The spectrum decomposition method for generation of in-equipment response spectra

The Spectrum Decomposition Method has been developed for generating the in-equipment response spectra for seismic qualification of electrical equipment assemblies. The method models the floor spectrum-compatible waveform with a collection of uniformly spaced simple waveforms such as sinusoids, sine beats and decaying sines. Each simple waveform is then amplified through the dynamics of an equipment assembly and the total effects are combined with the square-root-of-sum-of-the-squares criterion to obtain the in-equipment response spectra. Step-bystep procedures are provided. Numerical examples are used to compare the results from the present method and those from time history analyses.