InelGP1dMat

Purpose

inelastic generalized plasticity 1d material model

Synopsis

MatResp = InelGP1dMat (action,MatNo,MatData,MatState)

Description

INELGP1dMAT inelastic generalized plasticity 1d material model
  MATRESP = INELGP1dMAT (ACTION,MATNO,MATDATA,MATSTATE)
  the function determines the stress-strain relation for a 1d material
               under generalized plasticity with different hardening rules
  Reference: Aurrichio/Taylor,International Journal of Plasticity, vol.11, pp.65-98,1995
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  the character variable ACTION should have one of the following values
  ACTION = 'chec' function checks material property data for omissions and returns default values in MATDATA
           'init' function returns the material history variables in MATSTATE
           'forc' function returns the material stress (tensor) in MATSTATE
           'stif' function returns the material tangent modulus and the stress (tensor) in MATSTATE
           'post' function returns data structure MATPOST with post-processing information
  depending on the value of character variable ACTION the function returns information in data structure MATRESP
  for the material with number MAT_NO; data structure MATDATA supplies the material property data
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  data structure MATRESP stands for one of the following data objects depending on value of ACTION
  MATRESP = MATDATA   for action = 'chec'
  MATRESP = MATSTATE  for action = 'hist'
  MATRESP = MATSTATE  for action = 'stif'
  MATRESP = MATSTATE  for action = 'forc'
  MATRESP = MATPOST   for action = 'post'
  MATRESP is empty    for unsupported keywords
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  MATSTATE is a data structure with information about the current material state in fields
         eps    = total strain (tensor for 2d or 3d)
         Deps   = strain increments from last convergence
         DDeps  = strain increments from last iteration
         epsdot = strain rate (tensor for 2d or 3d)
         km     = material stiffness matrix; returned under ACTION = 'stif'
         sig    = stress (tensor for 2d or 3d); returned under ACTION = 'stif' or 'forc'
         Past   = material history variables at last converged state
         Pres   = current values of material history variables
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  MATDATA is a data structure with material property information; it has the fields
         E  = initial modulus
         fy = yield stress
         nu = Poisson's ratio
         Hi = isotropic hardening modulus
         Hk = kinematic hardening modulus
         delta = speed of material approach to asymptotic behavior
         phi   = distance between asymptotic and current radius of yield function
         Hnl   = nonlinear kinematic hardening parameter
         HRule = hardening rule (Options: 'LP','GP','NLK')
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  MATPOST is a data structure with material response information for post-processing in fields
         eps   = total strain
         sig   = uniaxial stress
         eps_p = plastic strain

Cross-Reference Information

This function calls:

• Hardening library of hardening functions for plasticity models