hello,all ! recently i try to use cohesive element to analyse interface damage .but i have trouble in creating cohesive element with python.hope that all give me some recommendation such as books,codes or others.thanks
Dear Ge,
Prof. Paulino in Georgia Tech has developed a UEL subroutine for Abaqus
to implement cohesive elements.
It is available and well documented:
https://paulino.ce.gatech.edu/PPR_tutorial.html
Developing a UEL subroutine, in which you add an additional degree of freedom
to the nodes to represent debonding, is the only way I know to implement cohesive elements in Abaqus.
So, I am not sure what you mean by "cohesive element created in python".
Hope this helps,
Best Regards,
Nicolò
The question is (relatively) old, so maybe Ge Jian already found the solution, but the answer may become of some use for other Abaqus users. First, a few considerations.
Nicolò Grilli Cohesive elements have been provided as built-in elements in Abaqus for many years, around 10-15. Cohesive elements were first formulated and proposed by Davila, Camanho, and Turon at the beginning of the 2000s and implemented as UEL in Abaqus. Following a growing interest in the simulation community, particularly those interested in laminated composite materials, Abaqus embraced their formulation and included cohesive elements in the standard library. So no, you do not need to write a UEL or UMAT to use cohesive elements. You need to write a UEL only if you are interested in using a specific cohesive law, usually in relation to non-linear behavior in the loading and/or more often in the softening part of the law. Many proposals exist in the literature, as far back as the 1950s (see Barenblatt,
The formation of equilibrium cracks during brittle fracture, 1959). What Prof. Paulino proposes (and which I find very interesting) is a way of finding cohesive laws starting from a thermodynamically consistent potential formulation. Thence the need to use UEL.
He Hu Indeed cohesive elements are provided as part of the standard element library in Abaqus, but this is completely unrelated to the use of Python and does not make it useless. Python is desirable or even needed in the case a large degree of automation is required and many variations of a model are to be analyzed. So, the fact that cohesive elements are provided in the Abaqus standard library does not mean that Python is not needed.
To get back to the answer, it took me a while to understand how to insert cohesive elements using the Python API. Here's my take.
1. During Part creation, create a Sketch if one doesn't already exist and partition the geometry. You need to create an additional section located at the interface where cohesive elements should be placed. If the initial thickness of cohesive elements is meant to be zero, it is to be set as a Section property.
2. During Mesh creation, assign cohesive elements to the interface region.
Details can be found in the manual, for example:
https://abaqus-docs.mit.edu/2017/English/SIMACAECAERefMap/simacae-t-prpsectioncohesive.htm
I'm about to write a Python code to mesh with cohesive elements. I will post snippets of the code as soon as they are available.
- Badges
- Science topic
- Similar topics
- Computer Science and Engineering
- Programming Languages
- Python