Nonlinear equivalent sdof analysis of steel frame structures using parameters estimated from recorded floor acceleration response: An experimental case study

Abstract

In practice, the building displacement response is often estimated from acceleration using double integration due to the expensiveness and difficulty of measuring displacement. However, a high-pass filter is needed to eliminate the low-frequency component due to the existence of indistinguishable lowfrequency noise that incurred during the double integrating process. As a result, the displacements obtained from accelerations may have large errors, especially when the structure has significant nonlinear deformation. This study aims to estimate the displacement response of steel frame structures by firstly estimating SDOF hysteretic parameters from the acceleration response data, and then by performing numerical analysis using the extracted hysteresis model. The proposed approach was verified using experimental data from shaking table test of three identical 5-story steel frame structures subjected to different seismic records. The results show that the SDOF analysis maximum displacement has higher accuracy than the equivalent SDOF maximum displacement estimated from recorded floor acceleration response data that is recently used for post-earthquake building assessment.