Plane strain 2d cylinder stress analysis in APDL 16.0

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Md Ahad posted this 2 weeks ago

when i create layered cylinder with different material then putting pressure on the inner line of the cylinder i get the max stress only for the first layer.Adjaent layer next to the first layer has no radial stress.I am very upset with this.Anyone can help me regarding this problem?I badly need assistance.

Thanks in advance.Here i attached the nodal solution of stress where i can see that only frst layer got pressure and felt stressed.But the other layer is blue totally

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peteroznewman posted this 2 weeks ago

It will be easier for someone to assist you if you attach a zip file with your input file to your post.

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Md Ahad posted this 2 weeks ago

Thank You very much for your response peteroznewman .I will upload my file Asap . May i get your email id???

peteroznewman posted this 2 weeks ago

Md Ahad, I am not an APDL user. If you were to create this model in Workbench, maybe I could help. I only give out my email when I think I can help.

I don't see any file attached to your reply. This site will accept .zip files. Do you have WinZip or 7zip to compress your input file?  Once you do that, you can use the Attach button to attach it to a post, or use the Browse button while you are writing a reply.

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peteroznewman posted this 1 weeks ago

I don't use APDL classic ANSYS, but I was able to open and solve your file.

One observation is that the nodes between the inner and the middle rings don't line up,
while the nodes between the middle and outer rings do line up.

Is there contact between the inner and middle ring, or is this the mistake you are looking for?

If someone else can help, that would be great.

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peteroznewman posted this 6 days ago

You must either:

1) Add bonded contact between each layer or

2) Line up the nodes at the two interfaces between the rings and merge coincident nodes.

I know how to do that in Mechanical and I don't know how to do that in ANSYS APDL.

Do you want to build your model in Mechanical?

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Md Ahad posted this 6 days ago

aren't mechanical and mechanical apdl same?

peteroznewman posted this 5 days ago

Mechanical is the program to build models and review results which is started from Workbench after you select the physics. Mechanical APDL is the name of an older user interface to build models and review results.  They all use the same solver.

I also realized there is a mismatch between the title of your discussion and the model you built. The title uses the word axisymmetric, but the geometry you drew is a plane strain 2D model. Below I used Workbench to make an axisymmetric model of a 3 layer tube with an internal pressure.

 

Attached is a ANSYS 15.0 archive that you can download and use in ANSYS 16.0. Start Workbench 16.0, then use File, Restore Archive... and pick this file.

Attached Files

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Md Ahad posted this 5 days ago

can you help me for plane strain 2d please. Another thing is that the model should be like the model i drew.And putting temperature on the inner surface 1000 deg celcius.It would be very helpful if you contact me through mail.my mail id is: mdahadalam@outlook.com  .

peteroznewman posted this 5 days ago

Your first post mentioned a pressure load. Is the temperature in addition to the pressure? 
Can you provide the complete problem specification? What is the pressure?
Is this a Steady State Thermal problem?  What is the zero strain temperature?
What is the boundary condition on the outside diameter? Temperature or Convection?
If convection, what is the film coefficient and the ambient temperature?
What are the material properties?  I need CTE, Conductivity, Young's Modulus and Poisson's Ratio.
What is the internal Radius, and the three wall thickness values?
Are you going to be using Workbench now?

Here is another video to convert the same problem into a plane strain problem. Note: I revised some values of Young's Modulus and the pressure since I made the first video above, but the archive below has the revised values in it. Please compare the axisymmetric stress with the plane strain stress and reply with what you find.

 

I have saved your email address. You can edit your post to remove it, if you don't want to share it with the rest of the world. I prefer to communicate on this website than via email.

Attached Files

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Md Ahad posted this 5 days ago

Thank you very much dear. I wanted this kind of model. I am giving you my problem. You just try to solve it and give me output result according to what i expected as a outcome.

Again thanking you . for your struggling

Md Ahad posted this 5 days ago


Attached Files

Md Ahad posted this 5 days ago

I have attached my problem. I would be very happy if you solve this problem in your solver and showing the output result,plot the graph of result of strain vs radial distance(4.7mm to 5mm portion only).All the condition including pressure and inner and outer temperature are given in the attached picture.Additional thermal conductivity are given for the each layer too.

Thank you very much for all your support.I would be very thankful if you help me learning by modeling this problem from the beginning.

Md Ahad posted this 4 days ago

hi peteroznewman.You didnt response of my problem

peteroznewman posted this 4 days ago

Dear Md Ahad,

I am here to learn new skills in ANSYS, and your problem has given me that opportunity, so thank you for participating.

I thought you were here to learn ANSYS. I gave you a Workbench 15.0 .wbpz file with instructions on how to restore that file. I suggested you investigate the two models included in that project, but you didn't mention that you looked at that project or were even able to open it.

I'm willing to show you how to obtain results from a two-layer model with all the pieces you need to build a model with the specific data in your sketch, but I'm not interested in the specific results of your eight-layer model. That is for you to create. I'm here to help you learn, not to provide results to your problem.

I participate here out of my own interest, it's not my job, it's my hobby. This is a student community, not paid technical support. Please adjust your expectations accordingly. I will respond later today (my time zone is EDT) with a model that shows how to get results from a two-layer problem. You can show your appreciation by clicking Like below the posts that are helpful.

Sincerely.

 

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Md Ahad posted this 4 days ago

Ok .Thank you for clearing the views.Yes i am also here to learn.That sketch what i gave you that is not my motive to research about.My original model is something else where all the knowledges to create that sketch will help me finished that or reach my goal.I am very grateful to you for giving me your valuable time and hard work.Ok no problem.Help me according to your comfort zone.

 

Thank You.

peteroznewman posted this 4 days ago

Glad we have an understanding.

I built a simple model in Workbench of the thermal conditions, then I linked the solution of the thermal model to use in the structural model and found I got no stress. I wondered why that was for a while, then I realized I had forgot to input a CTE, which is also missing from your sketch. I will use typical examples in my simple model (or you can provide some values) and use those in the next video that will demonstrate the one-way coupling of a thermal and structural model using Workbench.

While I was researching why I got no stress, I came across this YouTube video that shows how to do a one-way coupling using Mechaical APDL (not Workbench), but the geometry is a very simple line body. Maybe you can learn something from this if you want to learn Mechanical APDL.

 

 Here is the video that may help you learn how to create bonded contact in Mechanical APDL, which is what you needed at the beginning of this thread.

 

I am learning how to apply APDL commands inside the Workbench/Mechanical environment.

Kind regards.

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peteroznewman posted this 4 days ago

I made a video using ANSYS 15.0 to show how to take the results from a thermal model and use them in a structural model to calculate the stress due to the thermal expansion as well as applying an internal pressure. At the end I show that 2D models give very different results for out-of-plane stress depending on whether the Plane Stress or Plane Strain equations were used in the model.

Attached Files

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Md Ahad posted this 4 days ago

well thanks you for the help.You have sent me a video that you are learning mechanical apdl.On the contact pair video i learnt that how to contact two surfaces.May i use the same contact btween the layers what i first sent you the model of the mechanical apdl?

Another thing,As um new here,i dont know how this community works even.I am using this post as a medium of our conversation.So if i mark this post as solved,will you be benefitted?if so,then i would.If not then i am using this post as usual.If you have another way to communicate with me then please do share.I will share my problems on that communication medium.

 

Thanks in advance.

peteroznewman posted this 3 days ago

Yes, I hope you can apply the lesson in the bonded contact video to your Mechanical APDL model.  I found these videos while searching YouTube for examples of thermally induced stress and passed them on to you because you are a Mechanical APDL user.  I didn't actually watch the videos because I have chosen not to learn how to use the Mechanical APDL user interface. I use the Workbench/Mechanical user interface.  I created a video to demonstrate how to build your model in Workbench, but you seem committed to using Mechanical APDL like I am committed to using Workbench.

Both user interfaces create APDL code for the solver to read, and to view the results, but there is a big difference in how you interact with the interface to prepare it to write that code or plot a result. In both cases, direct APDL code entry is possible.

The Student Community consists of Discussions, which are on a specific topic, and the topics are grouped into categories. This is a public website, and Google constantly indexes the content, like it does everywhere on the Internet. I have seen some of my posts show up in Google search results.

Most discussions originate because a member has a question. Any other member can read the post and reply. Sometimes I will have a back and forth with one member on a particular problem, and another member is interested in that problem and will have a question or comment. The communication is open for all to read, so that it is a many-to-many discussion. Email is a one-to-one discussion. That is less useful since I may not know something that another member does, but they can't see the email communication and can't contribute.

If the original poster of the discussion feels they have got an answer to their question, then the discussion can be marked "Is Solved" and the topic has a green check mark. That tells other members that the original poster has what they need. Any member can still add a Post to a Solved discussion if they want to add something.  If I am looking to help someone, I might skip over Discussions that are marked as Solved. So you could mark this Discussion as "Is Solved" if you have all you need for now.  You can start a new Discussion when you have a new question.

There is also the Tutorials section of the Community where members can post information on how to do something that people might find useful. I am going to post the last video over there, so anyone who needs help solving that type of problem can see an example of it. Since these posts are not really questions, the Solved flag is not really relevant.

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Md Ahad posted this 3 days ago

Thank you very much for all your supports.But one thing you have mistaken that is um not commited to use apdl.The thing is um too bz to to work on workbench.Getting free i will obviously try to learn on workbench by your videoes.

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