Linear Static Analysis not running??
i have been trying to run linear static analysis on this structure but despite several efforts, the simulation is not running and ends up in error. can someone have a look over it and resolve the issue. the constraints and the forces are well applied in the model. thank you for your support
Answers
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You have a shell element with a solid property
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As an additional suggestuon to Jason's post, also use the Model Checker to make surw most of the common errors are checked before running.Jason Craanen_20442 said:You have a shell element with a solid property
https://community.altair.com/community?id=community_question&sys_id=f076043a1b2bd0908017dc61ec4bcbed
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Jason Craanen_20442 said:
You have a shell element with a solid property
Thank you for your message and feedback. I want to run it as a solid element body. it will be grateful if you could fix everything and send me the file that i can execute and run it. i am very new to Hypermesh so have almost no knowledge on this software
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Adriano A. Koga_21884 said:
As an additional suggestuon to Jason's post, also use the Model Checker to make surw most of the common errors are checked before running.
https://community.altair.com/community?id=community_question&sys_id=f076043a1b2bd0908017dc61ec4bcbed
Thank you sir for your feedback. very helpful tool
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Muhammad Shadab Khan said:
Thank you for your message and feedback. I want to run it as a solid element body. it will be grateful if you could fix everything and send me the file that i can execute and run it. i am very new to Hypermesh so have almost no knowledge on this software
I would ask you to take a look at the resources on tet meshing (including taking some basic training)
Youtube
https://www.youtube.com/watch?v=cUf3wbA_dLwTraining
Help Documentation
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Jason Craanen_20442 said:
I would ask you to take a look at the resources on tet meshing (including taking some basic training)
Youtube
https://www.youtube.com/watch?v=cUf3wbA_dLwTraining
Help Documentation
dear sir, i followed the tutorials you sent and i have tried to re-run the simulation but i am now getting a different type of error. i attach you the error screenshot for your reference. thank you for your support.
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Muhammad Shadab Khan said:
dear sir, i followed the tutorials you sent and i have tried to re-run the simulation but i am now getting a different type of error. i attach you the error screenshot for your reference. thank you for your support.
Your LOADADD card is referencing your SPC
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Dear Sir, In the Hypermesh Property section, what is the Membrane Thickness? whenever i increase the value of T in this part, i notice that the maximum stress value gets reduced while increasing the thickness accordingly. What is the criteria for selecting the value of membrane thickness? How should we determine what thickness is needed for our analysis? attached the screenshot.
thank you,
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Muhammad Shadab Khan said:
Dear Sir, In the Hypermesh Property section, what is the Membrane Thickness? whenever i increase the value of T in this part, i notice that the maximum stress value gets reduced while increasing the thickness accordingly. What is the criteria for selecting the value of membrane thickness? How should we determine what thickness is needed for our analysis? attached the screenshot.
thank you,
It is the thickness of your shell element. It should be representative of you original solid part or cad.
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Jason Craanen_20442 said:
It is the thickness of your shell element. It should be representative of you original solid part or cad.
Alright sir. So the thickness of my CAD part is 1 mm so in this case, i should use 1 in this field
?Also when i run this simulation in another software Fusion 360, i get different value for the Von Mises Stress there ( lower value) compared to the Von Mises result in the Hypermesh. the displacement value is more or less the same in both software but there is a big difference in the Von Mises value, what can be the reason behind this anomaly
thank you
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Muhammad Shadab Khan said:
Alright sir. So the thickness of my CAD part is 1 mm so in this case, i should use 1 in this field
?Also when i run this simulation in another software Fusion 360, i get different value for the Von Mises Stress there ( lower value) compared to the Von Mises result in the Hypermesh. the displacement value is more or less the same in both software but there is a big difference in the Von Mises value, what can be the reason behind this anomaly
thank you
T =1.0 in your model. >> 1mm thickness assigned to your shell property.
When comparing results from different softwares it is always important to understand what are you considering in both cases, if this is exactly the same modeling in both, or not.
For example, many CAD tools use simpler 3D tetra elements for building the model, which is ok for many cases, specially when the part is a bulky solid part.
But for thin parts like yours, shell models usually capture stress values very well, as long as they're refined enough (the same for the solid tetras).
So if you did it right on both your results should match quite well. But, if in the solid model, if the mesh is not refined enough, you might get some under representation of your stress values.
Even in the shell model, if your element is too big, then stresses will be averaging a large area. But thickness-wise, this should capture better the stresses, with less computational cost.
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Adriano A. Koga_21884 said:
T =1.0 in your model. >> 1mm thickness assigned to your shell property.
When comparing results from different softwares it is always important to understand what are you considering in both cases, if this is exactly the same modeling in both, or not.
For example, many CAD tools use simpler 3D tetra elements for building the model, which is ok for many cases, specially when the part is a bulky solid part.
But for thin parts like yours, shell models usually capture stress values very well, as long as they're refined enough (the same for the solid tetras).
So if you did it right on both your results should match quite well. But, if in the solid model, if the mesh is not refined enough, you might get some under representation of your stress values.
Even in the shell model, if your element is too big, then stresses will be averaging a large area. But thickness-wise, this should capture better the stresses, with less computational cost.
Dear Sir,
Thank you for your update. How can we define Solid Body in Hypermesh. When I try to assign PSOLID, i get error and it does not run the simulation. The Simulation i did in Fusion 360 was as a Solid Body element but in HyperMesh it was PSHELL. please have a look over the error.
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Adriano A. Koga_21884 said:
T =1.0 in your model. >> 1mm thickness assigned to your shell property.
When comparing results from different softwares it is always important to understand what are you considering in both cases, if this is exactly the same modeling in both, or not.
For example, many CAD tools use simpler 3D tetra elements for building the model, which is ok for many cases, specially when the part is a bulky solid part.
But for thin parts like yours, shell models usually capture stress values very well, as long as they're refined enough (the same for the solid tetras).
So if you did it right on both your results should match quite well. But, if in the solid model, if the mesh is not refined enough, you might get some under representation of your stress values.
Even in the shell model, if your element is too big, then stresses will be averaging a large area. But thickness-wise, this should capture better the stresses, with less computational cost.
here is the attached file as well.
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Muhammad Shadab Khan said:
here is the attached file as well.
Hello,
This comes back to the original issue. You need to create solid elements. I provided some resources to look into.
I also recommend you start taking some basic training. These are necessary things to know about basic FEA.
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Jason Craanen_20442 said:
Hello,
This comes back to the original issue. You need to create solid elements. I provided some resources to look into.
I also recommend you start taking some basic training. These are necessary things to know about basic FEA.
Sir; I already checked the tutorials but could not find any tutorial that could classify the PSHELL and PSOLID. what does it mean by PSOLID or PSHELL in the simulation and how it affects the results? thank you
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Muhammad Shadab Khan said:
Sir; I already checked the tutorials but could not find any tutorial that could classify the PSHELL and PSOLID. what does it mean by PSOLID or PSHELL in the simulation and how it affects the results? thank you
PSHELL >> property for shell elements >> assign this property to a shell model, defining the equivalent thickness 'T'
PSOLID >> property for solid elements >> assign this property to a solid model (tetra or hexa elements)
I suggest you to go through this ebook with practical aspects of FEA.
It will help you on these questions.
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Adriano A. Koga_21884 said:
PSHELL >> property for shell elements >> assign this property to a shell model, defining the equivalent thickness 'T'
PSOLID >> property for solid elements >> assign this property to a solid model (tetra or hexa elements)
I suggest you to go through this ebook with practical aspects of FEA.
It will help you on these questions.
Dear Sir; Thank you for your feedback. Here the Equivalent thickness T refers to Thickness of the CAD file. For example in my case the CAD file is a cuboid which has a thickness of 2 mm so in this case the Equivalent Thickness T to be inserted in the PSHELL would be T= 2 ? or there is something else?
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Muhammad Shadab Khan said:
Dear Sir; Thank you for your feedback. Here the Equivalent thickness T refers to Thickness of the CAD file. For example in my case the CAD file is a cuboid which has a thickness of 2 mm so in this case the Equivalent Thickness T to be inserted in the PSHELL would be T= 2 ? or there is something else?
PSHELL Thickness is the shell Thickness, from the CAD.
Shells are used in certain models to represent thin structures. A cuboid may not be ideal for shell depending on their dimensions.
Take a look at the ebook I've sugested if any questions still remain.
This is a capture from there.
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Adriano A. Koga_21884 said:
PSHELL Thickness is the shell Thickness, from the CAD.
Shells are used in certain models to represent thin structures. A cuboid may not be ideal for shell depending on their dimensions.
Take a look at the ebook I've sugested if any questions still remain.
This is a capture from there.
Thank you for your prompt response sir. The thickness of plates in my case is 1 mm as you can see the attached screenshots, the dimensions of cuboid are 750*450*450 mm but the thickness of walls is 1 mm so in this case when we define PSHELL we consider T= 1 mm (thickness of cuboid walls) or T =450 (thickness of cuboid) . i have three different cuboids of 0.5 mm, 1 mm and 2 mm wall thickness so i have to analyse all the three.
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Muhammad Shadab Khan said:
Thank you for your prompt response sir. The thickness of plates in my case is 1 mm as you can see the attached screenshots, the dimensions of cuboid are 750*450*450 mm but the thickness of walls is 1 mm so in this case when we define PSHELL we consider T= 1 mm (thickness of cuboid walls) or T =450 (thickness of cuboid) . i have three different cuboids of 0.5 mm, 1 mm and 2 mm wall thickness so i have to analyse all the three.
If you want it a solid cube, model as a solid with solid elements.
If you want it as an enclosure with defined wall thickness, use shell elements.
Please go review the training resources we have provided. These things that you are asking are the basic building blocks of FEA you should already have a firm grasp on.
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Muhammad Shadab Khan said:
Thank you for your prompt response sir. The thickness of plates in my case is 1 mm as you can see the attached screenshots, the dimensions of cuboid are 750*450*450 mm but the thickness of walls is 1 mm so in this case when we define PSHELL we consider T= 1 mm (thickness of cuboid walls) or T =450 (thickness of cuboid) . i have three different cuboids of 0.5 mm, 1 mm and 2 mm wall thickness so i have to analyse all the three.
in shell models, you create a mesh at the midsurface and assign T for wall thickness. But you could go through some basic courses in order to get more familiar to these concepts, ok?
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