ABSTRACT
The efficacy of lateral load patterns (LPL) to estimate the responses of semi-rigid (SR) frames using nonlinear static analysis (NSA) is investigated by comparing their assessment with the standard response, evaluated from nonlinear response history analysis (NRHA). A 5-Story low-rise steel semi-rigid frame is selected as an illustrative example for NRHA, considering the far-field and near-field with forward-directivity earthquakes. The sensitivity of three LPLs is compared based on target displacement (Td ) approach by selecting two Td values, which represent the elastic and elastic-plastic states on the pushover curve of the SR frame. The seismic response parameters included peak-story displacement, maximum inter-story drift ratio, the number of plastic hinges, and their SRSS values. The results show that (i) the estimated error in seismic responses from different LPLs relies upon the state (elastic and elastic-plastic); and (ii) the conventional mode based load pattern is found more suitable for low-rise steel frames.
