HIGH MATRIX/FACTOR DIAGONAL RATIO

[janipk]

Hello to everyone,

I am running a nonlinear analysis on Nastran using CBEAM as rivets and CGAP elements and have very high (10E+9) or negative MATRIX/FACTOR DIAGONAL RATIOs(high rotations at nodes) at the nodes of CBEAM elements. Does anyone know how control the high rotations on these noeds?

Hoping to get some useful suggestions from kind people.

Regards,

 

[janipk]

Hi,

I have already used K6ROT parameter to control the R1 but I have problem with R2 and R3.

regards,

 

[ThomasH]

Hi

Try running a eigenfrequency analysis. That might give you hints so you can see if any parts are not properly constrained.

Good Luck

Thomas