(Click here for better image of Matlab GUI screenshot)
I have added an “Exponential Decay” option to the wavelet synthesis function in the Matlab GUI package. The goal is to synthesize a wavelet series that has a gradual overall exponential decay, somewhat similar to an actual pyrotechnic or seismic shock event. Here is an example.
The advantage of using wavelets as a basis is that each has zero net velocity and zero net displacement, as does a complete series. These conditions are needed for both analysis and testing.
Note that some pyrotechnic SRS specifications begin at a natural frequency of 100 Hz. A good practice is to extrapolate the specification down to 10 Hz, especially if there are any vibration modes below 100 Hz.
The Vibrationdata Matlab GUI package is given at: Vibrationdata Matlab Signal Analysis Package
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I previously came up with a method which synthesized a series of damped sines to satisfy an SRS. The damped sines where then decomposed into a wavelet series. The previous method is still available. See Webinar 27 – SRS Synthesis
– Tom Irvine