Generation of endurance time excitation functions using spectral representation method

In this study, application of the spectral representation method for generation of endurance time excitation functions is introduced. Using this method, the intensifying acceleration time series is generated so that its acceleration response spectrum in any desired time duration is compatible with a time-scaled predefined acceleration response spectrum. For this purpose, simulated stationary acceleration time series is multiplied by the time dependent linear modulation function, then using a simple iterative scheme, it is forced to match a target acceleration response spectrum. It is shown that the generated samples have excellent conformity in low frequency, which is useful for nonlinear endurance time analysis. In the second part of this study, it is shown that this procedure can be extended to generate a set of spatially correlated endurance time excitation functions. This makes it possible to assess the performance of long structures under multi-support seismic excitation using endurance time analysis.