Thermal Presure Simulation - Help

[danijel.radenkovic]

Hello to all,

I would like to simulate an welded assembly in Autodesk software, so I have searched and found that Simulation Mechanical is maybe the software which could help me.

This is just an example created in Inventor 2017. Could someone tell me is it possible to test this welded assembly on thermal pressure caused by steam?

Any advice, help, tutorial is very appreciated.

Danijel

[marwan_azzam · Accepted solution]

Hello Danijel,

You can certainly model this 3-part assembly in Autodesk Simulation Mechanical.

1. I would use a symmetry model (1/4 or less).  This will make it easier to constrain the model and cause it to run faster.
2. The source of the pressure (thermal or otherwise is not important).  You will apply a pressure load to the surfaces of interest.
3. As far as the welded connection there is more than one way to deal with it.  The first distinction is whether you want to model the weld material or not.

With Weld material:

1. Weld material has to be incorporated in the CAD model as its own part(s)
2. In Simulation Mechanical the weld parts would have bonded contact with the parts they are joining.  The joined parts would have free or surface contact

Without Weld material:

Set the contact between the welded parts to either welded or bonded.

[danijel.radenkovic]

---

@marwan_azzam wrote:

Hello Danijel,

You can certainly model this 3-part assembly in Autodesk Simulation Mechanical.

1. I would use a symmetry model (1/4 or less).  This will make it easier to constrain the model and cause it to run faster.
2. The source of the pressure (thermal or otherwise is not important).  You will apply a pressure load to the surfaces of interest.
3. As far as the welded connection there is more than one way to deal with it.  The first distinction is whether you want to model the weld material or not.

With Weld material:

1. Weld material has to be incorporated in the CAD model as its own part(s)
2. In Simulation Mechanical the weld parts would have bonded contact with the parts they are joining.  The joined parts would have free or surface contact

Without Weld material:

Set the contact between the welded parts to either welded or bonded.

---

Hello sir,

Thank you for the quick reply!

I will follow your instructions and I have few more questions according to steps that you provided:

1. I will use 1/4 of model for calculation to speed up calculations. Do I need to add some constraints on the splitting faces?

2. I will apply pressure of load on the all inner surfaces (on 1/4 part). How do you mean the source of pressure in not important? My input parameters are p=18bar and T=200°C. What about behavior of model's material with this inputs?

3.Firstly, I will try without weld by setting the surface contact between parts (cause this is the first time that I am working with this type of analysis) but I will do analysis with welds later.

Thank you very much again!

Danijel

[marwan_azzam · Accepted solution]

Hello Danijel,


You are welcome.


1- Do I need to add some constraints on the splitting faces?


You most certainly do.  You need to apply symmetry boundary conditions on the surface(s) that fall on the planes of symmetry.  Please see this and this section of the documentation.


2a- How do you mean the source of pressure in not important?


A pressure load is applied to a surface as force per unit area.  It does not matter what causes such pressure since it will be applied to a surface just the same.


2b- What about behavior of model's material with this inputs?

If you think that the material properties will be different (to an extent to have an effect on results) at 200C compared to room temperature then you need to enter the material properties at that temperature.  200C is probably not that high.


3- Firstly, I will try without weld by setting the surface contact between parts


Please refer to this section of the documentation for an explanation of what the different contact types do.  Setting everything to surface contact will probably result in an unstable model.

[danijel.radenkovic]

---

@marwan_azzam wrote:

Hello Danijel,


You are welcome.


1- Do I need to add some constraints on the splitting faces?


You most certainly do.  You need to apply symmetry boundary conditions on the surface(s) that fall on the planes of symmetry.  Please see this and this section of the documentation.


2a- How do you mean the source of pressure in not important?


A pressure load is applied to a surface as force per unit area.  It does not matter what causes such pressure since it will be applied to a surface just the same.


2b- What about behavior of model's material with this inputs?

If you think that the material properties will be different (to an extent to have an effect on results) at 200C compared to room temperature then you need to enter the material properties at that temperature.  200C is probably not that high.


3- Firstly, I will try without weld by setting the surface contact between parts


Please refer to this section of the documentation for an explanation of what the different contact types do.  Setting everything to surface contact will probably result in an unstable model.

---

Hello sir,

I have followed your instructions and I have recorded what I did. I would appreciate if someone take a look and give me suggestions if I missed something or I did something wrong. Also, I would like to do animation about model deforming with pressure from 0bar to 18bar.

https://youtu.be/YKPTLIBKu0c

[AstroJohnPE · Accepted solution]

Hi Danijel

I think that no one can know if you missed something or did something wrong because we are not familiar enough with what you are doing to make those decisions. We do not know the details of the design, purpose, and so forth.

Since you know what you are designing, you should be able to tell from all of the results (displacement, stress, reaction forces, and so on) whether the analysis is setup properly. Do you think something is wrong? Keep in mind that the mesh is way too coarse to get accurate results, but the results that you do have should be enough to tell you if the analysis is setup properly.

To create an animation, click the "Results Contours > Captures > Animate" to save an animation as a file, or the "Start" button to play an animation on the screen.

[danijel.radenkovic]

---

@AstroJohnPE wrote:

Hi Danijel

I think that no one can know if you missed something or did something wrong because we are not familiar enough with what you are doing to make those decisions. We do not know the details of the design, purpose, and so forth.

Since you know what you are designing, you should be able to tell from all of the results (displacement, stress, reaction forces, and so on) whether the analysis is setup properly. Do you think something is wrong? Keep in mind that the mesh is way too coarse to get accurate results, but the results that you do have should be enough to tell you if the analysis is setup properly.

To create an animation, click the "Results Contours > Captures > Animate" to save an animation as a file, or the "Start" button to play an animation on the screen.

---

Hello sir,

Thank you for the great explanation about analysis results. It is a great privilege to be part of this Autodesk Community and to learn from the people with the experience like you. I would keep in mind everything that you and Mr. @marwan_azzam wrote.

You have asked me: "Do you think something is wrong?"; From the beginning, I have excluded welds from the design. I was followed by thinking that if I would be successful with the simple analysis, I would go with more complex after. So, now I am going to make analysis with more inputs and I will post results after. If I have some doubt, I will ask for the help on the forum.

Thank you very much again!

Danijel