Research on a Building under Multi-dimensional Seismic Excitations

For a building under multi-dimensional seismic excitations, a new random vibration analysis based on equivalent excitation method is presented, in which, a new equation of motion of the building is used to depict its dynamics and kinematics features. Since most of the earth shocks are non-stationary random processes, the input power spectral density of the seismic excitations are modulated by a time varying function, and their equivalent excitations are constructed by using continuous wavelet transform, where the continuous wavelet coefficients are calculated by using scales and the evolutionary power spectral density, while the equivalent excitations are constructed by inverse continuous wavelet transform. The random vibration analysis is carried out following the procedures of the equivalent excitation method. A simulation example is given to investigate some affection of the multi-dimensional seismic inputs, especially the rotational one.