EFFICIENT SEMIANALYTICAL GENERATOR OF INITIAL STIFFNESS DESIGNS FOR STEEL FRAMES UNDER SEISMIC LOADING .2. SLENDER FRAME

A simple stiffness design formula including the effects of column elon gation is derived for a slender steel building frame. The steel frame has prescribed column cross-sections obtained in the companion paper ( Part 1) and the angles of nodal rotation at the beam ends related to t he net deformation of the beams under horizontal design loads are spec ified. This problem is a hybrid inverse problem with a subassemblage o f members of prescribed stiffnesses and a subassemblage of members of stiffnesses to be determined. It is shown that a set of beam bending s tiffnesses and the remaining frame deformation can be obtained through a set of simultaneous linear equations. The final design is then foun d for the design story shear force evaluated recursively. (C) 1997 by John Wiley & Sons, Ltd.