Computation of Fundamental Time Period for Moment-Resisting Framed Steel Buildings

The paper presents an analysis of symmetrical steel moment-resisting framed (MRF) buildings to estimate the time period of vibration of the considered models of the buildings of varying height up to 5 storeys. The formula for the time period of the bare steel MRF building is given by the design code IS 1893(Part 1): 2016 in seismic analysis of the structures, but it is in the form of the height of the building as a primary factor. Many researchers have performed the studies to evaluate the time period of the steel MRF buildings and found that the different other parameters such as stiffness of the structure and base dimensions are also the influencing factors. It seems necessary to consider the effects of some other parameters of the structures also in the evaluation of the time period values. The paper presents the results of the analysis for the effects of the various parameters on time period of the building, i.e. stiffness of the structure, slab thickness for a particular number of bays in either direction, plan dimension, or plan area of the building. In the paper, different values of the time period have been obtained by dynamic analysis on considered building configurations for earthquake zone-III and presented the comparative analysis of period values concerning the code IS-1893.