RAM Concept calculates the cross section forces about the design centroid of the cross section (after trimming has been taken into account).

For each of the same slab elements that make up the initial concrete cross section (before trimming has been taken into account), the elements’ nodal forces (for all the elements’ nodes on one side of the design section) are transformed to the centroid of the final concrete section and added to the design section forces. For slab elements that contain the end of the design section, only a fraction (proportional to the length of the design section in the element divided by the length across the element along a line collinear with the design section) of the nodal forces are included.

Nodal forces are used in place of integrations of slab stresses because slab stress results may have local spikes caused by odd-shaped elements. These local spikes can significantly alter the total integrated value. The nodal forces used by RAM Concept are not affected by the local stress spikes and always give results that will be in equilibrium with the nodal loads.