Mode-based procedure to interpolate strong motion records of instrumented buildings

摘要

This paper examines the accuracy of a commonly used piece-wise cubic polynomial interpolation (PWCPI) procedure to estimate the motions of non-instrumented floors in buildings with significant stiffness discontinuities. It is shown that results from the PWCPI procedure may depend on the locations of instrumented floors. While the PWCPI procedure may provide good estimates of floor displacements, this procedure may not accurately predict story drifts and floor accelerations. Therefore, a mode-based interpolation (MBI) procedure is presented as an enhancement to the PWCPI procedure. The MBI procedure is shown to provide accurate estimates of the floor displacements, story drifts, and floor accelerations. Furthermore, results from the MBI procedure are shown to be much less dependent on the locations of instrumented floors. The mode shapes needed in the MBI procedure may be computed from the eigenanalysis of the building, estimated from the system identification of recorded motions, or computed from the approximate formulas for mode shapes.