Several building codes require eccentric loading on diaphragms to account for accidental torsion effects. Referring to models with rigid diaphragms, such eccentric loading is accomplished by simply shifting loads to a new position that accounts for eccentric distances. For instance, concentrated story loads for seismic load cases are first calculated at diaphragm's mass center and then they are applied at their shifted locations. For wind load cases, a similar procedure is followed: story wind loads are calculated based on building profiles (one for X and one for Y-direction) and then they are lumped and applied at their shifted locations.

On the other hand, for models with semirigid diaphragms, the above procedure is not applicable since such diaphragms are meshed and loads on these diaphragms are not concentrated at a certain location but rather they are distributed over the diaphragm for seismic\dynamic load cases and they are applied along building edges for wind load cases. To address these issues for semirigid diaphragms, different methods are implemented and they are explained in the following sections.