THE RESOLUTION OF CLOSE NATURAL FREQUENCIES IN THE IMPULSE RESPONSE AND SEVERE TRUNCATION EFFECTS

摘要

The limits of resolution of close natural frequencies in the impulse response are established for frequency response analysis by direct Fourier transform methods and some possible sources of error in the transient testing of structures with close natural frequencies are discussed. The effect of severely truncating the impulse response is investigated and a method of restoring the derived vector diagram to an acceptable form is discussed but the smoothing introduced is shown to affect the frequency resolution limits.