochastic calculations)
long	checkpsig (vector &psig)
	checks type of singularity region and returns singularity indicator
long	checkzeropsig (vector &psig)
	checks for index of out of plane principal stress in case plane stress problem
long	cutting_plane (long ipp, double &gamma, vector &epsn, vector &epsp, vector &q, long ni, double err)
	cutting plane algorithm at principal stresses
void	derplaspotsigma (vector &dgds)
void	deryieldfsigma (vector &dfds)
void	dfdsigma (long *stat, long mu, matrix &dfds)
void	dgdsigma (long *stat, long mu, matrix &dgds)
double	give_consparam (long ipp, long ido)
	returns consistency parameter
void	giveirrstrains (long ipp, long ido, vector &epsp)
	returns plastic strains
void	matstiff (matrix &d, long ipp, long ido)
	stiffness matrix for given intgration point
void	mc_msurf_cp (long ipp, double &gamma, vector &epsn, vector &epsp, vector &q, long mu, long ni, double err)
	multisurface cutting plane algorithm at principal stresses
	mohrcoulomb (void)
void	nlstresses (long ipp, long ido)
	computes stresses at the given integration point
void	nonloc_nlstresses (long ipp, long ido)
	computes stresses at the given integration point from the nonlocal strain values
void	pelmatstiff (long ipp, matrix &d, double e, double nu)
	elastic stiffness matrix for elastic isotropic material computed at principal stress directions
void	plasmodscalar (long ipp, vector &q, long mu, matrix &hcpm)
	returns hardening contribution for multisurface cutting plane method
double	plasmodscalar (long ipp, vector &q)
	returns hardening contribution for cutting_plane method
void	read (XFILE *in)
void	tangentstiff (matrix &d, matrix &td, long ipp, long ido)
	tangent stiffness matrix for given integration point
void	updateq (long ipp, vector &epsp, vector &q)
	updates hardening parameters
void	updateval (long ipp, long im, long ido)
	updates values of the integration point eqother array with the new reached
void	yieldfunction (vector &psig, long mu, vector &f)
void	yieldfunction (vector &psig, long mu, long *stat, vector &f)
double	yieldfunction (vector &psig)
	~mohrcoulomb (void)
Public Attributes
double	c
	cohesion
double	phi
	friction angle
double	psi
	dilatation
strretalg	sra
	stress return algorithm

Detailed Description

The class defines nonassociated plastic material model with Mohr-Coulomb yield criterion. Single-surface stress return cutting plane algorithm is used for detection of active yield surfaces and if it is necessary, the multi-surface cutting plane algorithm is used.

Created by Tomas Koudelka,

Definition at line 19 of file mohrc.h.

Constructor & Destructor Documentation

mohrcoulomb ( void )

The constructor inializes attributes to zero values.

Created by Tomas Koudelka,

Definition at line 26 of file mohrc.cpp.

References c, phi, and psi.

~mohrcoulomb ( void )

The destructor is defined only for the formal purposes.

Created by Tomas Koudelka,

Definition at line 38 of file mohrc.cpp.

Member Function Documentation

void changeparam	(	atsel &	atm,
		vector &	val
	)

function changes material parameters (used in stochastic calculations)

The function changes material parameters for stochastic analysis.

Parameters:

	atm	- selected material parameters (parameters which are changed)
	val	- array containing new values of parameters

Returns:: The function does not return anything.

Created by Tomas Koudelka,

Definition at line 1076 of file mohrc.cpp.

References atsel::atrib, c, atsel::num, phi, print_err(), and psi.

long checkpsig ( vector & psig )

checks type of singularity region and returns singularity indicator

Function checks ordering of principal stresses and vertex singularity.

Parameters:

psig

- principal stress vector sorted in this way psig[0] < psig[1] < psig[2]

Return values:

	12	- in case that the psig[0] < psig[1] condition is not statisfied
	23	- in case that the psig[1] < psig[2] condition is not statisfied
	1	- in case that the vertex singularity occurs i.e. tensile strength is exceeded
	0	- in other cases

Created by Tomas Koudelka, 4.11.2003

Definition at line 562 of file mohrc.cpp.

References c, and phi.

Referenced by cutting_plane().

long checkzeropsig ( vector & psig )

checks for index of out of plane principal stress in case plane stress problem

Function checks ordering of principal stresses and vertex singularity.

Parameters:

psig

- principal stress vector sorted in this way psig[0] < psig[1] < psig[2]

Returns:: Function returns index of zero psig.

Created by Tomas Koudelka,4.11.2003

Definition at line 596 of file mohrc.cpp.

Referenced by cutting_plane(), and mc_msurf_cp().

long cutting_plane	(	long	ipp,
		double &	gamma,
		vector &	epsn,
		vector &	epsp,
		vector &	q,
		long	ni,
		double	err
	)

cutting plane algorithm at principal stresses

Function returns stresses on sufrace of plasticity cutting plane method in principal stresses is used

Parameters gamma, epsp and q will be replaced by new values

Parameters:

	ipp	- integration point pointer
	gamma	- consistency parameter (input/output)
	epsn	- total strain components
	epsp	- plastic strain components (input/output)
	q	- hardening parameters (input/output)
	ni	- maximum number of iterations
	err	- required error

Returns:: Function returns indicator of active yield surfaces in case detection of the singularity or zero in case of successfull stress return. In addition, the function updates parameters gamma, epsp and q.

Created by Tomas Koudelka, 4.8.2001

Definition at line 405 of file mohrc.cpp.

References addv(), checkpsig(), checkzeropsig(), copyv(), derplaspotsigma(), deryieldfsigma(), elisomat, mechmat::elmatstiff(), f, fillcol(), fillrow(), intpoints::gemid(), mechmat::give_actual_nu(), mechmat::give_actual_ym(), glmatrixtransf(), mechmat::ip, lgmatrixtransf(), limit, Mm, Mp, mxv(), vector::n, nijac, pelmatstiff(), planestrain, planestress, plasmodscalar(), princ_val(), print_err(), scprd(), intpoints::ssst, mechmat::storestress(), strain, stress, subv(), tensor_vector(), intpoints::tm, updateq(), vector_tensor(), yieldfunction(), and probdesc::zero.

Referenced by nlstresses(), and nonloc_nlstresses().

void derplaspotsigma ( vector & dgds )

derivatives of plastic potential function with respect of principal stresses for standard stress ordering sig1 < sig2 < sig3

The function computes derivatives of plastic potential function with respect of the principal stresses vector.

Parameters:

dgds

- vector for resulting derivatives (output)

Returns:: The function returns vector of required derivatives.

Created by Tomas Koudelka, 10.11.2003

Definition at line 119 of file mohrc.cpp.

References psi.

Referenced by cutting_plane().

void deryieldfsigma ( vector & dfds )

derivatives of yield function with respect of principal stresses for standard stress ordering sig1 < sig2 < sig3

The function computes derivatives of yield function with respect of the principal stresses vector

Parameters:

dfds

- vector for resulting derivatives (output)

Returns:: The function returns vector of required derivatives.

Created by Tomas Koudelka, 10.11.2003

Definition at line 99 of file mohrc.cpp.

References phi.

Referenced by cutting_plane(), and tangentstiff().

void dfdsigma	(	long *	stat,
		long	mu,
		matrix &	dfds
	)

derivatives of yield function with respect of principal stresses for standard stress ordering and ordering given by mu parameter

The function computes derivatives of TRUE ACTIVE yield functions with respect of the principal stresses vector

Parameters:

	mu	- possibly active yield surfaces indicator
	stat	- 2 component array with indicator of active yield surface Two surfaces should be active(stat[i]=1), but one can become inactive for some limit cases during stress return. Array is set in the function mc_msurf_cp depending on the results of yieldfunction(vector&, long, vector&) call.
	dfds	- vector for resulting derivatives (output)

Returns:: The function returns vector of required derivatives.

Created by Tomas Koudelka, 10.11.2003

Definition at line 909 of file mohrc.cpp.

References phi.

Referenced by mc_msurf_cp().

void dgdsigma	(	long *	stat,
		long	mu,
		matrix &	dgds
	)

derivatives of plastic potential function with respect of principal stresses for standard stress ordering and ordering given by mu parameter

The function computes derivatives of TRUE ACTIVE plastic potential functions with respect of the principal stresses vector

Parameters:

	mu	- possibly active yield surfaces indicator
	stat	- 2 component array with indicator of active yield surface Two surfaces should be active(stat[i]=1), but one can become inactive for some limit cases during stress return. Array is set in the function mc_msurf_cp depending on the results of yieldfunction(vector&, long, vector&) call.
	dgds	- vector for resulting derivatives (output)

Returns:: The function returns vector of required derivatives.

Created by Tomas Koudelka, 10.11.2003

Definition at line 963 of file mohrc.cpp.

References psi.

Referenced by mc_msurf_cp().

double give_consparam	(	long	ipp,
		long	ido
	)

returns consistency parameter

The function returns actual value of consistency parameter gamma.

Parameters:

	ipp	- integration point number in the mechmat ip array.
	ido	- index of the first internal variable for given material in the ipp other array

Returns:: The function returns consistency parameter.

Created by Tomas Koudelka,

Definition at line 1053 of file mohrc.cpp.

References intpoints::eqother, mechmat::ip, Mm, and intpoints::ncompstr.

Referenced by mechmat::give_consparam().

void giveirrstrains	(	long	ipp,
		long	ido,
		vector &	epsp
	)

returns plastic strains

Function returns irreversible plastic strains.

Parameters:

	ipp	- integration point number in the mechmat ip array.
	ido	- index of the first internal variable for given material in the ipp other array
	epsp	- vector of irreversible strains

Returns:: The function returns vector of irreversible strains in the parameter epsp.

Created by Tomas Koudelka,

Definition at line 1034 of file mohrc.cpp.

References intpoints::eqother, mechmat::ip, Mm, and vector::n.

Referenced by mechmat::giveirrstrains().

void matstiff	(	matrix &	d,
		long	ipp,
		long	ido
	)

stiffness matrix for given intgration point

The function returns material stiffness matrix for given integration point. Result is stored in the parameter d.

Parameters:

	d	- material stiffness matrix (output)
	ipp	- integration point pointer
	ido	- index of internal variables for given material in the ipp other array

Returns:: The function returns stiffness matrix of the material in the parameter d.

Created by Tomas Koudelka, 10.11.2003

Definition at line 141 of file mohrc.cpp.

References mechmat::elmatstiff(), initial_stiff, matrix::m, Mm, Mp, matrix::n, probdesc::nlman, print_err(), nonlinman::stmat, tangent_stiff, and tangentstiff().

Referenced by mechmat::matstiff().

void mc_msurf_cp	(	long	ipp,
		double &	gamma,
		vector &	epsn,
		vector &	epsp,
		vector &	q,
		long	mu,
		long	ni,
		double	err
	)

multisurface cutting plane algorithm at principal stresses

Function returns stresses on sufrace of plasticity multisurface cutting plane method at principal stresses is used. Parameters gamma,epsp and q will be replaced by new values.

Parameters:

	ipp	- integration point pointer
	gamma	- consistency parameter (input/output)
	epsn	- total strain components
	epsp	- plastic strain components (input/output)
	q	- hardening parameters (input/output)
	mu	- possibly active yield surfaces indicator
	ni	- maximum number of iterations
	err	- required error

Returns:: The function returns actual values of consistency parameter, plastic strains and hardening parameters in the parameters gamma, epsp and q.

Created by Tomas Koudelka, 4.8.2001

Definition at line 629 of file mohrc.cpp.

References vector::a, matrix::a, addm(), addv(), allocm(), allocv(), checkzeropsig(), copyv(), destrm(), destrv(), dfdsigma(), dgdsigma(), elisomat, mechmat::elmatstiff(), f, fillcol(), fillrow(), intpoints::gemid(), gemp(), mechmat::give_actual_nu(), mechmat::give_actual_ym(), glmatrixtransf(), mechmat::ip, lgmatrixtransf(), limit, Mm, Mp, mtxv(), mxm(), mxmt(), mxv(), vector::n, nijac, pelmatstiff(), planestrain, planestress, plasmodscalar(), princ_val(), print_err(), intpoints::ssst, stat, mechmat::storestress(), strain, stress, subv(), tensor_vector(), intpoints::tm, updateq(), vector_tensor(), yieldfunction(), and probdesc::zero.

Referenced by nlstresses(), and nonloc_nlstresses().

void nlstresses	(	long	ipp,
		long	ido
	)

computes stresses at the given integration point

The function computes correct stresses in the integration point and stores them into ip stress array.

Parameters:

	ipp	- integration point pointer
	im	- index of material type for given ip
	ido	- index of internal variables for given material in the ipp other array

Returns:: The function does not return anything.

Created by Tomas Koudelka, 10.11.2001

Definition at line 280 of file mohrc.cpp.

References cp, cutting_plane(), intpoints::eqother, strretalg::give_err(), strretalg::give_ni(), strretalg::give_tsra(), mechmat::ip, mc_msurf_cp(), Mm, intpoints::ncompstr, intpoints::other, print_err(), sra, and intpoints::strain.

Referenced by mechmat::compnonloc_nlstresses(), and mechmat::computenlstresses().

void nonloc_nlstresses	(	long	ipp,
		long	ido
	)

computes stresses at the given integration point from the nonlocal strain values

This function computes stresses at given integration point ipp, depending on the reached averaged nonlocal strains. The cutting plane algorithm is used. The stress and the other attribute of given integration point is actualized.

Parameters:

	ipp	- integration point number in the mechmat ip array.
	ido	- index of internal variables for given material in the ipp other array

Returns:: The function does not return anything.

Created by Tomas Koudelka, 10.11.2001

Definition at line 340 of file mohrc.cpp.

References cp, cutting_plane(), intpoints::eqother, strretalg::give_err(), strretalg::give_ni(), strretalg::give_tsra(), mechmat::ip, mc_msurf_cp(), Mm, intpoints::ncompstr, intpoints::nonloc, intpoints::other, print_err(), sra, and intpoints::strain.

Referenced by mechmat::compnonloc_nlstresses().

void pelmatstiff	(	long	ipp,
		matrix &	d,
		double	e,
		double	nu
	)

elastic stiffness matrix for elastic isotropic material computed at principal stress directions

The function returns material stiffness matrix for given integration point for the principal directions. Result is stored in the parameter d.

Parameters:

	ipp	- integration point pointer
	d	- material stiffness matrix (output)
	e	- Young modulus
	nu	- Poissons ratio

Returns:: The function returns stiffness matrix in the parameter d.

Created by Tomas Koudelka, 10.11.2003

Definition at line 241 of file mohrc.cpp.

References cmulm(), mechmat::ip, Mm, planestrain, planestress, print_err(), spacestress, and intpoints::ssst.

Referenced by cutting_plane(), and mc_msurf_cp().

void plasmodscalar	(	long	ipp,
		vector &	q,
		long	mu,
		matrix &	hcpm
	)

returns hardening contribution for multisurface cutting plane method

The function assembles matrix of plastic moduli used in the multisurface cutting-plane algorithm.

Parameters:

	ipp	- integration point pointer
	q	- hardening parameters
	mu	- possibly active yield surfaces indicator
	hcpm	- matrix of plastic moduli (output)

Returns:: The function returns resulting matrix in the parameter hcpm.

Created by Tomas Koudelka,

Definition at line 778 of file mohrc.cpp.

References fillm().

double plasmodscalar	(	long	ipp,
		vector &	q
	)

returns hardening contribution for cutting_plane method

Function returns plastic modulus in case that hardening/softening rule is adopted

Parameters:

	ipp	- integration point pointer
	q	- hardening parameters

Returns:: Function returns value of plastic modulus.

Created by Tomas Koudelka, 4.11.2003

Definition at line 525 of file mohrc.cpp.

Referenced by cutting_plane(), and mc_msurf_cp().

void read ( XFILE * in )

The function reads material parameters from the opened text file given by the parameter in.

Parameters:

in

- pointer to the opened input text file

Returns:: The function does not return anything.

Created by Tomas Koudelka,

Definition at line 55 of file mohrc.cpp.

References c, phi, psi, strretalg::read(), sra, and xfscanf().

Referenced by mechmat::readmattype().

void tangentstiff	(	matrix &	d,
		matrix &	td,
		long	ipp,
		long	ido
	)

tangent stiffness matrix for given integration point

The function returns tangent material stiffness matrix for given integration point. Result is stored in the parameter d.

Parameters:

	d	- elastic material stiffness matrix
	td	- tangent material stiffness matrix
	ipp	- integration point pointer
	ido	- index of internal variables for given material in the ipp other array

Returns:: The function returns tangent stiffness matrix of the material in the parameter d.

Created by Tomas Koudelka, 10.11.2003

Definition at line 175 of file mohrc.cpp.

References allocv(), cmulm(), copym(), deryieldfsigma(), destrv(), intpoints::eqother, mechmat::givestress(), mechmat::ip, limit, matrix::m, Mm, Mp, mtxv(), mxm(), mxv(), matrix::n, intpoints::ncompstr, nijac, planestrain, planestress, princ_val(), scprd(), intpoints::ssst, stress, subm(), vector_tensor(), vxv(), and probdesc::zero.

Referenced by matstiff().

void updateq	(	long	ipp,
		vector &	epsp,
		vector &	q
	)

updates hardening parameters

Function updates hardening/softening parameter in case that hardening/softening rule is adopted

Parameters:

	ipp	- integration point pointer
	epsp	- plastic strain components
	q	- hardening parameters (output)

Returns:: The function returns udated hardening parameters in the parameter q.

Created by Tomas Koudelka, 4.11.2003

Definition at line 543 of file mohrc.cpp.

Referenced by cutting_plane(), and mc_msurf_cp().

void updateval	(	long	ipp,
		long	im,
		long	ido
	)

updates values of the integration point eqother array with the new reached

The function updates values in the other array reached in the previous equlibrium state to values reached in the new actual equilibrium state.

Parameters:

	ipp	- integration point number in the mechmat ip array.
	im	- index of material type for given ip
	ido	- index of internal variables for given material in the ipp other array

Returns:: The function does not return anything.

Created by Tomas Koudelka,

Definition at line 1013 of file mohrc.cpp.

References intpoints::eqother, mechmat::givencompeqother(), mechmat::ip, Mm, and intpoints::other.

Referenced by mechmat::updateipvalmat().

void yieldfunction	(	vector &	psig,
		long	mu,
		vector &	f
	)

yield function from principal stresses for standard stress ordering and ordering given by mu parameter

The function computes actual values of POSSIBLY ACTIVE yield functions for the multisurface cutting-plane algorithm.

Parameters:

	psig	- vector of principal stresses
	mu	- possibly active yield surfaces indicator
	stat	- 2 component array with indicator of active yield surface Two surfaces should be active(stat[i]=1), but one can become inactive for some limit cases during stress return. Array is set in the function mc_msurf_cp depending on the results of yieldfunction(vector&, long, vector&) call.
	f	- vector of actual values of active yield functions (output)

Returns:: The function returns actual values of active yield function in the parameter f.

Created by Tomas Koudelka, 4.8.2001

Definition at line 861 of file mohrc.cpp.

References c, and phi.

void yieldfunction	(	vector &	psig,
		long	mu,
		long *	stat,
		vector &	f
	)

yield function from principal stresses for standard stress ordering and ordering given by mu and stat parameter

The function computes actual values of TRUE ACTIVE yield functions for the multisurface cutting-plane algorithm.

Parameters:

	psig	- vector of principal stresses
	mu	- possibly active yield surfaces indicator
	stat	- 2 component array with indicator of active yield surface Two surfaces should be active(stat[i]=1), but one can become inactive for some limit cases during stress return. Array is set in the function mc_msurf_cp depending on the results of yieldfunction(vector&, long, vector&) call.
	f	- vector of actual values of active yield functions (output)