Accuracy analysis of a simplified algorithm for seismic response analysis of two supports structures under multi-support excitation

On the base of response spectrum CQC method considering all the coupling items, an approximate SRSS algorithm ignoring relevant coupling terms was given. Due to the specialty of structures with two supports, a simplified algorithm for analysing quasi-static response of this type of structures was put forward. Taking a typical two supports structure as example, the accuracy of the approximate algorithm of SRSS was analyzed. The results show that the error of SRSS method mainly comes from ignoring quasi-static and relative dynamic coupling terms, but not modal coupling terms. The stronger the traveling-wave effect is, the bigger the error of the approximate algorithm will be. But according to the calculation results of actual engineering structures, within the range of the common wave velocity, the computation errors of displacement and internal force of the two approximate algorithms keep within 10% and 15% respectively. So it is feasible to use approximate algorithm of SRSS for seismic response analysis of two supports structures under multi-support excitation. ©, 2015, Chinese Vibration Engineering Society. All right reserved.