MYSTRANsolver
PCOMP strange deflection
New bug in the current version but not 15.2 or 15.1.1
Due to symmetry, displacement should be equal on grid points 3 and 4 like this (15.2.1)
D I S P L A C E M E N T S
(in global coordinate system at each grid)
GRID COORD T1 T2 T3 R1 R2 R3
SYS
1 0 0.0 0.0 0.0 0.0 0.0 0.0
2 0 0.0 0.0 0.0 0.0 0.0 0.0
3 0 4.135609E-11 3.654794E-09 -2.327970E-08 -4.511165E-07 -2.060003E-10 0.0
4 0 4.254528E-11 3.696704E-09 -2.327957E-08 -4.511129E-07 2.234854E-10 0.0
but they're different in 16.0.0, especially T3 and R1:
D I S P L A C E M E N T S
(in global coordinate system at each grid)
GRID COORD T1 T2 T3 R1 R2 R3
SYS
1 0 0.0 0.0 0.0 0.0 0.0 0.0
2 0 0.0 0.0 0.0 0.0 0.0 0.0
3 0 -4.263561E-10 3.674017E-09 -2.181930E-08 -4.167108E-07 -2.835766E-08 0.0
4 0 -5.360208E-10 3.956977E-09 -2.519216E-08 -5.198202E-07 -5.054554E-08 0.0
SOL 101
CEND
DISPLACEMENT = ALL
FORCE = ALL
SPC = 1
LOAD = 1
BEGIN BULK
GRID* 1 0 0. 0.9*
* 0. 0
GRID* 2 0 0.05 0.9*
* 6.9388939-18 0
GRID* 3 0 0.05 1.*
* 6.9388939-18 0
GRID* 4 0 0. 1.*
* 0. 0
$--1---><------2-------><------3-------><------4-------><------5-------><--6--->
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ Material $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
MAT8* 1 1.+11 1.+11 0.*
* 5.+10 5.+10 5.+10 0.*
* 0. 0. 0. *
*
MAT8* 2 1.+10 1.+10 0.*
* 5.+09 5.+09 5.+09 0.*
* 0. 0. 0. *
*
$--1---><------2-------><------3-------><------4-------><------5-------><--6--->
SPC* 1 1 1 0.*
*
SPC* 1 1 2 0.*
*
SPC* 1 1 3 0.*
*
SPC* 1 1 4 0.*
*
SPC* 1 1 5 0.*
*
SPC* 1 1 6 0.*
*
SPC* 1 2 1 0.*
*
SPC* 1 2 2 0.*
*
SPC* 1 2 3 0.*
*
SPC* 1 2 4 0.*
*
SPC* 1 2 5 0.*
*
SPC* 1 2 6 0.*
*
$--1---><------2-------><------3-------><------4-------><------5-------><--6--->
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ Default $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
PCOMP* 1 *
* 0. *
* 1 0.01 0. *
* 2 0.01 0.
CQUAD4* 1 1 4 1*
* 2 3 0. 0.
$--1---><------2-------><------3-------><------4-------><------5-------><--6--->
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ force $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
FORCE* 1 4 0 1.*
* 0. 0.5 0.
FORCE* 1 3 0 1.*
* 0. 0.5 0.
$--1---><------2-------><------3-------><------4-------><------5-------><--6--->
ENDDATA
Turns out it's an old bug in MIN4 but works OK with MIN4T. It didn't appear in 15.2 because MIN4T was the default.
Can be fixed for MIN4 by setting PARAM,IORQ2T,2 instead of the default 3. Maybe this should be the default, at least for non-symmetric composites.
MIN4T does have a problem though.
This seems to have been accidentally fixed somehow and it's no longer a problem even with the default IORQ2T = 3.
