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wolfram-mathematica

How to convert outputs into units of stress intensity (MPa sqrt[meters])

The stress intensity at crack tips is commonly described in terms of MPa sqrt[m]. This is a difficult unit, and Mathematica prefers to return answers in sqrt[J]sqrt[MPa]/m, for which the numerical value is 1000x larger.

This can be confirmed with:

   Quantity[1, (Sqrt["Joules"] Sqrt["Megapascals"])/("Meters")]/ Quantity[1, "Megapascals" Sqrt["Meters"]]

The most obvious solution: 

UnitConvert[Quantity[1, (Sqrt["Joules"]*Sqrt["Megapascals"])/
  "Meters"], "MPa m^0.5"]

Just returns the input. I would like an output in the form:

Quantity[0.001, ("Megapascals"  Sqrt["Meters"] )]

Any suggestions?

Solution

  • How about

    u = UnitConvert[
  Quantity[1, (Sqrt["Joules"]*Sqrt["Megapascals"])/"Meters"], 
  "Megapascals" Sqrt["Meters"]]

InputForm @ u
(* Quantity[1/1000, "Megapascals"*Sqrt["Meters"]] *)