Research on the time-varying response spectrum method of seismic dynamic responses

A new method is put forward to establish the response spectrum arrays of time-varying seismic dynamical response by means of time-interval of SDOF (Single-Degree-Of-Freedom) time-history seismic reaction. In comparison with the traditional method, a prominent feature of these arrays is a better representation of the non-stationary time-varying characteristics of the response spectrum, such as the types, peak values and peak frequencies. Results show that the envelope lines of response time history are identical to the ones of step-by-step integration, and that the trends of amplitude variation with time are also identical. The values of response spectrum are smaller than the standard spectrum computations and greater than the time-history method, which is consistent with the theoretical prediction.