THE TRANSIENT-RESPONSE OF STRUCTURES USING ASYMPTOTIC MODAL-ANALYSIS

The transient response of a structure is predicted using an asymptotic modal approximation of the classical modal solution. The method is ai med at estimating the impulse response problem for high frequency regi mes where typical numerical methods (e.g., finite elements) are imprac tical. As an example, the response of a thin elastic panel is modeled in a frequency range that includes a sufficient number of modes. Both impulsive and arbitrary forms of excitation are considered. It is show n that the asymptotic modal analysis yields an excellent estimate of b oth the local displacement near the excitation location and of the spa tially averaged transient response of the panel for moderate time span s after the excitation is applied. Furthermore, as this approach does not require that the mode shapes or natural frequencies of the structu re to be calculated, it is an extremely efficient technique.