HI All-

I am looking for the formulas (programmed in excel or not) for the second moment of the area (inertia) for a circular segment in a hollow pipe. I believe there is a spreadsheet solution for a solid pipe but I need the formulas for a hollow pipe with a solid flat topped circular segment, with a height < the radius (flat top with a curved bottom to match the pipe radius). This is for a small weir to be installed within a pipe.

Any ideas, solutions or places to look for these formulas is greatly appreciated.

Thanks for this great site, Roger

You could use the 'Points' worksheet in Alex Tomanovich's SECTPROP.xls this will give you an answer pretty quickly.