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

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