Steel021dMat

Purpose

inelastic linear-plastic 1d model with linear isotropic

Synopsis

MatResp = Steel021dMat (action,MatNo,MatData,MatState)

Description

Steel021dMAT inelastic linear-plastic 1d model with linear isotropic
hardening. A translation of the OpenSees model Steel02.
  MATRESP = Steel012dMAT (ACTION,MAT_NO,MATDATA,MATSTATE)
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  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
         Deps   = strain increments from last convergence
         DDeps  = strain increments from last iteration
         epsdot = strain rate
         km     = material stiffness matrix; returned under ACTION = 'stif'
         sig    = stress; returned under ACTION = 'stif' or 'forc'
         Past   = material history variables at last converged state
         Pres   = current values of material history variables
             Past and Pres contain the following history variable(s):
             
             epsmin = Minimum strain in compression
             epsmax = Maximum strain in tension
             epsp1 = plastic excursion
             epss0 = eps at asymptotes intersection
             sigs0 = sig at asymptotes intersection;
             epssr = eps at last inversion point
             sigsr = sig at last inversion point
             kon = index for loading/unloading
             
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  MATDATA is a data structure with material property information; it has the fields
         E0  = initial modulus
         fy = yield strength
         b = strain-hardening ratio ( =Eh/E)
         a1 = isotropic hardening parameter in compression, 
             increase of compression yield envelope as 
             proportion of yield strength after a plastic strain of $a2*($Fy/E0). (optional)
         a2 = isotropic hardening parameter in compression (see explanation under $a1). (optional).
         a3 = isotropic hardening parameter in tension, increase of tension yield envelope as 
             proportion of yield strength after a plastic strain of $a4*($Fy/E0). (optional)
         a4 = isotropic hardening parameter in tension (see explanation under $a3). (optional)
         R0 = exp transition elastic-plastic
         cR1 = coefficient for changing R0 to R
         cR2 = coefficient for changing R0 to R
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  MATPOST is a data structure with material response information for post-processing in fields
         eps   = total strain
         sig    = uniaxial stress

Cross-Reference Information

This function calls: