The math behind mass properties

Discussion in 'SolidWorks' started by Brian, Mar 14, 2005.

  1. Brian

    Brian Guest

    I am in the process of writing either a macro or vb standalone to design
    a part one of whose design criteria is volume.
    The part is basically a revolve. It consists of 6 design criteria
    dimensions + design volume. That leaves one dimension as the only variable.
    I have been estimating the initial variable, checking mass properties,
    adjusting, rebuilding, rechecking volume, ect until I get it close enough.
    The part revolve is made up of a series of tangent arcs and lines so
    doing the math by hand would take much longer than guessing until correct so
    I would like to macro the funtion as I do it quite often ( alter cumbustion
    chamber volume to adjust for desired compression ratio ).
    The issue that I am having is that I can't seem to find any sites/books
    that have the formulae that I'm after. Is anyone able to direct me to a
    source?
     
    Brian, Mar 14, 2005
    #1
  2. Several years ago there was a scuba tank model that allowed you to specify
    some parameters and then let Excel solver determine the optimal size to
    maximize the volume while minimizing the weight. I think this is really
    what would do what you want to do. Unfortunately, I don't have a copy -
    anyone else?

    WT
     
    Wayne Tiffany, Mar 14, 2005
    #2
  3. What you probably want is the volume of a solid of revolution. There
    are two main ways to find this using integrals, both are explained at
    http://mathworld.wolfram.com/SolidofRevolution.html

    If you do a search on "volume solid revolution", you'll find more
    sites. The basic thing is knowing a function of the shell. You will
    probably need to apply some numeric integration method if you can't
    come up with an antiderivative of your curve. Look for information on
    Simpson's rule, or the trapezoid rule. Here's a page with some links
    to more information about numeric integration methods:
    http://mathworld.wolfram.com/NumericalIntegration.html

    If you need more help, if I could know the curve that you're revolving,
    I could probably give you a formula.

    Hope that helps,
    Jonathan Anderson
     
    Jonathan Anderson, Mar 14, 2005
    #3
  4. Brian

    Brian Guest

    Those are the formulae that I was after. I now recall seeing them about 10
    years ago in book form, and being very intimidated. Thanks for the links.
    Maybe this time I'll attempt to tackle the problem.
     
    Brian, Mar 15, 2005
    #4
Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.