Spanos, Pol D.Matteo, Alberto DiZhang, HanshuYue, Qingxia2024-08-022024-08-022024Spanos, P. D., Matteo, A. D., Zhang, H., & Yue, Q. (2024). Bivariate Processes Evolutionary Power Spectral Density Estimation Using Energy Spectrum Equations. Journal of Physics: Conference Series, 2647(25), 252009. https://doi.org/10.1088/1742-6596/2647/25/252009https://hdl.handle.net/1911/117565In this paper a novel procedure is developed for evolutionary cross power spectra (ECPS) estimation of bivariate nonstationary stochastic processes. Specifically, the ECPS is determined by estimating the statistical moments of energy-like response quantities of lightly damped linear filters excited by nonstationary stochastic processes. In this context, a smoothing procedure is incorporated by using the Savitzky-Golay (S-G) moving average filter to obtain reliable ECPS based even from a limited number of available records. Further, a refinement of the approach is proposed relying on polynomial based functions of the system output. Several numerical examples, including nonstationary processes with known spectra, and historic accelerograms are used to assess the reliability and accuracy of the proposed procedure.engExcept where otherwise noted, this work is licensed under a Creative Commons Attribution (CC BY) license.  Permission to reuse, publish, or reproduce the work beyond the terms of the license or beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.Journal articleSpanos_2024_J_Phys__Conf_Ser_2647_252009https://doi.org/10.1088/1742-6596/2647/25/252009