Clip Design For Tank Roof Rafters

I am designing rafter clip. I have found formulation in bednar book under line loads subject. In the rafter clip my understanding is that i will have one shear force, and one radial load. This is due to the rafters being at an angle. the shear force can be converted in moment, by multiplying it with width of clip. so now we will have one moment and one radial force and these can be used in the stress formula of bednar.
Kindly comment on my understanding
My questing is how can i calculate the reaction (shear force) load from udl acting on rafters?
i have seen one formular:
Radial Load transferred to the end of the rafter
Hr = (gu x 3.14*D2)/(4Ls*N) ; where gu is total load in mpa on roof(live+dead load), D is dia of tank, Ls is lenght of rafter and N is number of rafter
Please comment on this formula