Hello Mr. Mikola,

I have to set the primary stress state at an angle that can be explained by the fact that at this point, a deflection occurs in the tunnel (stress direction alignment) What steps are needed to implement a rotated primary stress state in the model? How can we identify possible damage zones around the tunnel structure?
Could you please also tell me, which command is for CWFS in Adonis? What possibilities exist for incorporating the CWFS approach in Adonis?

In the photo you can see, what I mean by rotation. This was an example in a programm called FLAC2D.
​​​​​​My question ist, is there a possbility in ADONIS too?

Thank you
Rebecka

Hi,

For rotated stress, there's no direct method available. However, you can project the stress onto the x and y axes and then use stress initialization to set it up. The program includes a stress initialization feature, which is detailed in Tutorial #7.

For CWFS, you can use the strain-softening constitutive model in the program. This model controls hardening and softening through predefined cohesion and friction, similar to the approach described in the FLAC manual and examples. To implement this, create a table with plastic shear strain in the first column and cohesion and friction in the second column, then specify this table in the constitutive model dialog.

-Roozbeh

Hello,

thank you so much for the quick response. I will try to continue my work with your advice and I will share my results as soon as I can.

Thank you!
-Rebecka

Hello,
I'm looking for tutoring in Adonis. I need a lot of help. I am new and have a difficault task to do. Mr. Roozbeh, do you know someone, I can do online call and can help me?

Thank you
Rebecka Abed Al Nour

Hi,

The best way I can assist you is right here, but it?s important to have a solid grasp of the basics first. Without understanding the fundamentals of numerical simulations, the process will be challenging.

As I mentioned, I?m here to help. However, you need to start by creating your model and drafting a clean script, similar to the examples shown in tutorials or shared by other users. Once you?ve done that, share your model here, and I?ll guide you further.

Here?s my advice:

1- Create the geometry of your model and generate a mesh.
2- Assign a simple elastic constitutive model to the different layers of the model?keep it straightforward to start.
3- Assign external forces or stresses and proper boundary conditions.
3- Run the model, debug it, and ensure there are no issues.
4- Gradually add complexity to your model, such as incorporating more advanced constitutive models or varying in-situ stress levels, as needed.

This step-by-step approach is how I tackle complex models myself.

Best,

Roozbeh

Hello again,

thank you again. I did the Basic modell (tutorial 1). I gave my system strain-softening property. Now I am trying to rotate it by 19?, 27?, 35?, 43? and 51? like the photo I send. If I want to rotate it, how can I know if its sxx or syy that should habe a x and y variation? You send me tutorial 7 but I dont understand how tos start...
so lets say i have
sxx= -25e6
syy=-50e6
szz=-50e6

how should I start? So what effects x variation and y variation for each one? How I can rotate it like the screenshot? For example 19?? change in sxx, syy or szz? or all? I really need an Explanation.

It would be a pleasure if you have time.

Thank you

Hi,

If you want to apply a constant stress throughout your model, follow these steps:

1. Navigate to Menu -> Initial -> Apply Insitu -> Element Stress. 
2. Select the desired stress component (e.g., sxx, syy, or szz). 
3. Specify the value and apply it to all elements. 

For cases where you want the in-situ stress to vary gradually (e.g., from top to bottom or left to right in the model), you can use x and y variations. These variations are defined using the following relation: 

modified_value = value + v_x * x + v_y * y

Here: 
- modified_value is the new stress value at a given location (x, y). 
- value is the stress at the reference point (e.g., at x = 0, y = 0). 
- v_x and v_y are the variation coefficients for the x and y directions, respectively.

The program calculates the stress at each element based on the position of the Gauss point and the specified coefficients. To use this method, estimate the initial value, v_x, and v_y to fit your requirements. 

If a single, uniform stress value is needed, variations (v_x, v_y) are unnecessary. Simply assign the constant value directly.

To apply angled stress, project the stresses onto the x and y axes using trigonometric projections. Then, assign the calculated values to sxx and syy. You can use tensor transformation equations to compute sxx and syy for the given angle.

https://eng.libretexts.org/Bookshelves/Mechanical_Engineering/Mechanics_of_Materials_(Roylance)/03%3A_General_Concepts_of_Stress_and_Strain/3.03%3A_Tensor_Transformations

Thank you so much for the detailed reply!

I will try to get a better understanding of the process!

-Rebecka