排序方式： 共有45条查询结果，搜索用时 15 毫秒
41.
Premkumar Thodi Faisal Khan Mahmoud Haddara 《Stochastic Environmental Research and Risk Assessment (SERRA)》2009,23(6):793-809
The deterioration of the condition of process plants assets has a major negative impact on the safety of its operation. Risk
based integrity modeling provides a methodology to quantify the risks posed by an aging asset. This provides a means for the
protection of human life, financial investment and the environmental damage from the consequences of its failures. This methodology
is based on modeling the uncertainty in material degradations using probability distributions, known as priors. Using Bayes
theorem, one may improve the prior distribution to obtain a posterior distribution using actual inspection data. Although
the choice of priors is often subjective, a rational consensus can be achieved by judgmental studies and analyzing the generic
data from the same or similar installations. The first part of this paper presents a framework for a risk based integrity
modeling. This includes a methodology to select the prior distributions for the various types of corrosion degradation mechanisms,
namely, the uniform, localized and erosion corrosion. Several statistical tests were conducted based on the data extracted
from the literature to check which of the prior distributions follows data the best. Once the underlying distribution has
been confirmed, one can estimate the parameters of the distributions. In the second part, the selected priors are tested and
validated using actual plant inspection data obtained from existing assets in operation. It is found that uniform corrosion
can be best described using 3P-Weibull and 3P-Lognormal distributions. Localized corrosion can be best described using Type1
extreme value and 3P-Weibull, while erosion corrosion can best be described using the 3P-Weibull, Type1 extreme value, or
3P-Lognormal distributions. 相似文献
42.
张兰英 《广东海洋大学学报》1995,(2)
高铝锌基合金是７０年代发展起来的一类新型合金。运用材料科学理论综合分析了国内外专家和研究人员在高铝锌基合金的组织、凝固特点与铸造性能、机械性能、耐蚀性能、热强性方面的研究现状．指出了存在的问题，提出了几点建议。 相似文献
43.
Laurent Désindes Laurent Bailly Jacques Leroy Marc Lespinasse 《Comptes Rendus Geoscience》2005,337(9):832-840
The comparative study of two French high-purity silica placers of European class suitable for the electrometallurgy of silicon and ferrosilicon, located at Boudeau and Thédirac, in the Dordogne and Lot departments respectively, indicates strong similarities as regards the sources and the transportation of quartz, as well as a same process of undercover karstification as a determining factor in the formation of the deposits. The main difference lies in the number of the stages necessary to the formation of the trap. This comparative study allows the constitution of dynamic models for the genesis of these economic quartz concentrations. To cite this article: L. Désindes et al., C. R. Geoscience 337 (2005). 相似文献
44.
在市政管道建设中,检查井主要作用是方便地下管线清淤、疏通以及修复等维护工作。检查井不仅承担路面车辆活荷载,还承担外部周围土体的土压力以及地下静水压力,井壁内部环境也十分复杂,长期受到废液和废气的腐蚀,十分容易出现破坏。针对这一情况,有必要对检查井及时地进行修复,防止其进一步恶化。保证检查井的密封性以及结构完整性。检查井的修复方法包括预制检查井更换,原位浇筑混凝土内衬,原位固化衬里,砂浆喷涂,黄麻纤维加聚氨酯树脂预聚物以及速凝水泥修复技术,各方法的设计施工特点以及适用范围有所不同。 相似文献
45.
采用有限元软件ABAQUS,以锈蚀率（0%、5%、10%、15%和20%）为变量,对5根钢筋混凝土柱的力学性能进行了数值模拟,研究各试件的滞回性能、骨架曲线、延性及耗能能力,分析钢筋锈蚀率对承载力、延性、耗能和塑性铰转动能力的影响。研究结果表明:模拟分析得到的锈蚀钢筋混凝土柱的强度和变形与试验结果吻合较好,建立的有限元模型可用于锈蚀钢筋混凝土柱的力学性能分析;混凝土开裂前,锈蚀构件的力学性能基本与未锈蚀构件相同,混凝土开裂后,构件的承载力、屈服荷载、极限位移、延性等均随钢筋锈蚀率的增大而降低;轻度锈蚀构件的滞回性能和破坏形式与未锈蚀构件类似,随着钢筋锈蚀率逐渐增大,滞回环的饱满程度降低,“捏拢”现象严重,滞回曲线由“弓形”逐渐发展成“反S形”,耗能能力降低,破坏形式趋于脆性破坏,位移延性系数、平均耗能系数等指标逐渐下降。 相似文献