• nooneescapesthelaw
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      2 months ago

      Welcome to engineering, where we have MPa as a unit of stress and mm/mm as a unit of strain!

      • azi
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        2 months ago

        mm/mm?? why not call it m/m?

          • nooneescapesthelaw
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            2 months ago

            Doesn’t apply here, say for example i have a piece of steel with length 100mm and it stretches 10mm, is mm/mm the strain would be 0.1 mm/mm, in meters it would be 0.1m/m

            Really strain is dimensionless but occasionally people add units

        • Umbrias@beehaw.org
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          2 months ago

          Because practicality. Strain generally occurs across mm scales at most for most traditional tensile tests and relevant materials. Normally it’s actually much less than mm. Occasionally you see micrometers/micrometers.

          • azi
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            2 months ago

            How is it more practical when 1 m/m = 1 mm/mm = 1 μm/μm?

            • Umbrias@beehaw.org
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              2 months ago

              Because excel doesn’t have built in unit handling so when you enter in readings from the strain gauge you’ll probably enter them in what’s being reported.

              You can write the units of strain however you like, I often say ul for unitless.

            • nooneescapesthelaw
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              2 months ago

              The original specimens and data are usually in mm, not meters so mm/mm makes more sense than m/m, although you do have a point

    • TheOakTree@beehaw.org
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      2 months ago

      Agreed. Perhaps it was based on tensile stress? Tensile stress = deforming force / cross-sectional area

  • rustyfish@lemmy.world
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    2 months ago

    So what you are saying is, I have to eat more, get fatter, widen my area and therefore reduce the stress?

    Got it.