Indian Journal of Science and Technology

Abstract

Background: A steel frame system becomes structurally less efficient when subjected to large lateral loads such as a strong wind, earthquake. Many research efforts have been made to develop more efficient structural systems with better resistance against strong lateral loads. Methods: An attempt is made in this direction by both analytical and experimental studies. A bare steel framed model of size 4m x4m is chosen for G+2 storey with columns of height 4m. The particular frame is scaled down to 1:11 scale to perform shake table test for seismic zone-V in terms of modal frequencies. Same frame is modelled in Hypermesh software & analysis is done in Nastran and ETABS software’s. The results obtained can be applied to 16 X 16m G+9 Multi-storeyed commercial complex structure and analysed in ETABS software for Base shear, response spectrum and pushover analysis to assess the performance of the structure. Findings: Prototype of G+2 storey scaled down model, ETABS and Nastran analysed models showed approximately same values of modal frequencies 10- 12% which is an allowable percentage. Novelty: The results obtained shows that the base shear, performance point of the structural system and in terms of model frequencies are with in safer limits. The overall performance of the structure was found to be safe between operational to collapse stage. Advantages: The present work gives the dynamic behavior of bare steel frame subjected to lateral loads which helps in assessing the damage causing due to earthquake can be pretended to prevent the loss of life.

Keywords: Bare steel frame; Shake table; Base Shear; Response spectrum; Modal frequencies