Department of Civil & Environmental Engineering

The Pennsylvania State University

ABSTRACT

In seismic design of precast wall panel systems, one rational methodology involves use of the equal energy concept (EEC) assuming a reasonable pattern of inelastic deformation at some joints connecting rigid body elements. In this paper, a methodology based on estimation of maximum inelastic displacement d_p from inelastic design response spectra (IDRS) as an alternative to using the equal energy concept (EEC) is proposed. The IDRS are developed using the linear acceleration step-by-step method for the analysis of a single degree of freedom (SDOF) model subjected to several earthquake records. The relation between response modification factor R which is defined as the ratio of the elastic strength demand (ESD) to the yield strength F_y and displacement ductility demand which is defined as the ratio of the maximum displacement d_ep to the yield displacement d_y shown. The developed IDRS represent the average of the results from 15 California earthquakes. The plotted IDRS give ductility demands for R values of 2, 3, 4, and 5, damping ratios of 5, 10, and 15%, and strain hardening ratios of 0 (elastic-perfectly-plastic model) and 10% (bi-linear model). The methodology involves estimation of the fundamental period of the structure using a finite element model, a linear-elastic static analysis based on the equivalent lateral static load method of BOCA or NEHRP provisions with an R value of 1.0 to calculate the ESD, and the use of IDRS to estimate d_p once the R value for the particular design under consideration is selected. The methodology is demonstrated for the case of a 10-story large panel coupled wall building is presented.