PreD 
Drift
Controlled Preliminary Frame Design

Using this program, you can obtain preliminary values of frame member section properties required to satisfy drift and strength requirements. Using the preliminary design procedure by Mahin and simple plastic analysis, the elastic section modulus (S), plastic section modulus (Z), and effective moment of inertia (I) can be determined and used to select initial beam member sizes. Strong columnweak girder design is assumed and it is the responsibility of the user to satisfy this assumption by selecting beam and column sections appropriately. Results given are for beam section properties. Please note also that the value of S for gravity loadonly case is based on beam fixedend moments, and that the moment for the distributed load case is calculated using the ACI approximation wL^2/11.