For the force calculation the forces on each element at the cutting
plane summed for each component j by
fa,j=i=1∑nfi,j
and for the moment calculation
⎩⎨⎧ma,xma,yma,z⎭⎬⎫=⎩⎨⎧mx,0my,0mz,0⎭⎬⎫+01/z−1/y−z/r00y/r00⎩⎨⎧fx,0fy,0fz,0⎭⎬⎫
where subscript 0 refers to the element cut position on the cutting
plane, giving a resulting moment of
ma,j=i=1∑nmi,j