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Hi, I am new.
Hi, I am new to Finite element analysis, and I have issues understanding the manual.
So to give you a little bit of background, I am getting into mechanical engineering as a hobby, not as a professional.
The objective is to design fictional vehicles for vehicle simulations, to ensure they perform as realsistically as the simulation will allow.
I decided to self-educate myself with resources I could find on the internet when it comes to simulating mechanical forces like stresses / strains, weights when I came across the term 'finite element analysis' among other aspects, which is where I came accross CAD simulation.
I eventually came across an engineering forum https://eng-tips.com/ where I found out about mecway.
So I decided to download it and try it out, given it has a forum and good support and a forum where I can ask questions about issues that I come across.
So after downloading the software, in order to understand how to use mecway I decided to read the manual and needless to say, I am getting a little overwhelmed with terms that I am not exactly familiar with by chapter 6.
I guess I need help.
Thank you for reading.
So to give you a little bit of background, I am getting into mechanical engineering as a hobby, not as a professional.
The objective is to design fictional vehicles for vehicle simulations, to ensure they perform as realsistically as the simulation will allow.
I decided to self-educate myself with resources I could find on the internet when it comes to simulating mechanical forces like stresses / strains, weights when I came across the term 'finite element analysis' among other aspects, which is where I came accross CAD simulation.
I eventually came across an engineering forum https://eng-tips.com/ where I found out about mecway.
So I decided to download it and try it out, given it has a forum and good support and a forum where I can ask questions about issues that I come across.
So after downloading the software, in order to understand how to use mecway I decided to read the manual and needless to say, I am getting a little overwhelmed with terms that I am not exactly familiar with by chapter 6.
I guess I need help.
Thank you for reading.
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Comments
Regarding chapter 6, I'll try to summarize all the mechanical analysis types in terms of vehicles:
Static - Least powerful. Essentially Hooke's law (F=kx) generalized to 3D. No momentum and no displacements large enough to change the stiffness, which typically means no displacements big enough to see. Example uses: Finding the stress in a space frame or stiffness of a car body in normal use.
Nonlinear static - Everything Static does (except a few odd features) plus large displacements such as suspension travel and large strains such as denting panels.
Nonlinear dynamic response - Everything that Nonlinear static can do (except some odd features) plus momentum. The most powerful and, in principle, makes all everything else in this list redundant. You could use it for a crash simulation. A downside is that it's slow.
Dynamic response - Includes momentum but only small displacements like Static. Maybe useful for finding stress due to vibrations induced by the engine or driving over rough ground.
Modal vibration - Finds free vibration modes independent of any applied forces. Might help to estimate how it vibrates or sounds when hits something. Also limited to small displacements like static but you can violate that restriction at the cost of accuracy.
Thank you for framing it in terms of vehicles, it helps a lot!
It's just specific terms like "stress-strain relationship" & non-linear that I have trouble grasping the understanding of.
Edit: I am also fairly illiterate when it comes to mathematical equations and algebra in general. I can use it to a degree, but I fumble around a LOT with the basic stuff.
But there's also terms such as DOFs (abbreviated from Degrees of Freedom), displacement and Buckling that may need clarification.
It seems to me that there could be a missing section to the manual which explains the terms and what they mean either before entering the main body of the manual or a glossary at the end listing everything in alphabetical order with a description mentioning everything with a slightly different way of phrasing what the words mean.
I feel that the following chapters (chapters afgter 6) within the manual would build ontop of what the current chapters (the chapters prior to 6) are saying.
Therefore I feel that understanding these concepts are necessary to get an overall picture of what the manual is trying to say in order to proficiently use the software to get the results I am looking for.
It might be easier to learn about general FEA concepts somewhere else. Or jump in with some of the tutorials to get more of a feeling for it.
Although because I am new to FEA as a whole, I do struggle to tell which terms are specific to mecway itself or general engineering terms.
When it comes to DoF, you're fine.
I think even if I do have to look elsewhere, a glossary at the end of the manual would be extremely helpful even if I have to look up what they exactly mean elsewhere just to confirm what I have been told is the same thing that the manual is talking about.
I say at the end because of the fact that it wouldn't disrupt the flow of the manual and what you're trying to achieve with it.
Thank you though.
Edit: I am extremely grateful that I found this software. It feels like this is exactly what I am looking for.
The essence of those "specific terms" you mention can, from time-to-time, give a few of us around here trouble as well
When I read your earlier posts I thought to reference the basic fundamentals in (at least) the following subjects:
That's a short list, but a beginning in structural concepts. A "nutshell" or "summary" search in the above areas should illuminate many of your questions.
Most of us with an engineering backround were told time & again to have an alternative analysis to compare the (computer) solution to -- usually a hand calculation. It's proven invaluable to predict (calculate) an approximate solution before hitting the SOLVE button. (Conversely, it also helps to recognize a bad solution.) So, if you haven't already, take a crack at a few of those practice problems you see and build your confidence!
Old engineering advice, freely given. Looking forward to hearing how your hobby develops.
Welcome to the forum.
~cwharpe
Thank you for understanding, not really too sure what you mean by the first paragraph though.
When you mention the basic fundamentals, do you know of any reading material that I can look up to know more about them and if so, would it apply to Mecway?
I was hoping that Mecway could help me avoid a lot of my mathematical illitracy (I have a lot of issues with algebra...), but yeah... As you put it, It is better if you know how to perform the calculations yourself by hand prior to running the simulation.
I guess where do I start?
Then I would read up on statics, possibly "statics for dummies".
Then I would move to mechanics of materials, possibly "mechanics of materials for dummies"
During this effort I might play around with very simple simulation programs intended for High schoolers and under, perhaps the west point bridge design program
https://stem.northeastern.edu/programs/ayp/fieldtrips/activities/wpbd/
https://sourceforge.net/projects/wpbdc/
You might hunt for additional material in google under "statics for children" or "mechanics of materials for children"
Something like this may, in fact be all you want.
Don't be put off by the focus on children, it is just that they are the ones that want to learn the same things as you these days, but have little mathematics background. Be aware that it is only in the last 200 years of the past 5000 years of building that mathmatical methods have been applied to structural calculation, and as late as the 1920's that the famous architect Gaudi used ancient non-mathematical methods to design his whimsical structures.
I think Mecway or Calculix are way too advanced to start on, though some of the simple tutorial problems in Mecway might be good eventually.
michael
Reading Materials:
I agree with @MikeMcMullen on the "### for Dummies" or any other summary stuff you can get your hands on, whether online, Youtube, trip to the local library. Examine the worked-out problems, maybe Chaps. 1-3? Maximum moment & shear. Maximum Stress. Factor of Safety. Allowable stress & displacement. Stress concentrations. Buckling. Etc., etc.
Side Note: Constraints/DOF -- Matters how you hold it. A problem in FEA is UNDER-constraint -- some solvers choke, others report wild results. See Douglass L. Blanding work "Exact Constraint: Machine Design Using Kinematic Principles". Again, the first couple of chapters gets you going. He has this simplified chart illustrating bars w/ ball-joint ends constraining rigid bodies (cubes). I wish I could show you (copyright laws). Couple of weak web references on that:
I'm no FEA master, but trying to simplify the Engineering basics here for you. Because when you DO solve a model how to interpret all those numbers? What do they mean? Are they reasonable? Is my model right? Can I defend my choices in this design? How does this impact safety?
~cwharpe
P.S. Thinking about your original objective reminded me... Some years back one of my colleagues was playing around with "Working Model Design Simulator." Can't say it was cheap, but it did have some 2D physics and crash simulations.