Material units

Discussion in 'SolidWorks' started by Chris Dubea, Mar 7, 2006.

  1. Chris Dubea

    Chris Dubea Guest

    To begin our conversation, I am using SolidWorks 2005 SP3.

    I'm writing a software tool to manage SolidWorks materials a little
    more easily that the included tools and I'm flummoxed. The material
    data is kept in data files ending in .sldmat. These are basically XML
    files which makes them fairly easy to parse and manipulate.

    What I don't understand is the units. Lets take the ultimate and
    yield strengths as an example.

    In the solidworks materials.sldmat file, lets look at AISI 304.

    Just for grins, set your units to IPS.

    Pull up AISI 304 in the edit material gizmo

    The Tensile Strength is 74,987.0 lb/in^2
    The Yield Strength is 29994.8 lb/in^2

    Now open up solidworks materials.sldmat in a text editor.

    Find AISI 304 and if you look further, it contains the two lines:

    <SIGXT displayname="Tensile Strength" value="4.20507E+8"/>
    <SIGYLD displayname="Yield Strength" value="3.51571E+8"/>

    Okay, doing some simple proportioning (to get an idea of what the
    conversion factor might be)

    4.20507E+8/74987 =5607.7...

    and

    3.51571E+8/29994.8 = 11721.1...

    WTF?

    Now, assuming that the units in the solidworks materials.sldmat file
    for stress would be kilopascals (for a well behaved metric unit), to
    convert from psi to kilopascals to psi you would multiply by 6.894, so
    that's not it.

    Okay, assuming the units are in N/mm^2, converting from psi to N/mm^2
    you multiply by 6894.757

    Now my head really hurts.

    Does anyone have a clue what in the world is going on?

    Thanks
    ===========================================================================
    Chris
     
    Chris Dubea, Mar 7, 2006
    #1
  2. Chris Dubea

    krupnikas Guest

    How about SMOOTS?

    Oh sorry thats length..
     
    krupnikas, Mar 7, 2006
    #2
  3. Chris Dubea

    That70sTick Guest

    Create a material with nice round numbers for stress values and see
    what results.
     
    That70sTick, Mar 7, 2006
    #3
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