Tang W.-Y.,Shanghai JiaoTong University |
Zhang D.-K.,Technology Research and Development Center
Chuan Bo Li Xue/Journal of Ship Mechanics | Year: 2013
Risk acceptance criterion is an important component of risk evaluation. The selection of risk acceptance criteria will influence the estimation of risk level directly. In this paper, a FPSO is illustrated to calculate the probability of failure of component thickness and time-variant reliability of ultimate strength of hull girder. Based on obtained results under different corrosion conditions, reasonable risk acceptance criteria are chosen regarding performance of overall structure and component in order to reflect risk level of FPSO roundly. Finally, initial layout of inspection and maintenance is discussed based on chosen risk acceptance criteria.
Zheng M.-H.,Technology Research and Development Center
Yejin Fenxi/Metallurgical Analysis | Year: 2015
In production of aluminum alloy, the addition of grain refiner can not only adjust the content of some elements in the alloy but also refine the grains. In order to accurately determine the impurity elements, a method for the determination of aluminum, iron and manganese in the grain refiner (titanium agent and titanium boron agent) was discussed by inductively coupled plasma atomic emission spectrometry (ICP-AES) with standard addition method. The sample was dissolved in sulphuric acid (1+1) and in the solution different amounts of aluminum, iron, manganese standard solution were added, it was then determined with the standard addition method software built in the ICP spectrometer. Through condition tests, it was determined that sulfuric acid (1+1) was adopted to dissolve samples and the spectral lines of 369.153 nm, 259.940 nm and 257.610 nm were selected as analytical lines of Al, Fe and Mn. Al, Fe and Mn in the grain refiner used in aluminum industry were determined under selected experimental conditions, so that the effect of large amounts of titanium matrix as well as high concentration sulfuric acid and spectral interference could be avoided effectively. The linear correlation coefficient (r) of the calibration curve was higher than 0.999 9. The proposed method has been applied to determine Al, Fe and Mn in titanium agent and titanium boron agent, whose results were consistent with those of other methods with relative standard deviation (RSD) less than 1.6% (n=10). ©, 2015, Central Iron and Steel Research Institute. All right reserved.
Feng G.,Harbin Engineering University |
Hu B.,Harbin Engineering University |
Wu M.,Technology Research and Development Center |
Ren H.,Harbin Engineering University
Huazhong Keji Daxue Xuebao (Ziran Kexue Ban)/Journal of Huazhong University of Science and Technology (Natural Science Edition) | Year: 2015
Considering the random property of the corrosion of ship structures, the method for the ultimate strength analysis of ship plate structure subjected to random corrosion degradation was presented. According to the measured corrosion data of bulk carriers, the distribution of the corrosion data for midship deck plate were analysed and the random corrosion model was established. The ultimate strength of the corroded deck plate was calculated by applying the nonlinear finite element analysis. The statistical descriptions of the ultimate strength of the corroded deck plate were defined through Monte Carlo simulations. The reliability analysis of the ultimate strength of the corroded deck plate was performed. It shows that both the corrosion data of the deck plate and the ultimate strength of the random corroded deck plate are in line with the log-normal distribution. The ultimate stress ratio is inversely proportional to the corrosion volume ratio. © 2015, Editorial Board of Journal of Huazhong University of Science and Technology. All right reserved.