debonding-cohesive zone modeling - abaqus- traction separation element
debonding-cohesive zone modeling - abaqus- traction separation element
(OP)
Could any one please guide me how can I simulate the debonding behaviour (traction sepration elements) of the two cylinder type models in ABAQUS. It will be a life saving help from you.
Thank you!!!!
Regards
Thank you!!!!
Regards





RE: debonding-cohesive zone modeling - abaqus- traction separation element
I think you have to code the user subroutine UEL to implement a CZM element.
Also, it might be helpful to take a look at
ABAQUS Analysis User's Manual ->7.9.3 Crack propagation analysis
for the ABAQUS built-in way to simulate surface debonding.
RE: debonding-cohesive zone modeling - abaqus- traction separation element
Also, which version of the Abaqus manual, you are suggesting?? ABAQUS Analysis User's Manual ->7.9.3 Crack propagation analysis
Thank you!!!
RE: debonding-cohesive zone modeling - abaqus- traction separation element
I was referring to the v6.4 manuals.
RE: debonding-cohesive zone modeling - abaqus- traction separation element
in :
ABAQUS/CAE user's manual (v.6.5)
21.1 Modeling adhesive joints and bonded interfaces
???
I built a 3 part model in 2D , actually 2 parts and
a the 3rd very thin used for the interface. I meshed the interface with 1 row of cohesive elements.
It worked without any problem.
RE: debonding-cohesive zone modeling - abaqus- traction separation element
I have spent more than one month in this...but still could not.....
If you like, I can send you my input file.
Regards
RE: debonding-cohesive zone modeling - abaqus- traction separation element
For example you said
If it does not work , do you get some error messages ?
Is you model 3D or axissymetric ? What type(s) of element
do you use in your model ?
...and so on.
RE: debonding-cohesive zone modeling - abaqus- traction separation element
Due to the complicated geomtetries, I am using linear tetrahedral fine meshes. for the cohesive zone, i am assigning "cohesive elements" with traction separation method.
The error it says "...node number might not be correct for ... element..."
RE: debonding-cohesive zone modeling - abaqus- traction separation element
RE: debonding-cohesive zone modeling - abaqus- traction separation element
I am using ORPHAN mesh (created from the already existing parts). COH3D8 is the element type I am uing on the cohesive zone.
RE: debonding-cohesive zone modeling - abaqus- traction separation element
RE: debonding-cohesive zone modeling - abaqus- traction separation element
Please help me in this regard!!!!
RE: debonding-cohesive zone modeling - abaqus- traction separation element
For modeling I used CAE , but I did not create orphan meshes, I just used the geometric parts. In this way is much easier to define the surfaces based on geometric entities.
In both case I used 2 parts separated by a small interface part.Thus, I modeled the interface as a thin separate geometric part.
In the 3D case I modeled 2 concentric cylinders ( 5 and 10 mm thick, respectively) separated by the interface part about 0.01 mm thick. I assigned a cohesive section to the interface part (response=Traction Separation, initial thickness=Use nodal coordinates).
For the main parts I assigned a different isotropic elastic material and ELASTIC, TYPE=TRACTION for the interface constitutive response:
** MATERIALS
**
*Material, name=Material-inner
*Elastic
210000., 0.3
*Material, name=Material-interface
*Elastic, type=traction
1000,200,200,0
*Material, name=Material-outer
*Elastic
300000., 0.3
I had to adjust the definition of interface material with the Keyword editor.
For the interface part I used "Sweep" technique for the meshing algorithm.
I constrained the interface part to the cylinders by creating surfaces and using the TIE constraint (i.e., 2 constraints).
Otherwise, nothing special.
RE: debonding-cohesive zone modeling - abaqus- traction separation element
By the way, you did it in Standard (Implicit) or in Explicit?
Thank you!!
RE: debonding-cohesive zone modeling - abaqus- traction separation element
RE: debonding-cohesive zone modeling - abaqus- traction separation element
*Material, name=Post
*Elastic
116000., 0.33
*Material, name=cohesive
*Elastic, type=traction
1000000,1000000,1000000
**i varied this 100000 ...from 1000 to this value....
*Material, name=Cement
*Elastic
22000., 0.35
also used the TIE constraints....
all the parts are meshed using SWEEP algorithm.
post element - c3d8r
cement element - c3d8r
cohesive element - coh3d8
seeding size - 2 unit
Please save me.....
RE: debonding-cohesive zone modeling - abaqus- traction separation element
A better technique (for v6.5... In V6.6 there is a very very easy way to do this with no need for orphan meshes!) is to use the manual mesh edit tools to extrude element faces normal to the underlying mesh, thus creating "layers" of wedge or brick elements. Assign the correct element type (SC6R / SC8R) and then assign the shell section to these. By the way, you'll make your life a lot easier if you create named sets for your cohesive layers...
BTW you should use the Tools-Query-"Mesh Stack Orientation" to ensure you have the elements oriented consistently!
Good luck. If you need more help I'd be happy to post a script to demonstrate some of what I'm talking about.
RE: debonding-cohesive zone modeling - abaqus- traction separation element
[URL=http://www.zshare.net/download/tooth-py.html]tooth.py - 0.02MB[/URL]
Hope you like it!
RE: debonding-cohesive zone modeling - abaqus- traction separation element
I was doing the same "orphan mesh" techniqu to generate the layers of cohesive elements. instead of shell elements SC8R elements i am using the cohesive elements coh3d8...it seems my mesh orientation is ok. but still i dont know what should i do.......not able to run the problem...
RE: debonding-cohesive zone modeling - abaqus- traction separation element
Do you get this for the very first increment ?
First, you could try to adjust the time incrementation parameters, i.e. in the Step option:
- set the initial increment size to a small value, say 0.01
- set the minimum increment size to let say 1.e-9
Second, make sure the loadings (whatever their type is) are ramped and not applied instantaneously.
What do you mean by
"seeding size - 2 unit" ?
The global seed size ?
If is that, given that the cylinders are 1 and 1.5 mm thick,
then do you have just a layer of elements for each cylinder ? Actually I think so since you used SWEEP for each part.
RE: debonding-cohesive zone modeling - abaqus- traction separation element
the initial increment time is 0.01 and also i put increment size as 1e-20.
Also the load is
time - load
0-0
0.5-5
1-10.25
but still i get the same error "too....increment"
the global seeding size is 2.
I also changed the meshing technique from SWEEP to the FREE meshing, but still the same problem....
RE: debonding-cohesive zone modeling - abaqus- traction separation element
RE: debonding-cohesive zone modeling - abaqus- traction separation element
how do you assemble the orphan meshes of two concentric cylinders? Why cant I use the assembly-constrain-coaxial to put the concentric cylinder's orphan meshes?
Thanks
RE: debonding-cohesive zone modeling - abaqus- traction separation element