Kurtosis control of amplitude-modulated non-gaussian signals for fatigue test

Xu, Fei (author), Yang, Huixian (author), Ahlin, Kjell (author), Chen, Zhifeng (author)

The amplitude modulation method was used to generate non-Gaussian signals that acted as excitation for fatigue tests. The fatigue life of structures under non-Gaussian excitation has been proven to be closely related to the features of the amplitude modulation signal (AMS) and kurtosis of the structural response. In this study, the modelling of the AMS by Beta and Weibull distributions and the resulting kurtosis range problem is first reviewed. To solve this problem, a new method for creating an AMS based on a linear combination of Beta and Weibull distributions is proposed. To ensure that the high kurtosis of the amplitude-modulated non-Gaussian signal is correctly transferred to the structural response, the method is further developed to fulfil the specifications for the fatigue damage spectrum (FDS) by controlling the spectral content of the AMS. Herein, a Gaussian AMS with a low-pass cutoff frequency is first generated and then converted to a Weibull or Beta AMS based on the cumulative distribution function (CDF) transformation. The proposed method is verified using simulated and field-measured data. The results show that the full range of specified kurtosis is achieved with the new AMS modelling method. The high kurtosis of the non-Gaussian input signal can be transferred to the linear system response if the mean value of AMS during the period of the system impulse response is the same as AMS.

• Language: English
• Keywords: non-Gaussian signals, amplitude modulation method, fatigue damage spectrum, kurtosis
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: Str. 440-451
• Numbering: Vol. 70, no. 9/10
• PID: 20.500.12556/RUL-163915
• UDC: 539.3:620.1
• ISSN on article: 0039-2480
• DOI: 10.5545/sv-jme.2023.908
• COBISS.SI-ID: 211374595
• Publication date in RUL: 14.10.2024

Record is a part of a journal

• Title: Strojniški vestnik
• Shortened title: Stroj. vestn.
• Publisher: Zveza strojnih inženirjev in tehnikov Slovenije [etc.] = Association of Mechanical Engineers and Technicians of Slovenia [etc.
• ISSN: 0039-2480
• COBISS.SI-ID: 762116

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Title: Nadzor sploščenosti amplitudno moduliranega negaussovega signala za namene utrujenostnih preizkusov
• Keywords: negaussovi signali, metoda linearne kombinacije, metoda amplitudne modulacije, mejna frekvenca, spekter utrujenostnih poškodb, sploščenost