Speaker
Description
Impulse-based substructuring (IBS) is the time-domain counterpart of the well-established frequency-based substructuring method (FBS). The IBS method is especially suited for determining shock responses, where the main goal might be to correctly predict the maximum amplitudes, e.g., of the accelerations. Its advantages originate from it being a time-domain method, i.e., high-frequent content, potentially consisting of many modes, can be represented in a short time series.
While this method has been successfully applied for numerical models in the past, experimental applications are just now starting to be conducted. In the authors' previous work, it was shown that the IBS method can be used experimentally to determine the initial response peaks of aluminum and polyoxymethylene (POM) rods considered as one-dimensional, using a time domain deconvolution procedure to experimentally estimate the impulse response functions (IRF) and additionally downsampling with a low-pass filter for the POM rods. Whereas this showed that an experimental application of IBS is possible, the practical use-cases were limited to one-dimensional systems.
Therefore, the Virtual Point Transformation (VPT), commonly used within FBS to realize experimental 6 degree of freedom interface coupling, was adapted for the IBS method. The performance of the adapted IBS scheme using VPT is showcased in an experimental example. With the approaches shown, it is possible to correctly reconstruct the initial acceleration response peaks to impulse hammer impacts. The results show that combining a time domain deconvolution, downsampling with a low-pass filter, and the VPT fundamentally enables experimental substructuring of three-dimensional structures in the time domain using the IBS method.
