UEL user subroutine - 2

[94710]

Hello to everybody. This is my first discussion on this forum. First I want say: "sorry for my bad english"

I want run an abaqus job analysis using 27 similar but different general user elements. I know I can refer to these user elements in elementDefinitions and other blockOptions in InputFile by the elementTypeKey (for example U100, U200, etc).I know I can define my general user element in a UEL user subroutine in a fortran source file.
Here is what I don't know: how can I associate my elementType Uxxxx used in inputFile to the corresponding UEL user subrotine that define it? Can I write all my UEL user subroutines in a single fortran source file or in more fortran source file.

Please, answer me. It would be very useful for my work. Any suggestion could be helpful.

 

[sendy]

Hi 94710,

*** ... 27 similar but different general user elements.***

I'm just wondering how can you have 27 types of your own element with different types of degree of freedoms for each ??

Anyway, there is JTYPE parameter available in UEL element which can be used to differ one type of UEL to others.

I'm sorry that I misunderstand your question.

regards.

 

[94710]

Thank you so much for your answer. I didn't see this simple particular in Abaqus documentation.

All elements in my model have the same degrees of freedom but because I need 27 different general user element types because I have 27 different element types (they have trial functions just a little different).

Now: in my fortran source file that I'll link to my abaqus job I must write a single UEL subroutine in which with a flow-control structure I say what are definitions for all my general user element types? (i.e. if (jtype.eq.1) then... else if (jtype.eq.2) then ...)

Thank you so much for your helpfulness

 

[sendy]

Hi 94710,

Based on the above description, I’m sorry that I, again, can’t see the need of specifying more than one master user defined element.
In my opinion, when all elements have the same degree of freedoms we just need to specify one type of user elements in input file (.inp) while others can be generated in the same way as generating elements provided in library of Abaqus. Here is the example I am talking.

***ELEM. & MATER. DEFINITION***
*USER ELEMENT, NODES=4, TYPE=U201,PROPERTIES=10,
COORDINATES=2,VARIABLES=68,UNSYMM
1,2,6
*ELEMENT,TYPE=U201
101, 101,102,202,201

In the UEL subroutine file (.for), we need to do the procedural finite element programming for single element, i.e. doing the treatment for initial condition (not necessary since users can also do it in sdvini subroutine), defining the integration points (local coordinate definition), the material and body force contributions to stiffness matrix, and the loading condition.

Then, Abaqus will call the UEL subroutine for each element which is classified as user element (i.e U201).
When users want to vary for example the state variable condition of some user elements users might utilize JELEM option.

Therefore, I don’t see the need of using so many user defined elements.

Hope this help.

Note: I might misunderstand your problem or having less experience, so I will also wait for others response.

 

[94710]

Thank you so much for your helpfulness.

I think I need different element types, because even if I have the same dofs I have different shape functions. I have written the stiffness matrix for all my element types with the software Maple.I might be in error but I think so I said. Perhaps I need to study more on this subject to be sure of what I need.

By the way If I really need different eleemnt types in my model or in a future problem, in my fortran source file that I'll link to my abaqus job I must write a single UEL subroutine in which with a flow-control structure I say what are definitions for all my general user element types? (i.e. if (jtype.eq.1) then... else if (jtype.eq.2) then ...)
or how should I do?

 

[sendy]

Hi 94710,

***By the way If I really need different eleemnt types in my model or in a future problem, in my fortran source file that I'll link to my abaqus job I must write a single UEL subroutine in which with a flow-control structure I say what are definitions for all my general user element types? (i.e. if (jtype.eq.1) then... else if (jtype.eq.2) then ...)****

In my opinion, yes, the above, sort of, flow control structure could be used; but i don't have experience of using it for different UEL type. I ever had that kind of thinking (using more than 1 UEL type), but then I finally can manage by using only one type UEL.

Hope to see other experiences in this problem.

Sorry for not helping too much.

 

[94710]

If you want know more about this discussion you can join abaqus yahoogroups and visit

http://tech.groups.yahoo.com/group/ABAQUS/message/15761

I don't know if this is an inappropriate post because I mention another forum.I think it can be useful for anybody.If I'm in error, I'm sorry.