Learning Forum

[Raghav]

Hello everyine,

I am modelling a composite with 0/90 lamina orientation for high velocity impacts. I have used CONTACT_SURFACE_TO_SURFACE_TIEBREAK between 0 and 90 sublamina, each with 0.5 mm thickness (total thickness of composite is 8 mm). This contact is modelled using option 9 with normal and shear strength as input. the solid section uses ELFORM=2 and while impact eroding surface to surface contact has been chossen.

While running the program, it is showing me following error:-

Error 40559 (SOL+559)

Contact node 152 using tiebreak failure option 9/11 has inconsistent material properties resulting in a negative displacement for the peak traction for mixed mode loading. Increase energy release rates or stiffness, or decrease peak stresses. More informations about this error check can be found in the Users Manual on Material Models, see *MAT_138.

Is it because the change of material properties (orientation of fibers)? How can I solve this error.

Regards

[igandiko]

Hello, 

Please try adjusting the scale factors on both penalty stiffness terms on the card. If you're using curves to defined normal and shear failure stresses, please set NFLS and SFLS to positive values (just as an experiment) so the normal and shear failure stresses are constants and not a function of element size. Perhaps this will help to isolate the problem with your input. 

Note that there are certain internal checks that are performed on *contact_automatic_..._tiebreak, option 9. These checks are similar to internal checks done for mat_138. Please see user manual of this materialer model and try to do those checks yourself.