A discontinuous cantilever beam analogy for quantifying higher mode demands in stacked rocking cores

Abstract

SummaryStacked rocking core (SRC) combinations are innovative sustainable structural assemblies that mitigate seismic demands through uplift at the hinge joints and direct damage to replaceable fuses. The stacked segments curtail substantially higher mode effects by the relative motions between multilevel cores. Currently, few research studies have quantified the behavior of SRCs under earthquake shaking. This paper presents a novel closed‐form solution for quantifying the higher mode demands of stacked braced frames subjected to seismic excitation. The mathematical formulae for modal analysis are derived using the analogy of discontinuous cantilever beam and Euler–Bernoulli equation. The proposed equations provide a method for rapid analysis and preliminary design of low‐ to mid‐rise SRCs. A parametric study is carried out to investigate the influences of rotational restraint of segments and the location of the rocking joints. Results verified by time response analysis indicate the validity and accuracy of the suggested formulae.