hissplas Class Reference

#include <hissplas.h>

Public Member Functions
void	changeparam (atsel &atm, vector &val)
	function changes material parameters (used in stochastic calculations)
void	derplaspotsigma (long ipp, vector &dgds)
	derivatives of plastic potential function with respect of stresses
void	deryieldfsigma (long ipp, vector &dfds)
	derivatives of yield function with respect of stresses
double	dfdepspd (long ipp, double i1, double j2, matrix &dev, double ksi, matrix &depsp)
	derivatives of yield function with respect to the increment of plastic deviatoric strain
double	dfdepsvp (long ipp, double i1, double alpha, double gamma, double ksi, matrix &depsp)
	derivatives of yield function with respect to the increment of plastic volumetric strain
double	dg1depsdp (long ipp, double i1, double j2, double alpha, double gamma, matrix &dev, double depsvp, double depsdp, double ksi, matrix &depsp)
	derivatives of g1 = (df/d[sqrt(j2)])deps_vp - df/dI1deps_dp with respect to increment of plastic deviatoric strain
double	dg1depsvp (long ipp, double i1, double j2, double alpha, double gamma, matrix &dev, double depspd, double ksi, matrix &depsp)
	derivatives of g1 = (df/d[sqrt(j2)])deps_vp - df/dI1deps_dp with respect to increment of plastic volumetric strain
double	g1function (double depsvp, double depsdp, double i1, double j2, double alpha, double gamma)
	condition of modified flow rule (g1 function)
double	give_consparam (long ipp, long ido)
	returns consistency parameter
void	giveirrstrains (long ipp, long ido, vector &epsp)
	returns plastic strains
	hissplas (void)
void	matstiff (matrix &d, long ipp, long ido)
	stiffness matrix for given intgration point
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	read (XFILE *in)
void	updateq (long ipp, matrix &depspt, matrix &sigt, matrix &depst, vector &q)
	updates hardening parameters
void	updateval (long ipp, long ido)
	updates values of the integration point eqother array with the new reached
double	yieldfunction (matrix sigt, vector &q)
	yield function (computed from stress tensor)
double	yieldfunction (double i1, double j2, double cos3t, vector &q)
	yield function (computed from stress invariants)
	~hissplas (void)
Public Attributes
double	alpha1
	coefficient influencing limit value of hardening parameter alpha
double	beta
	shape parameter (beta=0 circular corss-section, beta > 0.0 cross-section -> triangular)
double	eta1
	parameter controlling hardening
double	gamma_max
	maximum value of isotropic measure of response surface degradation (gamma)
double	k
	softening (degradation) parameter
double	ksi_lim
	limit value of norm of plastic strains used in hardening
double	n
double	pa
	atmospheric pressure
double	r
	triaxial tensile strength
strretalg	sra
	stress return algorithm

Detailed Description

Definition at line 11 of file hissplas.h.

Constructor & Destructor Documentation

hissplas ( void )

Default constructor - sets material parameters to the initial (zero) values

Created by TKo 01.2010

Definition at line 20 of file hissplas.cpp.

References alpha1, beta, eta1, gamma_max, k, ksi_lim, n, pa, and r.

~hissplas ( void )

Default destructor

Created by TKo 01.2010

Definition at line 32 of file hissplas.cpp.

Member Function Documentation

void changeparam	(	atsel &	atm,
		vector &	val
	)

function changes material parameters (used in stochastic calculations)

void derplaspotsigma	(	long	ipp,
		vector &	dgds
	)

derivatives of plastic potential function with respect of stresses

void deryieldfsigma	(	long	ipp,
		vector &	dfds
	)

derivatives of yield function with respect of stresses

double dfdepspd	(	long	ipp,
		double	i1,
		double	j2,
		matrix &	dev,
		double	ksi,
		matrix &	depsp
	)

derivatives of yield function with respect to the increment of plastic deviatoric strain

The function returns derivatives of the yield function with respect to the plastic deviatoric strain for the given stress state.

Parameters:

	ipp	- integration point pointer
	i1	- first invariant of trial stress tensor
	j2	- second invariant of trial stress tensor
	dev	- deviator of trial stress second order tensor
	ksi	- norm of plastic strain tensor
	depsp	- tensor of plastic strain increments for the actual step

Return values:

The

function returns a derivative of yield function with respect to plastic deviatoric strain.

Created by TKo 01.2010

Definition at line 225 of file hissplas.cpp.

References alpha1, eta1, g, mechmat::give_actual_nu(), mechmat::give_actual_ym(), ksi_lim, Mm, n, pa, r, tensor2_inner_prod(), and tensornorm().

Referenced by nlstresses().

double dfdepsvp	(	long	ipp,
		double	i1,
		double	alpha,
		double	gamma,
		double	ksi,
		matrix &	depsp
	)

derivatives of yield function with respect to the increment of plastic volumetric strain

The function computes a derivative of the yield function with respect to the plastic volumetric strain for the given stress state.

Parameters:

	ipp	- integration point pointer
	i1	- first invariant of stress tensor
	alpha	- hardening parameter
	gamma	- softening parameter
	ksi	- norm of plastic strain tensor
	depsp	- tensor of plastic strain increments for the actual step

Return values:

The

function returns a derivative of yield function with respect to plastic volumetric strain.

Created by TKo 01.2010

Definition at line 174 of file hissplas.cpp.

References alpha1, eta1, first_invar(), mechmat::give_actual_nu(), mechmat::give_actual_ym(), k, ksi_lim, Mm, n, pa, r, and tensornorm().

Referenced by nlstresses().

double dg1depsdp	(	long	ipp,
		double	i1,
		double	j2,
		double	alpha,
		double	gamma,
		matrix &	dev,
		double	depsvp,
		double	depsdp,
		double	ksi,
		matrix &	depsp
	)

derivatives of g1 = (df/d[sqrt(j2)])*deps_vp - df/dI1*deps_dp with respect to increment of plastic deviatoric strain

The function returns derivatives of g1 = (df/d[sqrt(j2)])*deps_vp - df/dI1*deps_dp with respect to increment of plastic deviatoric strain.

Parameters:

	ipp	- integration point pointer
	i1	- first invariant of trial stress tensor
	j2	- second invariant of trial stress tensor
	alpha	- hardening parameter
	gamma	- softening parameter
	dev	- deviator of trial stress second order tensor
	depsvp	- increment of volumetric plastic strains
	depsdp	- increment of deviatoric
	ksi	- norm of plastic strain tensor
	depsp	- tensor of plastic strain increments for the actual step

Return values:

The

function returns a derivative of yield function with respect to plastic deviatoric strain.

Created by TKo 01.2010

Definition at line 356 of file hissplas.cpp.

References alpha1, eta1, g, mechmat::give_actual_nu(), mechmat::give_actual_ym(), ksi_lim, Mm, n, pa, r, tensor2_inner_prod(), and tensornorm().

Referenced by nlstresses().

double dg1depsvp	(	long	ipp,
		double	i1,
		double	j2,
		double	alpha,
		double	gamma,
		matrix &	dev,
		double	depsdp,
		double	ksi,
		matrix &	depsp
	)

derivatives of g1 = (df/d[sqrt(j2)])*deps_vp - df/dI1*deps_dp with respect to increment of plastic volumetric strain

The function returns derivatives of g1 = (df/d[sqrt(j2)])*deps_vp - df/dI1*deps_dp with respect to increment of plastic volumetric strain.

Parameters:

	ipp	- integration point pointer
	i1	- first invariant of trial stress tensor
	j2	- second invariant of trial stress tensor
	alpha	- hardening parameter
	gamma	- softening parameter
	dev	- deviator of trial stress second order tensor
	depsdp	- increment of equivalent deviatoric plastic strain
	ksi	- norm of plastic strain tensor
	depsp	- tensor of plastic strain increments for the actual step

Return values:

The

function returns a derivative of yield function with respect to plastic deviatoric strain.

Created by TKo 01.2010

Definition at line 285 of file hissplas.cpp.

References alpha1, eta1, first_invar(), mechmat::give_actual_nu(), mechmat::give_actual_ym(), k, ksi_lim, Mm, n, pa, r, and tensornorm().

Referenced by nlstresses().

double g1function	(	double	depsvp,
		double	depsdp,
		double	i1,
		double	j2,
		double	alpha,
		double	gamma
	)

condition of modified flow rule (g1 function)

The function returns value of expression g1 = df/d[sqrt(J2)] * depsvp - df/dI1 * depsdp. The above expression represents condition of modified flow rule.

Parameters:

	depsvp	- increment of volumetric plastic strain
	depsdp	- increment of equivalent deviatoric plastic strain
	i1	- first invariant of stress tensor
	j2	- second invariant of trial stress tensor
	alpha	- hardening parameter
	gamma	- softening parameter

Definition at line 145 of file hissplas.cpp.

References n, pa, and r.

Referenced by nlstresses().

double give_consparam	(	long	ipp,
		long	ido
	)

returns consistency parameter

The function returns actual value of the consistency parameter.

Parameters:

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

Return values:

The

function returns actual value of the consistency parameter.

Created by TKo 01.2010

Definition at line 776 of file hissplas.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

The function returns actual value of the irrevesible(plastic) strains.

Parameters:

	ipp	- integration point number in the mechmat ip array.
	ido	- index of internal variables for given material in the ipp other array
	epsp	- vector actual values of plastic strains

Return values:

The

function returns vector of actual values of the irreversible strains in the output parameter epsp.

Created by TKo 01.2010

Definition at line 750 of file hissplas.cpp.

References intpoints::eqother, mechmat::ip, Mm, vector::n, intpoints::ncompstr, and print_err().

Referenced by mechmat::giveirrstrains().

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

stiffness matrix for given intgration point

The function returns material siffness matrix.

Parameters:

	ipp	- integration point pointer
	d	- material stiffness matrix

Return values:

The

function returns resulting stiffness matrix in the output parameter d.

Created by TKo 01.2010

Definition at line 409 of file hissplas.cpp.

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

Referenced by mechmat::matstiff().

void nlstresses	(	long	ipp,
		long	ido
	)

computes stresses at the given integration point

Parameters:

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

Return values:

The

function computes stresses for the actual strains and stores them in the stress array at the given integration point.

Created by TKo 01.2010

Definition at line 454 of file hissplas.cpp.

References addm(), addv(), cmulm(), copym(), copyv(), deviator(), dfdepspd(), dfdepsvp(), dg1depsdp(), dg1depsvp(), mechmat::elip, mechmat::elmatstiff(), intpoints::eqother, strretalg::err, f, first_invar(), g1function(), gause(), h(), mechmat::ip, Mm, mxv(), intpoints::ncompstr, strretalg::ni, normv(), intpoints::other, pa, print_err(), r, second_invar(), sra, intpoints::ssst, mechmat::storestress(), strain, intpoints::strain, stress, subv(), tensor_vector(), third_invar(), updateq(), vector_tensor(), and yieldfunction().

Referenced by mechmat::computenlstresses().

void nonloc_nlstresses	(	long	ipp,
		long	ido
	)

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

The function computes stresses in the given integration point.

Parameters:

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

Return values:

The

function returns stresses computed from the actual strains and nonlocal averaged values.

Created by TKo 01.2010

Definition at line 439 of file hissplas.cpp.

void read ( XFILE * in )

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

Parameters:

in

- pointer to the opened XFILE

Returns:: The function does not return anything.

Created by TKo 02.2010

Definition at line 48 of file hissplas.cpp.

References alpha1, beta, eta1, gamma_max, ksi_lim, n, pa, r, strretalg::read(), sra, and xfscanf().

Referenced by mechmat::readmattype().

void updateq	(	long	ipp,
		matrix &	depspt,
		matrix &	sigt,
		matrix &	depst,
		vector &	q
	)

updates hardening parameters

The function updates hardening parameters according to actual values of plastic strains and other parameters used for the hardening.

Parameters:

	ipp	- integration point number in the mechmat ip array.
	depspt	- tensor of actual plastic strain increments
	sigt	- stress tensor
	depst	- tensor of actual strain increments
	q	- vector of updated values of hardening parameters (input/output)

Return values:

The

function returns updated vector of hardening parameters in the output parameter q.

Created by TKo 01.2010

Definition at line 677 of file hissplas.cpp.

References alpha1, eta1, gamma_max, k, ksi_lim, tensor2_inner_prod(), and tensornorm().

Referenced by nlstresses().

void updateval	(	long	ipp,
		long	ido
	)

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

The function updates internal variables according to actual values of plastic strains and other parameters used for the hardening.

Parameters:

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

Return values:

The

function does not return anything.

Created by TKo 01.2010

Definition at line 721 of file hissplas.cpp.

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

Referenced by mechmat::updateipvalmat().

double yieldfunction	(	matrix	sigt,
		vector &	q
	)

yield function (computed from stress tensor)

The function returns value of the yield function for the given stress state defined by stress tensor. Yield function is defined as f = {J_2}{{p_a}^2} - F_b F_c = 0, where F_b = [ -({I_1+R}{p_a})^n + ({I_1+R}{p_a})^2 ] F_c = (1- 3 )^{-1/2} 3 = {3{3}}{2} {J_3}{{J_2}^{3/2}}

Parameters:

	sigt	- stress tensor
	q	- vector of hardening parameters (i.e. alpha)

Return values:

The

function returns the value of the yield function

Created by TKo 01.2010

Definition at line 113 of file hissplas.cpp.

References deviator(), f, first_invar(), second_invar(), third_invar(), and yieldfunction().

double yieldfunction	(	double	i1,
		double	j2,
		double	cos3t,
		vector &	q
	)

yield function (computed from stress invariants)

The function returns value of the yield function for the given stress state defined by stress invariants. Yield function is defined as f = {J_2}{{p_a}^2} - F_b F_c = 0, where F_b = [ -({I_1+R}{p_a})^n + ({I_1+R}{p_a})^2 ] F_c = (1- 3 )^{-1/2} 3 = {3{3}}{2} {J_3}{{J_2}^{3/2}}

Parameters:

	i1	- first invariant of stress tensor I1
	j2	- second invariant of stress deviator J2
	cos3t	- Lode's angle (cos3t = 3sqrt(3)/2 J3/sqrt(J2^2)
	q	- vector of hardening parameters (i.e. alpha)