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This paper presents a simplified method for the reliability- and the integrity-based optimal design of engineering systems and its application to offshore mooring systems. The design of structural systems is transitioning from the conventional methods, which are based on factors of safety, to more advanced methods, which require calculation of the failure probability of the designed system for each project. Using factors of safety to account for the uncertainties in the capacity (strength) or demands can lead to systems with different reliabilities. This is because the number and arrangement of components in each system and the correlation of their responses could be different, which could affect the system reliability. The generic factors of safety that are specified at the component level do not account for such differences. Still, using factors of safety, as a measure of system safety, is preferred by many engineers because of the simplicity in their application. The aim of this paper is to provide a simplified method for design of engineering systems that directly involves the system annual failure probability as a measure of system safety, concerning system strength limit state. In this method, using results of conventional deterministic analysis, the optimality factors for an integrity-based optimal design are used instead of generic safety factors to assure the system safety. The optimality factors, which estimate the necessary change in average component capacities, are computed especially for each component and a target system annual probability of system failure using regression models that estimate the effect of short and long term extreme events on structural response. Because in practice, it is convenient to use the return period as a measure to quantify the likelihood of extreme events, the regression model in this paper is a relationship between the component demands and the annual probability density function corresponding to every return period. This method accounts for the uncertainties in the environmental loads and structural capacities, and identifies the target mean capacity of each component for maximizing its integrity and meeting the reliability requirement. In addition, because various failure modes in a structural system can lead to different consequences (including damage costs), a method is introduced to compute optimality factors for designated failure modes. By calculating the probability of system failure, this method can be used for risk-based decision-making that considers the failure costs and consequences. The proposed method can also be used on existing structures to identify the riskiest components as part of inspection and improvement planning. The proposed method is discussed and illustrated considering offshore mooring systems. However, the method is general and applicable also to other engineering systems. In the case study of this paper, the method is first used to quantify the reliability of a mooring system, then this design is revised to meet the DNV recommended annual probability of failure and for maximizing system integrity as well as for a designated failure mode in which the anchor chains are the first components to fail in the system. 相似文献
633.
基于GIS电子江(海)图与信息系统的内河模拟引航研究 总被引:2,自引:0,他引:2
应用地理信息系统(GIS)方法,在讨论电子海图与电子江图异同的基础上,对电子江图数据库结构进行了设计,并阐述了电子江图与信息系统实现的功能。文章分析了内河船舶运动数学模型和解算方法,提出了内可模拟引航要求实现的主要功能,并用计算机软件加以实现。 相似文献
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近年来我国挖泥船技术有了较大的发展,挖泥船市场需求也日益增长,但国内挖泥船的作业控制系统技术还比较落后,严重制约挖泥船在作业中设备的效能发挥,为提高挖泥船控制系统性能及作业整体效率,本文引入分布式开放网络架构设计挖泥船控制系统的三层网络结构,提高系统通信实时性,可靠性和抗干扰能力.对与上位机系统,采用OPC模式设计web上位机软件系统,实现系统的便捷操作,提高系统的维护和管理质量,降低维护成本. 相似文献
637.
�й����ܽ�ͨ��չս���о���˼·������̽�� 总被引:6,自引:2,他引:6
中国的交通面临着前所未有的挑战和机遇,本文在分析我国交通运输系统存在问题的基础上,探讨了我国智能交通发展战略研究的必要性和迫切性,并运用系统分析方法,分析了我国智能交通发展战略研究的思路和技术路线,提出了在研究智能交通发展战略中需要解决的关键问题,包括交通与社会经济发展的关系、国内外ITS发展情况、各种运输方式发展战略等。 相似文献
638.
智能交通系统中的交通信息采集技术研究进展 总被引:2,自引:1,他引:2
实时、准确的交通信息采集是智能交通的基础。根据被采集车辆是否与采集系统进行交互,交通信息采集技术分为两大类:独立式采集技术和协作式采集技术。分析了各种采集技术的特点、适用场合和发展现状,并提出了未来的发展趋势:车辆内部信息的直接获取、交换式信息采集、多种采集技术的融合。 相似文献
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当前,人们在平时出行的时候,不只是选择火车或者高铁,也会选择客运的方式,尤其是对于中途或者是短途而言,汽车的灵活性特征十分明显。然而,汽车在长时间运转的时候,可能会出现某些故障方面的问题,尤其是电气系统领域的故障,此类故障会对汽车性能起到很大程度上的影响,导致这样的故障对人员伤害起到严重影响。所以在对汽车进行实际维修的时候,需要关注电气系统故障问题,将先进的方式方法运用其中,做好诊断维修工作。只有这样,才可以保障其诊断质量和维修水平。基于此,文章就汽车电气系统故障的诊断维修技术展开了全面深入的探究分析,以此为将来的有关研究提供相应的参考。 相似文献