Kurtosis transfer in MDOF systems under amplitude-modulated Non-Stationary Non-Gaussian Excitations: A Frequency-Domain decomposition approach

作者：Wuyang Lei, Yu Jiang, Yawen Tian, Hongbo Tang, Jinhao Zhang · 发表于：Mechanical Systems and Signal Processing · 年份：2025 · DOI：10.1016/j.ymssp.2025.113059 · 被引用次数：3 · 研究领域：Image and Signal Denoising Methods、Advanced Fiber Optic Sensors、Fault Detection and Control Systems

Non-stationary non-Gaussian random vibrations, frequently encountered in aerospace, mechanical, and civil systems, often induce transient structural responses with complex and unpredictable dynamics. Kurtosis, a key statistical measure of signal impulsiveness, plays a dual role in characterizing such transient behaviors and assessing vibration fatigue damage. This study develops a kurtosis transfer model for multi-degree-of-freedom (MDOF) systems under amplitude-modulated non-stationary non-Gaussian excitations, assuming the excitation spectrum sufficiently covers the system’s modal frequencies to induce resonance-dominated responses. The proposed framework reveals how kurtosis is selectively transmitted through specific modal pathways by establishing a mathematical relationship between frequency-domain excitation substructures and the resulting response kurtosis. In addition, a phase modulation strategy is introduced to adjust the non-Gaussian properties of decomposed excitation signals, thereby enabling active control of the system’s response kurtosis. Numerical simulations and experimental validations confirm the model’s predictive accuracy. The resulting methodology offers a physically interpretable and computationally efficient framework for known vibration systems, supporting both dynamic analysis and the design of excitation signals with targeted kurtosis levels for accelerated vibration fatigue testing.