Replicate hand calc to mecway

UGMENTALCASEUGMENTALCASE

Morning all,


I may be way off here, and forgive me if I am, just trying to learn a bit more. I've dug out my old HNC book from college where it talks about calculating stresses and strains, and I've got reading it and trying to follow it again, and refresh my brain!

I've attached a couple of images of the pages I've worked through. I've worked the examples and understood what they are talking about. Is there a way to put this into practice in Mecway? If so could someone please give me a short walk through? I have done it myself last night, but as I'm learning the basics, I've probably selected the wrong analysis type or something, my results weren't the same.


All I was thinking was to try and understand more I get some more examples like the attached and then use Mecway to check results? I've heard things can work out a little different but worth a try?


Thanks in advance.

Comments

  • VictorVictor
    Here's the example from the book with results that match all the digits shown in the book for strain and displacement.

    You may already know this but a key difference is that if you apply opposing forces like the book shows, they have to be exactly balanced or there'll be a tiny acceleration that causes it to fly away forever (Newton's 2nd law) and not produce a static solution. Even if they are balanced, they leave it with freedom to move around (Newton's 1st law), which again doesn't give a unique static solution. So instead, we replace one of each pair of forces with a constraint and let the solver find the reaction force. In general, this isn't quite correct because the force allows the surface to deform out-of-plane while the constraint doesn't. But in this case, there isn't any such deformation, so it's correct.

    The solution includes strain values which are disabled by default. To get them, turn on Tools -> Labs -> Output strain on solid elements.

  • UGMENTALCASEUGMENTALCASE

    Victor, thanks for your time. I must have something wrong with my set up! I'll go back over it and double check things.


    Thanks again

  • AndreaAndrea
    Youcan try to solve using symmetry because the problems shows simmetic loads and geometry. Studyng a quarter of plate the results are (more elements C3D20):

    DX = 2 x 0.002683 = 0.005366
    DY = 2x 0.01171 =0.02342

    PS
  • UGMENTALCASEUGMENTALCASE
    Awesome! I've not fully got back to it yet, but I'll hopefully have more time over the week end. I want to move on to trying other simple set ups as well, and work thriugh hand calcs and then prove them with the software.

    Thanks again! :-)
  • AndreaAndrea
    You can calclulate your own theoretical solution using two books:

    Peterson's stress concentration factors
    Roark's formulas for stress and strain

    or Timoshenko's  Books.
  • UGMENTALCASEUGMENTALCASE

    I'm looking at them now thank you . Would you say they are fairly understandable books for a beginner? Or am I barking up the wrong tree?


    Cheers

  • AndreaAndrea
    The firsts are for pratical applications.
    Timoshenko's books are theoretical books but with solved examples.
    I don't know if you're an enigineer but are suitable for engineers because is necessary have a background of various matters: mechanic of materials, machine design, mathematics.
  • UGMENTALCASEUGMENTALCASE

    Hi yes I'm a toolmaker by trade, had various other books similar to this going through my college years! I've got them downloaded via Scrbd website, so I can get reading up on them.

    If they are going to be of use to others on here, I can upload them somewhere?

    Thanks :-)

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