camclay.h

Finite element program for mechanical problem. It can solve various problem in solid problem

#ifndef CAMCLAY_H
#define CAMCLAY_H

#include "iotools.h"
#include "alias.h"
#include "strretalg.h"
struct matrix;
struct vector;
struct atsel;

/**
   This class defines modified cam-clay material model
   the material is defined by three material constants :
   m - is frictional constant and it depends on the frictional angle phi
   lambda - slope of the normal consolidationa line
   kappa  - slope of the swelling line
   
   In addition to these material constants several initial values 
   have to be specified at each integration point in the following order :
   v1   - initial specific volume at the reference pressure p1 after unloading from 
          initial consolidation pressure p_c0 (v_kappa0)
   p1   - reference pressure (p_1), it has to be negative value
   p_c0 - initial consolidation pressure, it has to be negative value
   inisig_1 - inisig_ncompstr - components of initial stresses
   
   Order of the eqother array components
   id                | description
   ------------------+------------------------------------------------
   <0;  ncompstr-1>  | plastic strains 
    ncompstr         | gamma - consistency parameter 
    ncompstr+1       | hardening parameter p_c - consolidation pressure
    ncompstr+2       | v_pc0 - initial value of consolidation pressure
        .            | v_lambda1 - initial value of specific volume on the NCL at reference pressure p1
        .            | v_ini - initial specific volume
        .            | i1s - mean stress 
        .            | j2s - the second invariant of stress deviator
        .            | epsv - total volume strain 
    ncompstr+8       | epsvp - plastic volume strain  
   

   18.1.2005
   TKo
*/

class camclay
{
 public:
  camclay (void);
  ~camclay (void);
  void read (XFILE *in);
  double cohesion(vector &qtr);
  double yieldfunction (matrix &sig, vector &q);
  void deryieldfsigma (matrix &sig, vector &q, matrix &dfds);
  void dderyieldfsigma (matrix &ddfds);
  void derpotsigma (matrix &sig, vector &q, matrix &dgds);
  void deryieldfq(matrix &sig, vector &dq);
  void deryieldfdqdq(matrix &dfq);
  void deryieldfdsdq(matrix &dfdsdqt);
  void dqdsigma(matrix &sigt, vector &qt, matrix &dqds);
  void dhardfdq(long ipp, long ido, double dgamma, vector &qt, matrix &dqdq);
  void der_q_gamma(long ipp, long ido, matrix &sig, vector &qtr, vector &dqdg);
  double plasmodscalar(long ipp, long ido, matrix &sig, vector &qtr);
  void updateq(long ipp, long ido, vector &eps, vector &epsp, matrix &sig, vector &q);
//  void updateq(vector &epsp, strastrestate ssst, vector &q);
  void matstiff (matrix &d, long ipp,long ido);
  void nlstresses (long ipp,long im,long ido);
  void updateval (long ipp,long ido);
  void giveirrstrains (long ipp, long ido, vector &epsp);
  double give_consparam (long ipp, long ido);
  void changeparam (atsel &atm,vector &val);


  /// frictional constant
  double m;

  /// slope of normal consolidation line
  double lambda;

  /// slope of swelling line
  double kappa;

  ///  stress return algorithm
  strretalg sra;
};

#endif