private formula
The second moment of area, also known as moment of inertia of plane area, area moment of inertia, polar moment of area or second area moment, is a geometrical property of an area which reflects how its points are distributed with regard to an arbitrary axis.
The second moment of area for a shape is easier to be calculeted with respect to a parallel axis or with respect to a perpendicular axis through the centroid of the shape.
The formula calculates the moment of inertia of a disc or a filled circular cross section with respect to a horizontal axis through the centroid of the disc. (Parallel axis theorem)
| Ix | Area Moment of Inertia (mm4) |
| π | pi |
| D | Diameter of Rod (mm) |