Varying traction load

[SothunN]

Hello everyone, I have a 2-dimensional geometry and I want to apply varying traction loads on the inside surfaces since I use rectangular coordinates. And I know that I have to form the analytical field but I do not know what kind of expression can help me to get the varying traction loads I want. So is there anyone who can tell me about that? And I have attached the sample below. Thanks!!!

 

[FEA way]

How are these loads supposed to be oriented with respect to the inner edges and how should they vary along the edges ? Maybe share a simple sketch with arrows approximately representing loads drawn on that screenshot from your first post.

 

[SothunN]

By using the ratio of change in the X and Y axis (slope formula). I have calculated and sketched them out but I do not know how to set the expression in Abaqus.

 

[FEA way]

So please share that sketch if you can. It will help.

The following documentation chapter may help: "Abaqus/CAE —> Using toolsets —> The Analytical Field toolset —> Using analytical expression fields —> Building valid expressions".

 

[SothunN]

Here is the sketch that I got from my analysis.

 

[FEA way]

If your formula used to calculate the loads can be converted to an equation based on X,Y,Z coordinates (not necessarily of the global coordinate system) then analytical expression field should work. But it's often the case that such conversion can't be done (for example because of some additional parameters) or is too difficult and then there are other options - mapped fields (values specified for individual coordinates - maybe that would work in your case since you already evaluated this formula and obtained load values at different points) and DLOAD subroutine.

 

[SothunN]

I think there is no option for traction force to use in mapped fields, but if you know please let me know. And since I have used the ratio of change in the X (X1, X2) and Y (Y1, Y2) axis to calculate the traction force on the surfaces so is there any way can I form this type of expression (for example slope formula slope=y2-y1/x2-x1)?

 

[FEA way]

Mapped fields can be used only with pressure loads. Since your formula contains additional parameters, it may not be feasible to define it in a simple editor for expression fields. So you could either evaluate it and apply it to discrete points (scripting could also help with that) or code it in a user subroutine.

 

[SothunN]

If I do not know how to do scripting or coding, is there any way or what is the best way to get like what I want?