Comments Questions and Answers about the "Section ID" tab on the Input Grids In AutoPIPE
Item #1:
Logged: June 2014
When entering Beam Section Properties, the dialog will automatically calculate the "Section Properties" for Shapes = Pipe or Solid pipe based on "Section Dimensions" entered, but will not do that for any other shape selected. Why?
Answer:
Pipe is a round geometrical shape that is easy to calculate the area for solid circle or hollow circle shape and thus section properties. However other Beam shapes (i.e. M-shape, Channel, Tube, etc..) are more complex shapes with to many unknowns (i.e inside radius, champher, etc..) to easily calculate the area and thus section properties. Therefore, only Solid pipe and Pipe shape have their section properties automatically calculated. All other shapes the user must enter in user defined values.
Item #2:
Logged: Aug 2014
The standard Dutch rectangular section PS80X12 has what appears to be the wrong Torsion inertia. The value shown in AutoPIPE (512,000) looks like the sum of IYY + IZZ (polar moment of inertia) rather than Saint Venant's constant which is 41,720mm^4. Furthermore the data for Iz in the mdb file is fine. Why is the data not being read directly from the table.
Answer:
As mentioned in Item #1 above about why some values are automatically calculated and other are not. PS80X12 is a rectangle where the values, like torsion inertia, are calculated by the program.
In this case, AutoPIPE V8i 09.06.01.x and lower, internally calculated the torsional inertia in in^4 after conversion from mm^4 in database. This calculated value was slightly above an internal threshold (ex. +0.0023) that is concerned with only 2 significant digits (ex 4.0) instead of 3-4 required by this calculation (ex. 4.0023). The 2nd internal equation calculates the same value as found in the chart (ex. 41.720 mm4). However due to threshold check, this value is discarded and in turn the value available in the section database (ex. 51.2 cm^4) is used instead. This issue has been logged and to be updated in a future version of the program.
Workaround, after selecting the beam from the library, check "Non Standard" radio button and manually update the Torsional Inertia field with the correct value.
Found in Build = 09.06.01.19
Fixed in build = TBD
Logged = TFS-D146023