input A B D E F matrix for SHELL99

- May 11, 2024 at 5:02 am
  
  fang pc
  Subscriber
  
  I have some problems when using shell99 element keyopt2,3, I input A B D E F matrix, and ensure that they are positive definite, but when calculating, ansys prompts an error,
  *** ERROR *** CP = 9.406 TIME= 10:53:01
  Input matrix of element 1 is not positive semi-definite. Check real
  constant table 1.
  how to solve it
  Here's what I wrote about apdl
  /prep7
  ESEL,s,elem,, 1, 1, 1600
  ET, 1,99
  KEYOPT, 1,2,3
  R, 1, 0.10000000E+12
  RMODIF, 1,2, 0.91158854E+02
  RMODIF, 1,4, 0.21316282E-13
  RMODIF, 1,7, 0.10000000E+11
  RMODIF, 1,9, 0.26645353E-14
  RMODIF, 1,12, 0.10000000E+11
  RMODIF, 1,16, 0.10000000E+11
  RMODIF, 1,19, 0.10000109E+11
  RMODIF, 1,21, 0.10000109E+11
  RMODIF, 1,22, 0.10000002E+10
  RMODIF, 1,23, -0.68903426E+02
  RMODIF, 1,25, 0.94291151E+02
  RMODIF, 1,28, 0.99999998E+09
  RMODIF, 1,30, 0.38613569E+02
  RMODIF, 1,33, 0.10000000E+10
  RMODIF, 1,37, 0.99999993E+09
  RMODIF, 1,40, 0.99993110E+09
  RMODIF, 1,42, 0.99993110E+09
  RMODIF, 1,43, 0.10000000E+11
  RMODIF, 1,44, 0.43756250E+02
  RMODIF, 1,46, 0.52558450E+01
  RMODIF, 1,49, 0.10000000E+11
  RMODIF, 1,51, 0.68758909E+00
  RMODIF, 1,54, 0.10000000E+11
  RMODIF, 1,58, 0.10000000E+11
  RMODIF, 1,61, 0.10000052E+11
  RMODIF, 1,63, 0.10000052E+11
  RMODIF, 1,64, 0.10000005E+10
  RMODIF, 1,65, -0.19689154E+03
  RMODIF, 1,67, -0.52614462E+03
  RMODIF, 1,70, 0.99999994E+09
  RMODIF, 1,72, -0.21546371E+03
  RMODIF, 1,75, 0.10000000E+10
  RMODIF, 1,79, 0.99999980E+09
  RMODIF, 1,82, 0.99980311E+09
  RMODIF, 1,84, 0.99980311E+09
  RMODIF, 1,85, 0.10000000E+11
  RMODIF, 1,86, 0.37805400E+02
  RMODIF, 1,88, 0.14545551E+02
  RMODIF, 1,91, 0.10000000E+11
  RMODIF, 1,93, 0.19029028E+01
  RMODIF, 1,96, 0.10000000E+11
  RMODIF, 1,100, 0.10000000E+11
  RMODIF, 1,103, 0.10000045E+11
  RMODIF, 1,105, 0.10000045E+11
  RMODIF, 1,125, 0.24000000E+01
  EMODIF,ALL,REAL, 1
  EMODIF,ALL,TYPE, 1
- May 11, 2024 at 5:08 am
  
  Long Song
  Subscriber
  
  I met the same problem.
- May 20, 2024 at 2:01 pm
  
  Ashish Khemka
  Forum Moderator
  
  Hi,
  Which version of Ansys are you using? SHELL99 is no longer supported in the current version.
  Regards,
  Ashish Khemka
  - May 23, 2024 at 8:29 am
    
    fang pc
    Subscriber
    
    Thank you for your answer. I am using version ANSYS191. By the way, may I ask which element should be used to replace the current version
- May 23, 2024 at 9:01 am
  
  Ashish Khemka
  Forum Moderator
  
  You can try Shell 281.
  Regards,
  Ashish Khemka
  - May 24, 2024 at 3:05 am
    
    fang pc
    Subscriber
    
    Thank you for your answer. If I continue to use shell99, can you solve the problem of my input matrix? Or the new version which element can input the matrix