I jost installed Inventor 2013 Premium (PRODUCT DESIGN SUITE) here at the company and I have noticed that there is no "Stress Analysis" button in the Environments Tab. I already checked the "manage Add-Ins" button and there is no Stress Analysis module available in the list of Add-Ins.
Am I reading this wrong or this version may not have a Finite Element Analysis module?
It is strange because in the brochure there is a stress analysis module. Also, in the Environments tab there is an "Optimization" button. What is the purpose of having optimization without having Stress Analysis?
Could this be a bug?
Thank you in advance for the help!
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Unless it's changed for 2013 release you need Inventor Pro for stress analysis and you need Product Design Suite Ultimate for Inventor Pro...
^ With your Product Design Suite Premium 2013 you have Inventor (with Routed Systems) but not Inventor Pro.
I think you are correct. It is a pitty that this version does not have FEA as well.
I hope it becomes a standard package in the future for all versions.
lol thats funny. I know the talk when Inventor came out that it was going to be all in one package thats what they sold it on. Because Pro-E you bought Mods so when inventor came out thats what they told everyone that Inventor will be an all in one package no mods..
Oh and one package not what they have now like 5
I myself am a fan of simple software. Have it all in one place, and make it efficient, that's my style.
I have just recently started working in Inventor. It was amazing to see how many different programs are available to install from this package alone (Inventor, 3DS Max Design, etc, etc...). Honestly, I do not care about any of the other software packages... but not having FEA as a standard Add-In? Nowadays, FEA has become so useful that selling a mechanical CAD program that does not include it is like selling a car without the engine.
Forgive me if this seems incoherent, because I am on some medication, but I found that since I am on subscription, I have autodesk 360 cloud services available. When you read the services listed, the Inventor Optimization is listed as a feature that is accessible from the Autodesk Product Design Suite Premium 2013. Note: This is not an Autodesk Inventor Pro install, only normal Autodesk Inventor.
So, today I went to the cloud service and activated my optimization function by downloading a file that is supposedly for Inventor 2012. Sure enough, I can now go to the Environments tab and click on Optimization, apply the loads, pins, parameters, etc and once everything is entered, the "optimize" button appears. When I press the button it sends it to the cloud and after a few minutes the cloud returns the result.
Now, I'm stuck trying to figure out exactly what I am seeing. I simulated a simple flange on a pressure vessel that will have 20psi inside. I expected to see parameters of flange displacement and such as pressure is applied, but it only wants to optimize for flange weight by changing the flange thickness. My result show max 15ul and min 2.95 ul. What is that? It's saying it is a "safety factor". Does this mean safety before flexing? Before catastrophic failure? What?
When I watch the movie of my 3/4" thick 20" diameter steel flange in the simulation, it appears to be flexing 3 or 4 inches outward as the pressure is applied. Is it just exaggerating the motions? pictures attached.
Is the optimization worth anything without having access to all the FEA elements?
Perhaps it is obvious by my post, but I am not a mechanical engineer. I just like to play with this stuff.
To avoid any confusion from my previous post, the pressure vessel is to the left of the flange providing 20psi force, The chamber to the right is another chamber that serves as the pinning flange, so flexture toward the right is expected in the result. I'm simply confused by the nomenclature of "safety factor" in "ul" units.
What you are describing is the as-designed behavior of Optimization for Inventor.
1) Specify the load and boundary conditions
2) Nominate model parameters to investigate how varying these will affect the stress induced (i.e. Safety Factor) with the same loading conditions
3) In the settings, the target Safety Factor can be specified, along with coarse or refined type (this is a convergence setting equivalent to changing maximum number of h-refinements to 3 in Stress Analysis)
4) The configurations will be solved in the cloud, and the 'optimum' configuration is returned with satisfies both the minimum SF requirement, while choosing the best size to minize the mass of the structure (hence saving material, cost, etc.)
The safety factor is just a different way of expressing the Von Mises (Equivalent) stress by dividing the material's yield strength, by the stress value. For example, if the yield strength is 250 MPa, and the maximum VM stress is 125 MPa, the corresponding SF would be 250/125 = 2.
If you are dealing with brittle materials, the Ultimate Tensile strength should be chosen as the SF criteria (in the Assign Materials dialog) since brittle materials have basically the same Yield and Fracture stress and safety factor is a bit more involved since we will take the principal stresses into accout instead of just maximum Von Mises as we do for yield strength.
The simulation can be exported from OfI to Stress Analysis for futher investigation where the loads and constraints will remain in-tact as well as the Simulation setup which is equivalent to the parametric dimension design objective simulation type that has the appropriate mass and SF design constraints defined.
R2013 also has the addition of the new DKT shell element type. If you are conducting a pressure vessel simulation, shell elements would be particularly suited for those 'thin body' types of geometry.
Hope this helps! As always, please let us know if you have any additional questions, comments of suggestions.
Best regards, -Hugh
[Edit: fixed type of 'teh']
"Is the optimization worth anything without having access to all the FEA elements?"
I have a preference for having access to all FEA elements first, check the results for the simulations, and only then do I procede to optimization (if required).
"I'm simply confused by the nomenclature of "safety factor" in "ul" units."
Well, in Inventor "ul" means "uniteless", and this is being shown because the safety factor has no units.
You can google it to find out more about what "safety factor" is.
Just to give you a quick answer, lets just say that in engineering there are a lot of unknows and things that are hard for the engineer to predict.
So, if we are designing a component to handle a certain load, we design it to be twice as strong, and some times more, to account for all the umpredictable factors.
So, the higher the safety factor is, the better.
Thank you all for your responses. It is mostly clear now but I have a couple more questions.
You say I can export my results to stress analysis for further investigation? Is this true in my case where I only have Autodesk Inventor with cloud services, but not Autodesk Inventor Pro? I can hit the export button, but I seem to have no other button to open the actual stress environment. I have also not found the DKT shell element you speak of. Is this also only in Pro?
So here I had the 1" thick steel 20" flange and I "optimized" thickness for 20psi load. I would have expected the program to say "hey, this is crazy, you can reduce the thickness to 1/4" and achieve a 3X safety margin. Instead, it only changes the width by a small amount and comes back and tells me that the best result is 0.85" thick and it has a 12X safety margin. What did I setup wrong? Is this simply not powerful enough unless I invest in Inventor Pro?
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