Software

Stockwell-Ditommaso-Ponzo Transform

Ditommaso R., Ponzo F.C. (2026). Time-frequency representation of nonlinear structural response through rationally sampled Stockwell analysis. Mechanical Systems and Signal Processing. DOI: https://doi.org/10.1016/j.ymssp.2026.114920. Link al documento: https://www.sciencedirect.com/science/article/pii/S0888327026010770. MatLab function: https://it.mathworks.com/matlabcentral/fileexchange/184677-sdp-transform-stockwell-time-frequency-analysis-on-a-record  

The method introduces a rational, canonical frequency grid that is independent of the signal duration, enabling the direct comparison of records acquired by different sensors, during different events, and from numerical simulations of the same structure. This property makes the representation particularly well suited to structural monitoring and to tracking the evolution of modal frequencies during damage and subsequent recovery. The methodology has been validated on synthetic signals, numerical models and real experimental data, including the response of a reinforced-concrete building during the 2002 Molise earthquake. The results show an accuracy comparable to that of the main reference time–frequency techniques, with the added advantage of greater reproducibility and comparability across different records. The SDP representation also enables the definition of physically interpretable indicators of the dynamic evolution of the structure, which can support automated identification and damage-assessment procedures. The work opens new perspectives for Structural Health Monitoring applications, multi-sensor analysis, the comparison of experimental data with numerical models, and the development of artificial-intelligence-based procedures.

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