Influence of strength dependent stiffness on seismic design

Abstract

The conventional method of seismic design of structures considers the lateral natural period to remain constant during the design process. However, the relatively newly proposed yield point spectra based method instead considers a constant yield displacement as the primary criteria. This article provides a critical comparison of both of these methods through case studies. The conventional method is found to be safe but uneconomic, while the yield point spectra based method is challenging to implement and earthquake data specific. A new iterative technique is proposed in this article, which is based on the methodology of the conventional analysis process but takes into account the main feature of the yield point spectra based design, i.e., to maintain constant yield displacement by varying strength and stiffness accordingly. It is anticipated that the proposed seismic design method will appeal to the designers due to its procedural familiarity and conceptual superiority.