Abstract: | A response spectrum method which combines the analytical advantage of the mode acceleration formulation and the practical advantage of the mode displacement formulation is developed for seismic response calculation of non-classically damped structures. It reduces the error associated with the truncation of the high frequency modes without explicitly using them in the analysis. The method is especially effective for calculating the response of stiff structural systems and also for calculating the response quantities which are strongly affected by high frequency modes. Even with flexible structures, it is shown to provide more accurate response results than the results obtained with the mode displacement approach. |