FrictionGap1dMat

Purpose

friction gap 1d model defined as a piecewise function with

Synopsis

MatResp = FrictionGap1dMat (action,MatNo,MatData,MatState)

Description

  FRICTIONGAP1dMAT friction gap 1d model defined as a piecewise function with
  any constituent material response inside friction limits and linear elastic response outside
  MATRESP = FRICTIONGAP1dMAT (ACTION,MAT_NO,MATDATA,MatState)
  the function determines the current material state under total strain EPSI 
  for a linear elastic model when epsi is outside friction strain limits, 
  and the response for the constituent basic material inside those limits. 
  History variables of the constituent basic material are stored in MatState.Pres.CMat. 
  Friction limit in terms of total strain is defined, fricx.
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  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 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):
             Pgap  = maximum friction limit
             Ngap  = minimum friction limit
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  MATDATA is a data structure with material property information; it has the fields
         E    = initial elastic modulus
         fy   = friction stress
         Mgap = gap magnification factor
         Pgap = initial positive gap
         Ngap = initial negative gap
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  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:

• InelLPwLH1dMat inelastic linear-plastic 1d model with linear kinematic and isotropic hardening