element failed before failure criterion is met

- June 10, 2020 at 2:45 pm
  
  kugg2116
  Subscriber
  
  When I used a single element to test the model JH2 (mat 110) in LS-DYNA (see k file below), the element failed abruptly at some point before the failure criterion was met. This might lead to an underestimated load bearing capacity. I have tried different element formulation, hourglass control, but still couldn’t fix it.
  
  The stress curve is shown below in green, the red curve is pressure. The second figure is the result I got from ABAQUS for the same problem. As you can see, initially, the two results are very close. The difference lies in that the element in LS-DYNA failed around 0.3s.
- June 10, 2020 at 3:02 pm
  
  kugg2116
  Subscriber
  
  *KEYWORD
  
  *TITLE
  
  *CONTROL_TERMINATION
  
  3.0 0 0.0 0.01.000000E8 0
  
  *CONTROL_TIMESTEP
  
  0.0 0.6 0 0.0 0.0 0 0 0
  
  0.0 0 0 0.0
  
  *DATABASE_GLSTAT
  
  0.002 3 0 1
  
  *DATABASE_MATSUM
  
  0.02 0 0 1
  
  *DATABASE_SLEOUT
  
  0.02 3 0 1
  
  *DATABASE_BINARY_D3PLOT
  
  0.002 0 0 0 0
  
  0
  
  *BOUNDARY_PRESCRIBED_MOTION_SET
  
  2 3 2 1 1.0 01.00000E28 0.0
  
  *BOUNDARY_SPC_SET_ID
  
  0Bottom
  
  1 0 1 1 1 1 1 1
  
  *SET_NODE_LIST_TITLE
  
  Bottom
  
  1 0.0 0.0 0.0 0.0MECH
  
  4 1 2 3 0 0 0 0
  
  *BOUNDARY_SPC_SET_ID
  
  0Top
  
  2 0 0 0 0 0 0 0
  
  *SET_NODE_LIST_TITLE
  
  Top
  
  2 0.0 0.0 0.0 0.0MECH
  
  6 5 8 7 0 0 0 0
  
  *PART
  
  Single_Elem_JH2
  
  3 2 1 0 1 0 0 0
  
  *SECTION_SOLID_TITLE
  
  Solid section EQ1 RI
  
  2 1 0
  
  *MAT_JOHNSON_HOLMQUIST_CERAMICS_TITLE
  
  SiC_abaqusExample
  
  13.21500E-9 193000.0 0.96 0.35 0.009 1.0 0.65
  
  1.0 750.0 0.0 11700.0 5130.0 1.0
  
  0.48 0.48 220000.0 361000.0 0.0 0.2
  
  *HOURGLASS
  
  1 4 0.03 0 1.5 0.06 0.1 0.1
  
  *DEFINE_CURVE_TITLE
  
  Downward_displacement
  
  1 0 1.0 1.0 0.0 0.0 0 0
  
  0.0 0.0
  
  1.0 -5.0
  
  2.0 0.0
  
  3.0 5.0
  
  *DAMPING_GLOBAL
  
  0 0.1 0.0 0.0 0.0 0.0 0.0 0.0
  
  *ELEMENT_SOLID
  
  1 3 1 2 3 4 5 6 7 8
  
  *NODE
  
  1 0.0 0.0 0.0 0 0
  
  2 100.0 0.0 0.0 0 0
  
  3 100.0 100.0 0.0 0 0
  
  4 0.0 100.0 0.0 0 0
  
  5 0.0 0.0 100.0 0 0
  
  6 100.0 0.0 100.0 0 0
  
  7 100.0 100.0 100.0 0 0
  
  8 0.0 100.0 100.0 0 0
  
  *END

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