A free program to generate interface elements in an existing FE mesh

vinh phu nguyen's picture

Hello all,

Last year when I started implementing interface elements to model material failure, I realized that the formulation is easy except how to generate a mesh with interface elements. I did a googling to search for such a free program. Amazingly, I did not find any although there are many researchers working on the fracture mechanics field. 

So, I wrote a small object-oriented C++ program which reads a FE mesh, duplicates nodes and insert interface elements where asked. The program is able to 

(1) insert 1D/2D interface elements everywhere in a FE mesh

(2) insert i1D/2D nterface elements along material interfaces, useful for delamination analysis or interface debonding

(3) insert 1D/2D interface elements along grain boundaries for a pollycrytalline solid, useful for inter-granular crack modelling in pollycrystals.

The program is written in such a way that any FE mesh format is supported. Currently only Gmsh format is however implemented. Some examples are given below.

 

 

If you are interested in this program, feel free to email me, nvinhphu@gmail.com. I will find a place to put it on the web.

Thanks.


Lianhua Ma's picture

Hi Nguyen, the code you

Hi Nguyen, the code you mention may be convenient to generate interface meshes in open source FE software.  I think it is also easy to generate such meshes in ANSYS or ABAQUS.

I have one question for the simulation of material interfacial failure.

Is it possible to model the failure of the interface between the solid and shell model by zero thickness interface element?

Thanks

Lianhua 

 

 


vinh phu nguyen's picture

Hi Lianhua, Could you be

Hi Lianhua,

Could you be more specific please? I din't get your point, sorry.

 Phu


Lianhua Ma's picture

Hi Phu, I am sorry I did

Hi Phu, I am sorry I did not give more details about my question.  I’m trying
to make it clear in this post.


In the commercial FE software(ANSYS or ABAQUS), as we know, most composite models (matrix
and inclusion) are generally constructed using
(2D or 3D) solid elements for all parts. In such cases, we need to generate interface elements as you mentioned when modeling material failure behavior. I think this can be easily implemented in ABAQUS.  


Now let’s consider a special kind of composite, carbon nanotube(CNT)-reinforced
composite, to simplify we can treat CNT as a shell model(which has already developed
in some literatures). In this case, the matrix and CNT can be modeled respectively
by solid and shell elements in ABAQUS. I am currently interested in the interfacial
failure issue of this model. Using your program, could you generate corresponding
interface elements for this model? Could you give more information about the
special cohesive interface failure simulation?

Thanks

Lianhua


vinh phu nguyen's picture

Hi Lianhua, My interface

Hi Lianhua,

My interface element model is able to deal with solid-solid interfacial failure. My interface elements generator howver just reads a FE mesh and insert interface elements where necesarry. It does not know about solid or shell elements.

I leave your question on failure model for solid/shell interface to experts on this field. Sorry for not being so helpful.

Phu 


Hi Phu,  Abaqus provide a

Hi Phu,

 Abaqus provide a kind of element name cohesive, which can simulate interface between solid and solid. Can you describe your program how to solve the crack progression. I am also interest in the differences between your program and abaqus cohesive element.

Thanks! 


vinh phu nguyen's picture

Hi Hu, My code implements

Hi Hu,

My code implements the standard interface elements within the framework of cohesive zone models. I do not know the Abaqus implementation so I cannot describe the difference.

Happy new year,

Phu


Jianxu Shi's picture

Phu, I have a related

Phu,

I have a related question to Abaqus: can you code work on Abaqus input file: aka, input=abaqus inp file without interface elements, output=new abaqus input file with interface elements block inserted in a specified solid region.

 PS: I am interested in obtaining a copy of your program. we can talk about future collaboration. For more info about myself, see gem-consultant.com (quite dated but you can email me for updated info).

 Best,

J.Shi 


vinh phu nguyen's picture

Hi Shi, Although my code

Hi Shi,

Although my code currently does not support Abaqus input, it has been implemented in such a way that new input format can be incorporated easily. 

Ok, I am sending you that piece of code. 

Phu


vinh phu nguyen's picture

Hi Shi, Could you send me

Hi Shi,

Could you send me your email? I couldn;t find it in the website you told me.

 Phu


can your program is useful

can your program is useful in ansys for generating interface elements.Since i am facing problem while modelling cohesive zone.


Can you send

Hi Shi,

I am interesting in computational mechanics. Can you send me your code?I want to saw that how this build and how implement this code in another software.