The program calculates the Sum of X-Forces Σ(FX), the Sum of Y-Forces Σ(FY) and the Sum of Bending Moments Σ(MZ) (at Point X=0, Y=0) for the whole Model, for the Nodal Loads, Elemental Loads, Acceleration (Body) Loads and the Support Reactions. All three Sums (see the last row of the table, in bold) have to be zero if the Model is in Equilibrium.
Important: If you see values other than zero in the last row (SUM, in bold), then there is a problem with the Model and the Model needs to be checked. The Model is probably a mechanism and any results should not be taken into account. This is already checked by the program, every time an Analysis is conducted, so theoretically it will never happen. But the calculations are there for you to check and verify.
Note: The sign convention is according to the Global Axes, as shown in the figure.
