BoucWen1dMat

Purpose

Bouc-Wen-Baber hysteretic-degrading material

Synopsis

MatResp = BoucWen1dMat (action,Mat_no,MatData,MatState)

Description

BOUCWEN1dMAT Bouc-Wen-Baber hysteretic-degrading material    
  MATRESP = BOUCWEN1dMAT (ACTION,MATNO,MATDATA,MATSTATE)
  function for Bouc-Wen-Baber hysteretic-degrading material
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  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 = 'init'
  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 MatState 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 tangent modulus; returned under ACTION = 'stif'
         sig    = stress (tensor for 2d or 3d); returned under ACTION = 'stif' or 'forc'
         Past   = material history variables at last converged MatState
         Pres   = current values of material history variables
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  MATDATA is a data structure with material property information in fields
         alp(ha) = hardening ratio
         bet(a)  = controls hysteretic capacity
         gam(ma) = controls pinching
        .del(ta) = controls difference in positive and negative strength
        .E       = initial modulus
        .m       = exponent of transition from elastic to plastic
        .eta0    = initial yield strain
        .lam_eta = controls stiffness degradation
        .A0      = default to 1
        .lam_A   = controls both stiffness and strength degradation
        .nu0     = default to 1
        .lam_nu  = controls strength degradation

 Material History Variables
 q   : hysteretic variable
 w   : hysteretic work (parameter's degradation are proportional to this work)
 sig : stress (only for postprocessing purposes)
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  MATPOST is a data structure with material response information for MatPost-processing in fields
         eps = total strain
         sig = uniaxial stress

Cross-Reference Information

This function calls: