A comparative analysis of frequency- and impulse-based substructuring for experimental shock response predictions

Frequency-based substructuring has become widely adopted in experimental settings due to its ease of use, and counts numerous successful applications. In the analysis of shock and initial response peaks, however, a frequency domain prediction might be erroneous due to the artifacts of the Fourier transform, such as the forced periodization. The issue might be addressed via impulse-based substructuring, the time domain counterpart of the frequency-based formulation, which utilises impulse response functions and linear convolution for the coupling process. This article presents a comparative analysis of frequency- and impulse-based substructuring techniques in the context of experimental shock response predictions. First, time and frequency domain deconvolution algorithms are discussed and compared on a numerical example. Then, the outcome of a substructuring prediction is demonstrated in an experimental coupling scenario. Both a one-dimensional rod and a multi-dimensional virtual point coupling applications are presented.