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FEA solidworks
- Thread starter 1993terry
- Start date
- Replies 8
- Views 1,909
That is a very complicated question.
Short answer: No, looking at your picture it probably isn't good enough
Medium answer: FEA is very hard to do right for stress. In a situation like yours where the peak stress is at the point of loading, it becomes even more difficult. You need to take a hard look at how your mesh behaves around the point of loading. Even then, I wouldn't rely on FEA entirely.
Short answer: No, looking at your picture it probably isn't good enough
Medium answer: FEA is very hard to do right for stress. In a situation like yours where the peak stress is at the point of loading, it becomes even more difficult. You need to take a hard look at how your mesh behaves around the point of loading. Even then, I wouldn't rely on FEA entirely.
triumph406
Diamond
- Joined
- Sep 14, 2008
- Location
- ca
In practical terms if your boundary conditions are realistic the part is going to fail.
By asking the question I assume your new to stress analysis, and new to FEA.
I do a lot of stress analysis, and for some customers (NASA for instance) if you do an FEA analysis, they quite often want a hand analysis to validate the FEA results. If you can't do a hand analysis, then you shouldn't be doing FEA.
triumph406
Diamond
- Joined
- Sep 14, 2008
- Location
- ca
Depending on what the part is for you need to assume a factor (or margin) of safety.
So for instance if the factor of safety on yield is 3, and the yield (from your picture) is 6.204^08, then the max stress should be 6.204^08/3 = 2.068^08 for a factor of safety of 3.
For the parts we do for NASA, there's been the occasion where's there's been some concern as to the either the analysis, maybe some f'up in manufacturing, or some question as to the material, it's heat treatment and resulting properties. In those cases we would load the part to 2x (or some multiple provided by the customer) the expected load. If it passes the load testing without yielding the parts good to go. Ussually we have a NASA rep witnessing the test.
If you aren't sure how to do the FEA or a hand analysis, the best method of validating the design is to load test. If the part is supposed to withstand a tension load of (for instance) 1000kg's, then for a factor of safety you would have to load 3000kg's without yielding.
If it's a large part, you can scale down the size of the part, and scale the loads appropriately to make it manageable as a start
So for instance if the factor of safety on yield is 3, and the yield (from your picture) is 6.204^08, then the max stress should be 6.204^08/3 = 2.068^08 for a factor of safety of 3.
For the parts we do for NASA, there's been the occasion where's there's been some concern as to the either the analysis, maybe some f'up in manufacturing, or some question as to the material, it's heat treatment and resulting properties. In those cases we would load the part to 2x (or some multiple provided by the customer) the expected load. If it passes the load testing without yielding the parts good to go. Ussually we have a NASA rep witnessing the test.
If you aren't sure how to do the FEA or a hand analysis, the best method of validating the design is to load test. If the part is supposed to withstand a tension load of (for instance) 1000kg's, then for a factor of safety you would have to load 3000kg's without yielding.
If it's a large part, you can scale down the size of the part, and scale the loads appropriately to make it manageable as a start
Cole2534
Diamond
- Joined
- Sep 10, 2010
- Location
- Oklahoma City, OK
Possibly the most accurate nuance of FEA I've ever seen.
I can still remember my statics prof- "it's great for pretty pictures, beyond that you REALLY need to know what you're doing. "
Totally agree with all this did some simple stuff as part of a collage course and have a general understanding but having been on the SW simulation premium 2 day course. I would say 75% went over my head.
Cole2534
Diamond
- Joined
- Sep 10, 2010
- Location
- Oklahoma City, OK
My only experience with FEA was in college, we modeled a series of crane hooks in Ansys and applied a load to see how the different designs reacted.
I teach sophomore Strength of Materials at the local college as an adjunct. What I tell my students is that FEA is simultaneously one of the most useful and one of the most dangerous tools for an engineer. Done properly, it lets us analyze complicated structures rapidly and with good accuracy. Done poorly, it will spit out a completely wrong, but very pretty, picture. It's up to you as the stress analyst to know which is which.
I took a lot of FEA and numerical methods classes in undergrad and grad school, did my masters thesis in finite element modelling, and I've still only scratched the surface. I can't tell you the number of times I have been asked to look over another engineer's shoulder at their analysis and they had a pretty model that was going to give them completely incorrect results.
I took a lot of FEA and numerical methods classes in undergrad and grad school, did my masters thesis in finite element modelling, and I've still only scratched the surface. I can't tell you the number of times I have been asked to look over another engineer's shoulder at their analysis and they had a pretty model that was going to give them completely incorrect results.
I would agree with what has been expressed already, basically that FEA in a computer modeling program can provide a lot of information, but if you don't have the technical training and experiential background to evaluate the result, it is a short path to engineering design errors. The consequences of those errors have to be evaluated in the context of the intended functionality.
FEA as provided by (for instance) Solidworks or Fusion 360 can be used as an evaluation tool in a relative sense to get some idea of order of magnitude of potential risk for everyday design work. I would never rely on that tool as the "complete answer" to how a part will function in its stressed regime, and especially not where safety-critical parts are being designed.
FEA as provided by (for instance) Solidworks or Fusion 360 can be used as an evaluation tool in a relative sense to get some idea of order of magnitude of potential risk for everyday design work. I would never rely on that tool as the "complete answer" to how a part will function in its stressed regime, and especially not where safety-critical parts are being designed.
