title: Error when trying to run simulation with Huang's UMAT using a single element
body: <p>I am trying to use Huang's UMAT (<a href="http://www.columbia.edu/%7Ejk2079/Kysar_Research_Laboratory/Single_Crystal_UMAT.html" rel="nofollow noreferrer">http://www.columbia.edu/~jk2079/Kysar_Research_Laboratory/Single_Crystal_UMAT.html</a>) in a cube element in Abaqus that I built following this tutorial: <a href="https://www.youtube.com/watch?v=9GQkNKI09ow.%C2%A0" rel="nofollow noreferrer">https://www.youtube.com/watch?v=9GQkNKI09ow. </a></p>
  <p>Every time I tried to run the simulation, Abaqus/Standard Analysis exited with an error. The message file does not exist and in the warning tab in the monitor I can read the following: &quot;The parameter hourglass = enhanced on the section controls option is relevant for these elements: c3d8r, cax4r, cgax4r, cpeg4r, cpe4r, cps4r, m3d4r, s4r, sc8r and their hybrid, thermal and pressure counterparts wherever applicable. It is also relevant for all types of modified triangular and tetrahedral elements. This warning can be ignored if the feature is applied to these element types only&quot;.</p>
  <p>The following message also appeared the first time in which I tried to run the simulations: &quot;1 elements have been defined with zero hour glass stiffness. You may use *hourglass stiffness or change the element type. The elements have been identified in element set ErrElemZeroHourGlassStiffness&quot;.</p>
  <p>It seems that the problem is related to the hourglass parameter but I was not able to find a solution yet. Could someone please help me to understand what is the problem? My goal is to run this simulation.</p>
  <pre><code>*Heading
  ** Job name: Job-1 Model name: Job-1
  ** Generated by: Abaqus/CAE 2019
  *Preprint, echo=NO, model=NO, history=NO, contact=NO
  **
  ** PARTS
  **
  *Part, name=CUBE-1
  *Node
        1,           1.,           1.,           1.
        2,           1.,           0.,           1.
        3,           1.,           1.,           0.
        4,           1.,           0.,           0.
        5,           0.,           1.,           1.
        6,           0.,           0.,           1.
        7,           0.,           1.,           0.
        8,           0.,           0.,           0.
  *Element, type=C3D8R
  1, 5, 6, 8, 7, 1, 2, 4, 3
  *Nset, nset=SET-1, generate
   1,  8,  1
  *Elset, elset=SET-1
   1,
  ** Section: Section-1-SET-1
  *Solid Section, elset=SET-1, controls=EC-1, material=MATERIAL-1
  ,
  *End Part
  **  
  **
  ** ASSEMBLY
  **
  *Assembly, name=Assembly
  **  
  *Instance, name=CUBE-1, part=CUBE-1
  *End Instance
  **  
  *Nset, nset=SET-1, instance=CUBE-1, generate
   5,  8,  1
  *Elset, elset=SET-1, instance=CUBE-1
   1,
  *Nset, nset=SET-2, instance=CUBE-1
   3, 4, 7, 8
  *Elset, elset=SET-2, instance=CUBE-1
   1,
  *Nset, nset=SET-3, instance=CUBE-1, generate
   2,  8,  2
  *Elset, elset=SET-3, instance=CUBE-1
   1,
  *Nset, nset=SET-4, instance=CUBE-1, generate
   1,  4,  1
  *Elset, elset=SET-4, instance=CUBE-1
   1,
  *End Assembly
  ** 
  ** ELEMENT CONTROLS
  ** 
  *Section Controls, name=EC-1, hourglass=ENHANCED
  1., 1., 1.
  ** 
  ** MATERIALS
  ** 
  ** COMMENTS FROM *DEPVAR
  ** =====================
  ** 
  **   ITRATN , ITRMAX , GAMERR ,
  **     --   ,   --   ,   --   ,
  **  ITRATN:  parameter determining whether iteration method is used to
  **    solve increments of stresses and state variables in terms of
  **    strain increments
  ** 
  **    ITRATN=0. --- no iteration
  **    otherwise --- iteration
  ** 
  **  ITRMAX:  maximum number of iterations
  ** 
  **  GAMERR:  absolute error of shear strains in slip systems
  ** 
  ** 
  *Material, name=MATERIAL-1
  *Depvar
      125,
  *User Material, constants=160, unsymm
  168400.,121400., 75400.,     0.,     0.,     0.,     0.,     0.
       0.,     0.,     0.,     0.,     0.,     0.,     0.,     0.
       0.,     0.,     0.,     0.,     0.,     0.,     0.,     0.
       1.,     0.,     0.,     0.,     0.,     0.,     0.,     0.
       1.,     1.,     1.,     1.,     1.,     0.,     0.,     0.
       0.,     0.,     0.,     0.,     0.,     0.,     0.,     0.
       0.,     0.,     0.,     0.,     0.,     0.,     0.,     0.
      -1.,     0.,     1.,     0.,     0.,     1.,     0.,     0.
       0.,     1.,     0.,     0.,     1.,     0.,     0.,     0.
      10.,  0.001,     0.,     0.,     0.,     0.,     0.,     0.
       0.,     0.,     0.,     0.,     0.,     0.,     0.,     0.
       0.,     0.,     0.,     0.,     0.,     0.,     0.,     0.
    541.5,  109.5,   60.8,     0.,     0.,     0.,     0.,     0.
       1.,     1.,     0.,     0.,     0.,     0.,     0.,     0.
       0.,     0.,     0.,     0.,     0.,     0.,     0.,     0.
       0.,     0.,     0.,     0.,     0.,     0.,     0.,     0.
       0.,     0.,     0.,     0.,     0.,     0.,     0.,     0.
       0.,     0.,     0.,     0.,     0.,     0.,     0.,     0.
      0.5,     1.,     0.,     0.,     0.,     0.,     0.,     0.
       1.,    10.,  1e-05,     0.,     0.,     0.,     0.,     0.
  ** ----------------------------------------------------------------
  ** 
  ** STEP: Step-1
  ** 
  *Step, name=Step-1, nlgeom=YES
  *Static
  0.5, 1., 1e-05, 1.
  ** 
  ** BOUNDARY CONDITIONS
  ** 
  ** Name: Disp-BC-1 Type: Symmetry/Antisymmetry/Encastre
  *Boundary
  SET-1, XSYMM
  ** Name: Disp-BC-2 Type: Symmetry/Antisymmetry/Encastre
  *Boundary
  SET-2, ZSYMM
  ** Name: Disp-BC-3 Type: Symmetry/Antisymmetry/Encastre
  *Boundary
  SET-3, YSYMM
  ** Name: Disp-BC-4 Type: Displacement/Rotation
  *Boundary
  SET-4, 1, 1, 0.001
  ** 
  ** OUTPUT REQUESTS
  ** 
  *Restart, write, frequency=0
  ** 
  ** FIELD OUTPUT: F-Output-1
  ** 
  *Output, field, variable=PRESELECT
  ** 
  ** HISTORY OUTPUT: H-Output-1
  ** 
  *Output, history, variable=PRESELECT
  *End Step
  
  </code></pre>
  <p>Thank you very much for your help.</p>