Hello,,,,,,Everyone
i m modeling a delamination buckling of composite laminates using cohesive element I M USING ABAQUS STANDARD 6.14 FOR MODELING,,,Model description is like this
IT have two laminates upper(having 4 plies/thinner laminate) and lower laminates(36 plies/thicker lamina) in between the is a 10x10 pre delamination region and a cohesive element has been inserted between these laminates to predict the propegation of delamination,,
DUE TO SYMMETRY i model only quarter of the model,,, after applying a force it should buckle from the pre delamination from the tip and goes down
while in my model it does NOT open from here at first but from the opposite corner ,,,,also there is penetration at the square shape delamination location
can any one help me why is it not opening correctly from correct location ,,here is the picture and paper i m using as a reference paper..
any suggestion would be appreciated i can send u the cae file too if some one want to take a look at it
thank u
BEST REGARDS
Check your boundary conditions on the symmetry planes. You might have accidently applied a zero displacement BC in the z direction on the symmetry plane, which prevents the correct opening.
Have you applied a contact relationship between the two faces of the laminate in the unbonded region?
hello Reuben Govender
thanks for ur response ..i double checked my boundry condition are same as shown in the attached file,,,
yes sir i create frictionless contact definition in the delamination region laminates,,,but they still penetrates if i prevent that some how by using penalty stifness of 850mpa ,,the penetration then occure between the laminates and cohesive elements,,i would be glade if u could suggest to prevent this penetration and also that might be the reason of incorrect opening,,,
thanks best regards
What is your definition for the normal contact. Also, are you using surface to surface or surface to nodal region, small or finite sliding? Please verify the scale factor, set it to 1. Sometimes, the scale factor shows an unrealistic situation.
thank u Marclo Leite RIbeiro..
i m using surface to surface contact with finite sliding
normal contact with penalty method and using a value of penalty stiffness 850
Dear Ismail,
The best way to prevent penetration is by using node to surface contact ant finite sliding. The most important issue in your model is the symmetry. The symmetry is correct just for 0,90 stack sequence because 45 ply is not symmetry even the boundary condition is symmetry. Check that.
Regards
- Badges
- Science topic