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.
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.
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
Welcome to engineering, where we have MPa as a unit of stress and mm/mm as a unit of strain!
mm/mm?? why not call it m/m?
Because we’re precise!
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.
How is it more practical when 1 m/m = 1 mm/mm = 1 μm/μm?
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.
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
Why km/h (or mph) and not ft/year? Because the numbers have a nicer magnitude then.
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
I feel like I should’ve spotted that… they’re the same units. 🤦
I was told that you also sometimes have four basis vectors in 3D