I am working in Abaqus, aiming to model double porosity clay consolidation data by using hypoplastic clay model with meta stable structure. First, i just wanted to verify basic model using simple axisymmetric geometry (Triaxial Test) in Abaqus. So i used material Parameters as : 22.611e-5,.11,.016,.4 and rest all zero. As a standard procedure i included umat_hcea.for file in the job module and ran my job. I got the error that UMAT was missing, so i opened the umat_hcea.for and replaced first word after usersubroutine by UMAT and finally job completed successfully. I am simply loading under isotropic conditions and then unloading but my when i checked the void ratio upon unloading, it didn’t follow k line it retracted along lambda curve only. Also the void ratio is decreasing not along butterfield’s criteria but along e-lnp’ space (i checked by hand calculations). Can any one suggest me where i could be wrong and also, is there any change that i have to make in the fortran file like the one mentioned above?. Any help would be great .

  1. Lovinder Mann Author
    Lovinder Mann 2 years ago

    My issue has been resolved, i think it was related to initialization of State depenedent Varaiables. Once i did that results are fine.

    • Shruthija Sreeram
      Shruthija Sreeram 4 months ago

      can you please let me know how to initialize state dependent variables?
      Is it through sdvini subroutine? if so can you please forward me the fortran file which includes both sdvini and umat subroutines.

      • Prasanjit Roy
        Prasanjit Roy 4 months ago

        i have added the following code to umat plz check if it works-

        subroutine sdvini(statev,coords,nstatv,ncrds,noel,npt,layer,kspt)
        statev(1) = 0
        statev(2) = 0
        statev(3) = 0
        statev(4) = 0
        statev(5) = 0
        statev(6) = 0
        statev(7) = 0.52
        statev(8) = 0
        statev(9) = 0
        statev(10) = 0
        statev(11) = 0
        statev(12) = 0
        statev(13) = 0
        statev(14) = 0
        statev(15) = 0
        statev(16) = 0

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