Development of Empirical Formulas for Approximate Spectral Moment Based on Rain-Flow Counting Stress-Range Distribution
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초록
Many studies have been performed to predict a reliable and accurate stress-range distribution and fatigue damage regarding the Gaussian wide-band stress response due to multi-peak waves and multiple dynamic loads. So far, most of the approximation models provide slightly inaccurate results in comparison with the rain-flow counting method as an exact solution. A step-by-step study was carried out to develop new approximate spectral moments that are close to the rain-flow counting moment, which can be used for the development of a fatigue damage model. Using the special parameters and bandwidth parameters, four kinds of parameter-based combinations were constructed and estimated using the R-squared values from regression analysis. Based on the results, four candidate empirical formulas were determined and compared with the rain-flow counting moment, probability density function, and root mean square (RMS) value for relative distance. The new approximate spectral moments were finally decided through comparison studies of eight response spectra. The new spectral moments presented in this study could play an important role in improving the accuracy of fatigue damage model development. The present study shows that the new approximate moment is a very important variable for the enhancement of Gaussian wide-band fatigue damage assessment.
Abstract
Many studies have been performed to predict a reliable and accurate stress-range distribution and fatigue damage regarding the Gaussian wide-band stress response due to multi-peak waves and multiple dynamic loads. So far, most of the approximation models provide slightly inaccurate results in comparison with the rain-flow counting method as an exact solution. A step-by-step study was carried out to develop new approximate spectral moments that are close to the rain-flow counting moment, which can be used for the development of a fatigue damage model. Using the special parameters and bandwidth parameters, four kinds of parameter-based combinations were constructed and estimated using the R-squared values from regression analysis. Based on the results, four candidate empirical formulas were determined and compared with the rain-flow counting moment, probability density function, and root mean square (RMS) value for relative distance. The new approximate spectral moments were finally decided through comparison studies of eight response spectra. The new spectral moments presented in this study could play an important role in improving the accuracy of fatigue damage model development. The present study shows that the new approximate moment is a very important variable for the enhancement of Gaussian wide-band fatigue damage assessment.
참고문헌 (17)
- Standard Practices for Cycle Counting in Fatigue Analysis, "American Society for Testing and Materials", ~, pp.ASTM E1049-85 (2005)
- Benasciutti, D., "Fatigue Analysis of Random Loadings", PhD, pp.2004
- D. Benasciutti, "Analogies between spectral methods and multiaxial criteria in fatigue damage evaluation", Probabilistic Engineering Mechanics, 31, pp.39~45 (2013), Elsevier BV[DOI]
- Recommended Practice for Riser Fatigue, "Det Norske Veritas", DNV, ~, pp.DNV-RP-F204 (2010)
- Dirlik, T., "Application of Computers in Fatigue", PhD, pp.1985
- Shan Gao, "An improved spectral discretization method for fatigue damage assessment of bimodal Gaussian processes", International Journal of Fatigue, 119, pp.268~280 (2019), Elsevier BV[DOI]
- G. Jiao, "Probabilistic analysis of fatigue due to Gaussian load processes", Probabilistic Engineering Mechanics, 5(2), pp.76~83 (1990), Elsevier BV[DOI]
- Seock-Hee Jun, "Development of a novel fatigue damage model for Gaussian wide band stress responses using numerical approximation methods", International Journal of Naval Architecture and Ocean Engineering, 12, pp.755~767 (2020), 대한조선학회[DOI]
- Curtis E. Larsen, "Predicting the Fatigue Life of Offshore Structures by the Single-Moment Spectral Method", Stochastic Structural Dynamics 2, 2, pp.91~120 (1991), Springer Berlin Heidelberg[DOI]
- Fatigue Assessment Including Hull Girder Springing. Global Design Loads of Container Ships and Other Ships Prone to Whipping and Springing, "Lloyd’s Register", 45~51 (2018)
- Loren D. Lutes, "Improved Spectral Method for Variable Amplitude Fatigue Prediction", Journal of Structural Engineering, 116(4), pp.1149~1164 (1990), American Society of Civil Engineers (ASCE)[DOI]
- Jun-Bum Park, "A new fatigue prediction model for marine structures subject to wide band stress process", Ocean Engineering, 76, pp.144~151 (2014), Elsevier BV[DOI]
- I RYCHLIK, "A new definition of the rainflow cycle counting method", International Journal of Fatigue, 9(2), pp.119~121 (1987), Elsevier BV[DOI]
- Erik H. Vanmarcke, "Properties of Spectral Moments with Applications to Random Vibration", Journal of the Engineering Mechanics Division, 98(2), pp.425~446 (1972), American Society of Civil Engineers (ASCE)[DOI]
- Paul H. Wirsching, "Fatigue under Wide Band Random Stresses", Journal of the Structural Division, 106(7), pp.1593~1607 (1980), American Society of Civil Engineers (ASCE)[DOI]
- W ZHAO, "On the probability density function of rainflow stress range for stationary Gaussian processes", International Journal of Fatigue, 14(2), pp.121~135 (1992), Elsevier BV[DOI]
- X.Y. Zheng, "Cross-mode couplings for the fatigue damage evaluation of trimodal Gaussian processes", Ocean Engineering, 202, pp.107177~ (2020), Elsevier BV[DOI]