Section Properties

matthew_stacy

Has anyone written a feature script or found a free application that calculates section properties (area, second moment of area, etc.)?  Even if I had to export a DXF file of the section profile, that would still be better than a poke in the eye with a sharp stick.

From what I gather Onshape does not currently offer this capability.

MBartlett21

If you use extrude-cut, you should be able to get the properties from the remaining part + face.

matthew_stacy

@MBartlett21, I don't understand.  Please provide an example.

Suppose I have a rectangular cross section 2mm wide by 3mm tall and I want to determine the second moment of area to calculate bending stress for a given applied load. The second moment of area for that section is

• I = bh^3/12
• I = (2mm) x (3mm)^3 / 12 = 4.5mm^4

How do I get Onshape to provide that result for this example or more complex profiles?

brucebartlett

Any solutions for this?  I can't remember it ever being added.   I was hoping I could use the section tool, then select the sectioned face and get the section properties but doesn't look like that's here. 

alnis

A decent free workaround:

1. Section feature made by @MichaelPascoe: https://cad.onshape.com/documents/bdffe7bf48f3b4155e85d073
2. Export DXF
3. Drag'n'drop to online DXF property calculator: https://acube.xyz/ (free account required)

Just need to be careful that the units match, but this seems like a "probably good enough" workaround.