Skysurfer76
Structural
- Apr 20, 2008
- 4
Hello!
I have the wing copmosite panel that consists of honeycomb panel itself (modeled by mean of laminate elements) and brackets (that is modeled by mean of plate elements). Brackets and panel connected via cweld elements. Load is pressure on panel. Constraints are on brackets.
Static analysis is ok. But when I run nonlinear static analysis (106) I receive UWM 4896:
*** USER WARNING MESSAGE 4698 (DCMPD)
STATISTICS FOR DECOMPOSITION OF MATRIX KLLRH .
THE FOLLOWING DEGREES OF FREEDOM HAVE FACTOR DIAGONAL RATIOS GREATER THAN
1.00000E+08 OR HAVE NEGATIVE TERMS ON THE FACTOR DIAGONAL.
USER INFORMATION:
THIS MESSAGE MAY BE IGNORED IF NO GRID POINT IDS OR
...........................
User's Guide.
1 P=-2460 FI=0 APRIL 20, 2008 NX NASTRAN 1/29/07 PAGE 9
GRID POINT ID DEGREE OF FREEDOM MATRIX/FACTOR DIAGONAL RATIO MATRIX DIAGONAL
4421 T3 -4.96299E+02 3.34151E+04
4439 T3 -1.16222E+02 2.36758E+04
4448 T1 -3.96610E+01 6.78013E+03
4461 T3 -2.29087E+03 5.31481E+03
4483 T3 -2.07175E+01 5.21180E+03
4596 R3 -3.46916E+01 6.69773E+03
4700 T3 -6.99364E+02 6.76800E+03
4703 T3 -3.41159E+03 6.79904E+03
5050 R1 -1.48623E+01 6.31438E+03
^^^ USER INFORMATION MESSAGE 9004 (NLSTATIC)
^^^ FOR THIS ITERATION, THE DIFFERENTIAL STIFFNESS WILL BE IGNORED TO AVOID DECOMPOSITION OF A NON-POSITIVE
DEFINITE STIFFNESS MATRIX.
Then solution reaches load step 1.0 and when output listing begins such messages occurs:
MAIN: The FPU has been reset after floating point exception.
MAIN: For reference, A(MAINAL) = 4012B0, A(/SYSTEM/) = 1C930C0
MAIN: A(/XNSTRN/) = 39E0020
MAIN: "Floating point overflow" (C0000091) exception encountered.
MAIN: Exception occurred at address 017838C8.
MAIN: Context Flags 0001003F
MAIN: EAX 00000001 EBX 0012F380 ECX 000000C1 EDX 00000000 ESI 00000001 EDI 00000004
MAIN: EBP 00000000 ESP 0012F340 EIP 017838CF EFLAGS 00010202
I've tried to do eigenvalue analysis - it's ok. The model is constrained properly. Also I checked mesh quality - it's ok.
But most strange thing is when I deleted a part of one bracket solution ended correctly. And when I meshed that part again this error occured. But definitely, the point is not in this part, because mesh is good.
And even when I constrained all separate parts of my model this error occurs again!
Also I tried to replace cweld elements with RBE2 - no effect.
Is there any ideas about this?
Thanks in advance
I have the wing copmosite panel that consists of honeycomb panel itself (modeled by mean of laminate elements) and brackets (that is modeled by mean of plate elements). Brackets and panel connected via cweld elements. Load is pressure on panel. Constraints are on brackets.
Static analysis is ok. But when I run nonlinear static analysis (106) I receive UWM 4896:
*** USER WARNING MESSAGE 4698 (DCMPD)
STATISTICS FOR DECOMPOSITION OF MATRIX KLLRH .
THE FOLLOWING DEGREES OF FREEDOM HAVE FACTOR DIAGONAL RATIOS GREATER THAN
1.00000E+08 OR HAVE NEGATIVE TERMS ON THE FACTOR DIAGONAL.
USER INFORMATION:
THIS MESSAGE MAY BE IGNORED IF NO GRID POINT IDS OR
...........................
User's Guide.
1 P=-2460 FI=0 APRIL 20, 2008 NX NASTRAN 1/29/07 PAGE 9
GRID POINT ID DEGREE OF FREEDOM MATRIX/FACTOR DIAGONAL RATIO MATRIX DIAGONAL
4421 T3 -4.96299E+02 3.34151E+04
4439 T3 -1.16222E+02 2.36758E+04
4448 T1 -3.96610E+01 6.78013E+03
4461 T3 -2.29087E+03 5.31481E+03
4483 T3 -2.07175E+01 5.21180E+03
4596 R3 -3.46916E+01 6.69773E+03
4700 T3 -6.99364E+02 6.76800E+03
4703 T3 -3.41159E+03 6.79904E+03
5050 R1 -1.48623E+01 6.31438E+03
^^^ USER INFORMATION MESSAGE 9004 (NLSTATIC)
^^^ FOR THIS ITERATION, THE DIFFERENTIAL STIFFNESS WILL BE IGNORED TO AVOID DECOMPOSITION OF A NON-POSITIVE
DEFINITE STIFFNESS MATRIX.
Then solution reaches load step 1.0 and when output listing begins such messages occurs:
MAIN: The FPU has been reset after floating point exception.
MAIN: For reference, A(MAINAL) = 4012B0, A(/SYSTEM/) = 1C930C0
MAIN: A(/XNSTRN/) = 39E0020
MAIN: "Floating point overflow" (C0000091) exception encountered.
MAIN: Exception occurred at address 017838C8.
MAIN: Context Flags 0001003F
MAIN: EAX 00000001 EBX 0012F380 ECX 000000C1 EDX 00000000 ESI 00000001 EDI 00000004
MAIN: EBP 00000000 ESP 0012F340 EIP 017838CF EFLAGS 00010202
I've tried to do eigenvalue analysis - it's ok. The model is constrained properly. Also I checked mesh quality - it's ok.
But most strange thing is when I deleted a part of one bracket solution ended correctly. And when I meshed that part again this error occured. But definitely, the point is not in this part, because mesh is good.
And even when I constrained all separate parts of my model this error occurs again!
Also I tried to replace cweld elements with RBE2 - no effect.
Is there any ideas about this?
Thanks in advance