광대역 정규 프로세스에 대한 주파수 영역 기반 피로해석법의 적용성에 관한 연구 I : 레일리 PDF
Study on Applicability of Frequency Domain-Based Fatigue Analysis for Wide Band Gaussian Process I : Rayleigh PDF
정준모(인하대학교); 김경수(인하대학교); 남지명(인하대학교); 구정본(삼성중공업 조선플랜트연구소); 김민수(영국선급협회); 심용래(미국선급협회); 엄항섭(노르웨이선급협회)
49권 4호, 350~358쪽
초록
This paper deals with accuracy of accumulated fatigue damage estimation using stochastic fatigue analysis method based on Rayleigh PDF. From full scale measurement data on an 8100TEU container vessel, zero-order spectral moments for wave- and vibration-induced energy spectral densities are determined on the probability level of 99%. 80 simulation cases in total are prepared according to the variation of ratio of zero-order spectral moments and center frequency of vibration ESD. By using inverse Fourier transformation and rainflow cycle counting for the combined ESD of wave and vibration, exact fatigue damages are derived. Fatigue damages in frequency domain based on Rayleigh PDF show large conservativeness compared to exact fatigue damages in times domain. The main cause of the excessive conservativeness is analyzed by two aspects: ratio of zero crossing and peak frequencies and ratio of initial zero order spectral moments and zero order spectral moments from rainflow stress range distributions. Finally, a guideline of applicability of Rayleigh PDF is proposed for wide band processes.
Abstract
This paper deals with accuracy of accumulated fatigue damage estimation using stochastic fatigue analysis method based on Rayleigh PDF. From full scale measurement data on an 8100TEU container vessel, zero-order spectral moments for wave- and vibration-induced energy spectral densities are determined on the probability level of 99%. 80 simulation cases in total are prepared according to the variation of ratio of zero-order spectral moments and center frequency of vibration ESD. By using inverse Fourier transformation and rainflow cycle counting for the combined ESD of wave and vibration, exact fatigue damages are derived. Fatigue damages in frequency domain based on Rayleigh PDF show large conservativeness compared to exact fatigue damages in times domain. The main cause of the excessive conservativeness is analyzed by two aspects: ratio of zero crossing and peak frequencies and ratio of initial zero order spectral moments and zero order spectral moments from rainflow stress range distributions. Finally, a guideline of applicability of Rayleigh PDF is proposed for wide band processes.
- 발행기관:
- 대한조선학회
- DOI:
- http://dx.doi.org/
- 분류:
- 조선공학