Hello Hamid,

as I understand from you description of the model, you want the stresses through the thicknes. It means you want to have S11,S22,S33 value for all elements in a collumn that you are interested from up till down. Then you should decide which exactly collumn of elements you want to use to extract the data.

I would recommend you to create the set of elements collumn before the simulation, and after the simulation you can extract the data from the elements set and arrange them by coordinates (from up till down).

Sincrely

Pavlo Pavliuchenko

Also, you can create a path by connecting the nodes belonging to deformed cross-section and then produce X-Y plots for desired components of stress tensor.

See http://wufengyun.com/v6.14/books/usi/default.htm

48. Viewing results along a path

Hello Pavlo and Victor, thanks for your replies. I actually want to visualise the entire stress distribution in the component, let's say in the theta direction where theta varies throughout the component. Let theta be the forming direction. Please see the image attached here.

How can I get such a distribution?

Hello Hamid,

I think I do not understand you completely.

You are writing: "I actually want to visualise the entire stress distribution in the component, let's say in the theta direction where theta varies throughout the component."

Do you want to have the stresses along some specific line?

Do your S11 and S22 change the direction regarding the angle of this line? (Look Fog. 1)

If yes, then you shoud use the elements along the specific line coosing them by coordinates (see Fig. 2). And then you shoud racalculate S11 and S22 regarding the angle of you line.

Hello Pavlo,

No, no specific line. Take the same concept but extend it throughout the whole component. So therefore the axis you have drawn in your diagram should vary at every point in the component.

I essentially want stresses in the thickness direction, and perpendicular to the thickness direction. Now these directions vary along the component, since it is twisted in an S shape.

Hello Hamid,

I am not very good in 2D modeling in Abaqus and really cannot understand the problem. As I understend, the S11 and S22 are calculating regarding each element starting coordinate. It means, S11 will have the same value,

independently from rotation of the element ragarding global coordinate sysem.

So, actualy, the S11 and S22 stresses that are depicted on the picture that you have provided are those tat you need.

Hello,

Please are the Sigma_theta on the diagram I provided in my first reply. This is the stress I need. could you let me know what you do not understand about this?

Please can you tell me how to get this Sigma_theta stress, throughout the component?

This is not this is S11 and S22.

Thanks

Hello Hamid,

I believe I'm ready to give an answer to your question.

But firstly, I want to clarify again . Do you want to get a field output with stress distribution at a certain angle (θ) throughout the part? If so, then it is in principle not very difficult.

First of all, you need to apply the equation to calculate the stress at a specific angle θ. You can find it here: https://en.wikipedia.org/wiki/Mohr%27s_circle

I attached a picture with an equation for plane stresses.

You need to use equation for σn. σx here is S11, σy is S22, 𝜏xy is S12. Here you should assume that at S11(X) you have 0 degree, and at S22 (Y) there is 90 degree. See the attached picture.

Then in Abaqus, when working with *.odb-file, you should create a new Field Output:

Tools > Create Field Output > From Fields

Here you must select the step and frame from which you want to extract S11,S22,S12. Then you should apply the above equation using the required angle. Give this frame name like "Stress_angle_(theta)".

Then create one more field output using the same steps and frame as in previouse case. But here in Expression use just spatial displacement variable U (e.g. s1f319_U). Call this Field Output as "Deformation".

After that go to Results > Field output. Choose Frame "Session frame". Then go to tab "Deformed variable" and click on "Deformation" and then click Apply.

After that you can use "Plot contours of deformed shape".

Basically it is not very difficult, but you will need some time to figured it out.

Sincerely,

Pavlo

Hello, thank you for your detailed answer. However you have assumed the same angle throuugh the part which is not what I am looking for. As you can see the part isn’t in an S shape, meaning the angle Theta varies along the path length.

The angle theta is not constant as you have assumed.

Based on your responses, I believe it is clear that Abaqus can’t do what I want.

I want the stresses normal to the surface and tangental to the surface at every single point in the component (since it is an S shape theta varies throughout). This means that I need a coordinated axis which varies throughout the part.