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NX Nastran Gap element not working as intended

NX Nastran Gap element not working as intended

NX Nastran Gap element not working as intended

(OP)
I am running a simple model. Gave enforced displacement on top plate (in the direction perpendicular to the plate). Defined a 1D gap element between the two plates. Fixed the bottom plates away on the perimeter a few nodes away from where the gap element attaches on the lower plate.

The gap element is ignored by soln 101 and soln 106. Does it happen this way? The gap element is not working in this case.I am attaching the nastran file.

^^^CONTACT ITERATION NUMBER 8
^^^
*** USER WARNING MESSAGE 4690 (FOCOSTT)
ALL CONTACT ELEMENTS HAVE BECOME INACTIVE. THE STIFFNESS MATRIX MAY
BECOME SINGULAR WHICH WILL RESULT IN ERRORS FURTHER IN THE ANALYSIS
^^^
^^^NUMBER OF CONTACT STATUS CHANGES: 0
^^^NUMBER OF INACTIVE CONTACTS: 1
^^^NUMBER OF ACTIVE OPEN CONTACTS: 0
^^^NUMBER OF STICKING CONTACTS: 0
^^^NUMBER OF SLIDING CONTACTS: 0
^^^
^^^CONTACT ITERATION CONVERGED

For soln 101, I gave the following in the nastran file.
________________________________________________________

SOL 101
CEND

BCSET=1
$ NLPARM =101
ANALYSIS = STATICS
DISPLACEMENT(PLOT) = ALL
STRESS(PLOT) = ALL

SUBCASE2
LABEL= neg_load
SPC = 6
LOAD = 4
$$------------------------------------------------------------------------------$
$$ Bulk Data Cards $
$$------------------------------------------------------------------------------$
BEGIN BULK
PARAM, CDITER,12
PARAM,AUTOSPC,YES
PARAM,K6ROT,100.0
PARAM,MAXRATIO,1.0+9
PARAM,POST,-2
BCTPARM,1,CSTRAT,1,RESET,1,NCHG,0
......
......
......

NLPARM 101 1000.0 AUTO 5 25 PWU NO
+ 0.01 0.01 0.001 3 25 40.2 0.5
+ 5 20.0 20.0

SPCADD 6 4 1 2
$
$$
$$ SPC Data
$$
SPC 1 5904071 1234560.0
SPC 1 5904070 1234560.0
SPC 1 5904069 1234560.0
SPC 1 5904035 1234560.0
SPC 1 5904072 1234560.0
SPC 1 5904073 1234560.0
SPC 1 5904074 1234560.0
SPC 1 5904075 1234560.0
SPC 1 5904076 1234560.0
SPC 1 5904077 1234560.0
SPC 1 5904078 1234560.0
SPC 1 5904672 1234560.0
SPC 1 5904743 1234560.0
SPC 1 5904744 1234560.0
SPC 1 5904745 1234560.0
SPC 1 5904746 1234560.0
SPC 1 5904874 1234560.0
SPC 1 5904875 1234560.0
SPC 1 5904876 1234560.0
SPC 1 5904877 1234560.0
SPC 1 5904878 1234560.0
SPC 1 5909979 1234560.0
SPC 1 5909986 1234560.0
SPC 1 5909988 1234560.0
SPC 1 5909991 1234560.0
SPC 1 5909992 1234560.0
SPC 1 5909995 1234560.0
SPC 1 5909996 1234560.0
SPC 1 5910001 1234560.0
SPC 1 5910002 1234560.0
SPC 1 5925323 12456 0.0
SPC 1 5925324 1234560.0
SPC1 2 3 592532
$$
$$ SPCD Data
$$
SPCD 4 5925323 3 -0.25
END
_____________________________________________________

RE: NX Nastran Gap element not working as intended

(OP)
Here is how I defined gap element and its property....

CGAP 6258437 103957 5925321 59252910.0 0.0 1.0 0
PGAP 1039550.0 1.0+8 0.0 0.0 0.0

RE: NX Nastran Gap element not working as intended

(OP)
It works when the direction for the gap element is removed.

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