Inappropriate SRS specifications

摘要

The Shock Response Spectrum (SRS) is a fairly simple concept that has been used successfully for many years, but occasionally falls victim to the inexperienced user. In many cases, this occurs when a test specification wrongly attempts to exploit SRS features. One such case was trying to make the SRS a narrow-bandwidth signal detector, a job that is better accomplished by Fourier methods. With zero damping, the SRS does indeed behave like the Fourier transform and it was thought that the SRS could be used to isolate very low amplitude, short duration and single frequency product resonances caused by a velocity shock. In trying to accomplish this, damping was reduced to almost zero, thereby producing maximum gain of the filter and many SDOF filters were used over a linear plot to provide FFT-like resolution. However, some knowledge of transmissibility (response) curves reveals some problems with this approach.