Moment of inertia for Concave Polygon

AI Thread Summary
To calculate the moment of inertia for a concave polygon, triangulating the shape is a viable approach, allowing for the summation of the moments of the individual triangles. An alternative method involves decomposing the concave polygon into two convex polygons, where one represents the material and the other represents the void, combining their moments with opposite signs. This discussion highlights the importance of these techniques in simplifying the calculation process. The user expresses gratitude for the clarification on these methods. Overall, triangulation and decomposition are effective strategies for determining the moment of inertia in concave polygons.
SaadAhmad
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[SOLVED] Moment of inertia for Concave Polygon

While working on a simulation I ran into this problem. I'm trying to calculate the moment of inertia for a concave polygon. The polygon is made of N vertices (Also the edges are straight lines). I've done a bit of researching however I've only found resources for convex polygons.

I'm thinking of triangulating the polygon and then going from there, but I don't know how to actually use it.

I will be grateful for any help on a general way of calculating the moment of inertia for a concave polygon


Saad
 
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If you triangulate the polygon, can't you just sum the moments of the triangles? In the case of simple polygons you can also use the trick of trying to decompose it into two convex polygons, where one is the place where material is, and the other is the place where it isn't and add them with opposite signs.
 
Ah yes, I was over thinking it. Thanks for your help
 
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