Problem FEA for epoxy granite.


Results 1 to 7 of 7

Thread: FEA for epoxy granite.

  1. #1
    Member ardenum's Avatar
    Join Date
    Nov 2020
    Posts
    91
    Downloads
    0
    Uploads
    0

    Question FEA for epoxy granite.

    Hey

    Does anyone have any ideas how to 'reliably' run FEA on epoxy granite?

    Granite is non-isotropic
    Epoxy, I don't really know

    Together? No idea, a mix of both I guess?

    FEA doesn't really work for non-isotropic materials, for concrete, big companies have their own algorithms that they use.

    Any ideas?

    Similar Threads:


  2. #2
    Member peteeng's Avatar
    Join Date
    Jul 2018
    Location
    dum dum
    Posts
    2577
    Downloads
    0
    Uploads
    0

    Default Re: FEA for epoxy granite.

    Hi Ard,
    Granite and epoxy can be considered isotropic for the purposes of FE. Its mix will be isotropic as well. The issue is establishing an accurate youngs modulus to use. Typically the rule of mixtures is used to estimate an E. Its Poisson ratio will be 0.25 - 0.3 and this will not make a real delta either. The strains in machine parts are so small these things don't matter. Machines are designed to be very stiff. Stresses are in the order of 1-2Mpa so strains are tiny. Granite varies from 40-60GPa stiffness. Epoxy is about 2-3GPa. Have a look at CSA cement I think its superior. I'm about to make some parts using this. Epoxy is expensive but not stiff. CSA is 2200kg/m3 and 23-30GPa stiffness. Look up the Milli thread it gets discussed there. Peter

    FE is used for non-isotropic materials all the time. I do alot of composite analysis for yacht structures. Orthotropic solvers just aren't on desktop CAD yet as most people work in metals.



  3. #3
    Member ardenum's Avatar
    Join Date
    Nov 2020
    Posts
    91
    Downloads
    0
    Uploads
    0

    Default Re: FEA for epoxy granite.

    Thanks for the info. I did read through the entirety of your thread. I know the feeling of going in circles with machine design. That's what's been happening to me for the past 7 months too. When all components are co-dependant on each other etc. I did find a solution in the end, for going in circles. You start with the spindle, then you design an appropriate z_axis for it then x...etc. Most diy starts at the bed though. I think that's just inviting trouble.

    As for CSA, I'm a little on the fence when it comes to longevity, concrete in general develops cracks, sooner or later, it's just the nature of it. I'll be paying a close attention to your thread and your experience with CSA. Good luck.



  4. #4
    Member
    Join Date
    Mar 2010
    Location
    Us
    Posts
    32
    Downloads
    0
    Uploads
    0

    Default Re: FEA for epoxy granite.

    FEA of good quality epoxy/quartz castings is very reliable.



  5. #5
    Member
    Join Date
    Aug 2006
    Location
    Denmark
    Posts
    29
    Downloads
    0
    Uploads
    0

    Default Re: FEA for epoxy granite.

    Quote Originally Posted by castinite View Post
    FEA of good quality epoxy/quartz castings is very reliable.
    How do you do that in practice? What software etc? I would really like to get into this....

    /Thomas



  6. #6
    Member peteeng's Avatar
    Join Date
    Jul 2018
    Location
    dum dum
    Posts
    2577
    Downloads
    0
    Uploads
    0

    Default Re: FEA for epoxy granite.

    Hi Thomas - I do FE work commercially and use Strand7 and Simsolid. Most CAD systems these days come with basic FEA capabilities. Look at Fusion 360 for instance. FreeCAD has FE as well. Peter



  7. #7
    Member peteeng's Avatar
    Join Date
    Jul 2018
    Location
    dum dum
    Posts
    2577
    Downloads
    0
    Uploads
    0

    Default Re: FEA for epoxy granite.

    Hi Thomas - Rampf publish their material properties. Typical of mineral cast materials. Peter

    Attached Files Attached Files


Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

FEA for epoxy granite.

FEA for epoxy granite.

FEA for epoxy granite.