mohrco.c

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/*
%M This modules contains the MOHR COULOMB CUTOFF material sub-class methods 
   and definitions
%a Joao Luiz Elias Campos.
%d September 13rd, 1999.
%r $Id: mohrco.c,v 1.1 2004/06/22 05:29:59 joaoluiz Exp $
%w (C) COPYRIGHT 1995-1996, Eduardo Nobre Lages.
   (C) COPYRIGHT 1997-1999, Joao Luiz Elias Campos.
   All Rights Reserved
   Duplication of this program or any part thereof without the express
   written consent of the author is prohibited.

   Modificacao: 28/04/2005    Alexandre A. Del Savio
     Foram substituídas todas as alocações dinâmicas feitas com malloc 
     por calloc.

*/

/*
** ------------------------------------------------------------------------
** Global variables and symbols:
*/
#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include "load.h"
#include "elm.h"
#include "material.h"
#include "node.h"
#include "rio.h"


/* Parent methods
 */
void MaterialTimeStep( sMaterial *, double * );
void MaterialDensity ( sMaterial *, double * );


/*
** ------------------------------------------------------------------------
** Local variables and symbols:
*/

/*
%T MOHR COULOMB CUTOFF material data definition
*/
typedef struct _mohrcodata
{
 double E;             /* Young modulos          */
 double Nu;            /* Poisson coefficient    */
 double C;             /* Coesion value          */
 double Phi;           /* Friction angle         */
 double Psi;           /* Expansion angle        */
 double St;            /* Traction stress cutoff */
} sMohrCOData;

#ifndef PI
#define PI 3.141592654
#endif

/*
** ------------------------------------------------------------------------
** Local functions:
*/


/*
** ------------------------------------------------------------------------
** Subclass methods:
*/
static void MohrCoulombCutOffNew         ( int, sMaterial ** );
static void MohrCoulombCutOffFree        ( sMaterial * );
static void MohrCoulombCutOffRead        ( sMaterial * );
static void MohrCoulombCutOffEParameter  ( sMaterial *, double * );
static void MohrCoulombCutOffNuParameter ( sMaterial *, double * );
static void MohrCoulombCutOffCMatrix     ( sMaterial *, double [6][6] );
static void MohrCoulombCutOffUpdateStress( sMaterial *, double, double *,
                                                        double *, double *,
                                                        double * );


/*
%F This method allocates memory for a MOHR COULOMB CUTOFF material and fills 
   its data with the specific values.
%i Material label (number)
%o Material descriptor.
*/
static void MohrCoulombCutOffNew( int label, sMaterial **mat )
{
 sMohrCOData *data = 0L;

/* Get memory for the material descriptor
 */
 (*mat) = (sMaterial *)calloc(1, sizeof(sMaterial) );

/* Get memory for the MOHR COULOMB CUTOFF material data
 */
 data = (sMohrCOData *)calloc(1, sizeof(sMohrCOData) );

/* Fill MOHR COULOMB CUTOFF material data
 */
 data->E   = 0.0;
 data->Nu  = 0.0;
 data->C   = 0.0;
 data->Phi = 0.0;
 data->Psi = 0.0;
 data->St  = 0.0;

/* Fill material descriptor
 */
 (*mat)->type  = MOHR_COULOMB_CUTOFF;
 (*mat)->label = label;
 (*mat)->Gamma = 0.0;
 (*mat)->data  = (void *)data;

/* Add to the material list
 */
 MatList[label-1] = (*mat);

} /* End of MohrCoulombCutOffNew */


/*
%F This method frees the MOHR COULOMB CUTOFF material data for a given 
   material.
%i Material descriptor.
*/
static void MohrCoulombCutOffFree( sMaterial *mat )
{
 sMohrCOData *data = 0L;

/* Get MOHR COULOMB CUTOFF material data
 */
 data = (sMohrCOData *)mat->data;

/* Release allocated memory
 */
 free( data );

/* Reset material data
 */
 mat->data = 0L;

} /* End of MohrCoulombCutOffFree */


/*
%F This method reads the MOHR COULOMB CUTOFF material information.
%i Material descriptor.
*/
static void MohrCoulombCutOffRead( sMaterial *mat )
{
 sMohrCOData *data = 0L;
 double       c, nu, e, phi, psi, st;

/* Get the material data
 */
 data = (sMohrCOData *)mat->data;

/* Read the material parameters
 */
 fscanf( nf, "%lf %lf %lf %lf %lf %lf", &e, &nu, &c, &phi, &psi, &st );

/* Fill material information
 */
 data->E   = e;
 data->Nu  = nu;
 data->C   = c;
 data->Phi = phi;
 data->Psi = psi;
 data->St  = st;

} /* End of MohrCoulombCutOffRead */

/*
%F
*/
static void MohrCoulombCutOffEParameter( sMaterial *mat, double *e )
{
 sMohrCOData *data = 0L;

/* Get material descriptor
 */
 data = (sMohrCOData *)mat->data;

/* Get Young modules parameters
 */
 (*e) = data->E;

} /* End of MohrCoulombCutOffEParameter */


/*
%F 
*/ 
static void MohrCoulombCutOffNuParameter( sMaterial *mat, double *nu )
{
 sMohrCOData *data = 0L;

/* Get material descriptor
 */
 data = (sMohrCOData *)mat->data;

/* Get Poisson coefficient parameters
 */
 (*nu) = data->Nu;

} /* End of MohrCoulombCutOffNuParameter */


/*
%F This function computes the material constitutive matrix
*/
static void MohrCoulombCutOffCMatrix( sMaterial *mat, double cm[6][6] )
{
 int          i, j;
 sMohrCOData *data = 0L;
 double       e, nu;

/* Intialize matrix
 */
 for( i = 0; i < 6; i++ )
  for( j = 0; j < 6; j++ )
   cm[i][j] = 0.0;

/* Get material descriptor
 */ 
 data = (sMohrCOData *)mat->data;

/* Get element parameters
 */
 e  = data->E;
 nu = data->Nu;

/* Compute matrix elements
 */
 if( NDof == 3 )
 {
  cm[0][0] =
  cm[1][1] =
  cm[2][2] =  e*(nu*nu-1.0) / (nu*(nu+nu*nu)+nu*(nu*nu+nu)+nu*nu-1.0);
  cm[1][0] =
  cm[2][0] =
  cm[0][1] =
  cm[2][1] =
  cm[0][2] =
  cm[1][2] = -e*(nu*nu+nu) / (nu*(nu+nu*nu)+nu*(nu*nu+nu)+nu*nu-1.0);
  cm[3][3] =
  cm[4][4] =
  cm[5][5] = (e * e) / (e + e * (1.0 + 2.0 * nu));
 }
 else
 {
  cm[0][0] = cm[1][1] = (e * (1.0 - nu)) / ((1.0 + nu) * (1.0 - (2.0 * nu)));
  cm[0][1] = cm[1][0] = (e * nu) / ((1.0 + nu) * (1.0 - (2.0 * nu)));
  cm[2][2] = e / (2.0 * (1.0 + nu));
 }

} /* End of MohrCoulombCutOffCMatrix */


/*
%F
*/
static void MohrCoulombCutOffUpdateStress( sMaterial *mat, double dtime, 
                                           double *yield, double *effdef, 
                                           double *str, double *def )
{
 sMohrCOData *data = 0L;
 double       sig1, sig3, sig2;
 double       c, phi, psi, st, pf1, pf2, mult, aldp, ni;
 double       cm[6][6];

/* Get material data
 */
 data = (sMohrCOData *)mat->data;

/* Get material contitutive matrix
 */
 MohrCoulombCutOffCMatrix( mat, cm );
 
/* Get material poisson coef.
 */
 MohrCoulombCutOffNuParameter( mat, &ni );

/* Get material plastic properties
 */ 
 c   = data->C;
 phi = data->Phi;
 psi = data->Psi;
 st  = data->St;

/* Computes the principal stresses (Sigma 1 and Sigma 3)
 */
 sig1 = ((str[0] + str[1]) / 2.0) -
        sqrt( (str[0] - str[1])*(str[0] - str[1])/4.0 + str[2] * str[2] );
 sig3 = ((str[0] + str[1]) / 2.0) +
        sqrt( (str[0] - str[1])*(str[0] - str[1])/4.0 + str[2] * str[2] );
 sig2 = ni * (sig1 + sig3);

/* Computes the angle
 */
 phi *= PI / 180.0;
 phi  = (1.0 + sin(phi)) / (1.0 - sin(phi));

/* Compute plastic functions
 */
 pf1      = sig1 - (sig3 * phi) + (2.0 * c * sqrt(phi));
 if( sig3 > 0.0 )
  pf2 = st - sig3;
 else
  pf2 = 1.0;
 (*yield) = 1.0;

/* Correct the stress if necessery
 */
 if( pf2 <= 0.0 )
 {
  (*yield) = pf2;

  if( sig1 == str[0]) aldp = 0.0;
  else                aldp = atan2( (sig1 - str[0]), str[2] );

  mult = pf2 / cm[0][0];

  sig1 -= mult * cm[0][1];
  sig2 -= mult * cm[0][1];
  sig3 -= mult * cm[0][0];

  str[0] = ((sig1 + sig3) / 2.0) + ((sig1-sig3) * cos(2.0 * aldp) / 2.0);
  str[1] = ((sig1 + sig3) / 2.0) - ((sig1-sig3) * cos(2.0 * aldp) / 2.0);
  str[2] = ((sig1 - sig3) * (sin(2.0 * aldp))) / 2.0;
  str[3] = sig2;
 }
 else if( pf1 <= 0.0 )
 {
  (*yield) = pf1;

  if( sig1 == str[0]) aldp = 0.0;
  else                aldp = atan2( (sig1 - str[0]), str[2] );

  mult = pf1 / (-cm[0][0] * (1.0 + (phi*psi)) + (2.0 * phi * cm[0][1]));

  sig1 += mult * (cm[0][0] - (cm[0][1] * psi));
  sig3 += mult * (cm[0][1] - (cm[0][0] * psi));
  sig2 += mult * cm[0][0] * (1.0 - psi);

  str[0] = ((sig1 + sig3) / 2.0) + ((sig1-sig3) * cos(2.0 * aldp) / 2.0);
  str[1] = ((sig1 + sig3) / 2.0) - ((sig1-sig3) * cos(2.0 * aldp) / 2.0);
  str[2] = ((sig1 - sig3) * (sin(2.0 * aldp))) / 2.0;
  str[3] = sig2;
 }

} /* End of MohrCoulombCutOffUpdateStress */


/*
** ------------------------------------------------------------------------
** Public functions:
*/

/*
%F This function initializes the sub-class "MOHR COULOMB CUTOFF".
*/
void MohrCoulombCutOffInit( void );
void MohrCoulombCutOffInit( void )
{
/* Initialize MOHR COULOMB CUTOFF material sub-class
 */
 MatClass[MOHR_COULOMB_CUTOFF].new       = MohrCoulombCutOffNew;
 MatClass[MOHR_COULOMB_CUTOFF].free      = MohrCoulombCutOffFree;
 MatClass[MOHR_COULOMB_CUTOFF].read      = MohrCoulombCutOffRead;
 MatClass[MOHR_COULOMB_CUTOFF].epar      = MohrCoulombCutOffEParameter;
 MatClass[MOHR_COULOMB_CUTOFF].nupar     = MohrCoulombCutOffNuParameter;
 MatClass[MOHR_COULOMB_CUTOFF].cmatrix   = MohrCoulombCutOffCMatrix;
 MatClass[MOHR_COULOMB_CUTOFF].updatestr = MohrCoulombCutOffUpdateStress;
 MatClass[MOHR_COULOMB_CUTOFF].updatepar = 0L;
 MatClass[MOHR_COULOMB_CUTOFF].timestep  = MaterialTimeStep;
 MatClass[MOHR_COULOMB_CUTOFF].density   = MaterialDensity;
 MatClass[MOHR_COULOMB_CUTOFF].vstrain   = 0L;

} /* End of MohrCoulombCutOffInit */


/* =======================================================  End of File  */

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