CATIA二次开发在船舶建模与评估中的应用

为提高CATIA在船舶建模评估应用中的效率与精度,使用VB编程语言对CATIA进行二次开发,建立界面,不仅可方便地输入舵参数,快速创建舵和舵踵曲面,而且可设定吃水高度、海水密度、船壳厚度等,以统计主尺度、船形系数和尺度比等多种船体主要要素并自动导出,大幅提高多方案建模与评估的工作效率。给出程序思想和关键程序代码,对相关软件开发具有参考作用。     

干线公路全深式冷再生混合料配合比设计

对干线公路路网改造中常用的全深式冷再生方式进行了阐述,对旧沥青路面材料的性能进行了分析,通过试验手段取得了再生混合料的配合比设计。试验证明,添加20％新骨料和5％水泥后再生料的各项指标完全能够满足规范中路用基层的要求。     

长江干线航道信息需求分析

通过对航运、港口单位,水上交通安全的管理机构、航道管理机构、引航机构、研究机构等的调研,并对有关专家、管理及技术人员进行现场咨询和问卷调查经分析,提出了航运业对长江干线航道信息的基本需求。     

基于滑移网格法桨——舵相互干扰流场分析

采用CFD方法,利用滑移网格法,以JDC4-55可调螺距螺旋桨与非对称舵为考核算例,模拟桨—舵相互干扰引起的三维非定常湍流,通过改变舵角来得到相应的流场,分析在同一进速系数下流场变化规律,从模拟的结果来看,该方法能较好地展示桨舵干扰的粘性流场。     

船体高效舵系统舵结构强度计算方法研究

在船舶高效舵系统中,采用舵杆和套筒对舵叶进行固定和旋转。该系统结构设计的关键是合理的舵杆和套筒结构,目前还没有专门的设计指导方法,为此发展了船体高效舵系统舵杆和套筒结构强度的直接计算评估方法,它可以较准确地预报舵杆和套筒的应力和变形。对一个高效舵系统设计方案进行了计算,开展了套筒厚度优化计算分析,研究套筒壁厚对舵系统各构件的应力和变形的影响,用以指导相关船舶高效舵系统的结构设计。     

“高速快船”舵杆修理工艺研究

文章介绍了"高速快船"舵系修理过程中,针对该船舵杆连接法兰处存在严重贯穿裂缝、舵杆几近报废的情况下,相关人员与船东、船检一起,制定合理的焊接工艺方案,做好焊接工艺评定得到BV认可,并严格按照工艺施工,最终完成了舵杆的修复。在舵杆焊接修理"禁区"上前进了一步。     

Expertise in decision-making for large infrastructure projects: from UK trunk roads to High Speed Rail 2

At the decision-making stage, a large-scale infrastructure project is essentially a broad concept, and this means the expert analyses will differ from each other and become contested over time, leading to the emergence of rival narratives. It is only where there is a limited range of expert analyses that the bases for decision-making will remain relatively clear-cut. Over time the contested nature of expertise can significantly inhibit the construction of effective narratives, either for or against the project, and also make decision-making more complex and problematic. Decision makers may also seek greater clarification through the construction of narratives that rise above these disputed areas of expertise, and the scientific evidence becomes less important. This paper examines the changing nature of contested expertise through a comparative analysis of political decision-making between UK trunk roads policy and the case of High Speed Rail 2, through the framework of epistemic communities.     

A study on improving the course-keeping ability of a pure car carrier in windy conditions

The course-keeping ability of a pure car carrier (PCC) in windy conditions is discussed in this article. Numerical simulations of two PCCs were carried out to compare their course-keeping abilities in wind. The two PCCs had the same hull form but different types of rudder. One PCC was fitted with a semispade rudder (hereinafter, the normal rudder), whereas the other was fitted with a spade-type Schilling rudder (hereinafter, the Schilling rudder). Both PCCs were designed to a new concept for the accommodation structure and hull form above the load water line. In this new design concept, there are no sharp corners in the superstructure so as to reduce wind resistance and improve steering performance. The limits of course keeping for the two PCCs were investigated through simulations. The course-keeping abilities of the two PCCs, each with two different types of autopilot system, were also investigated in wind. To develop the numerical simulation, the hydrodynamic coefficients of the two PCCs were predicted based on the data published for a third PCC having similar principal particulars. The numerical model of the two PCCs was validated by comparing its behavior with the respective full-scale trial results. Wind resistance coefficients were predicted by combining the results of wind tunnel experiments of the object PCCs and a regression model. Numerical simulations under steady wind conditions were also carried out and the results compared with some full-scale experiments to validate the mathematical model of the PCC.     

不对称信息理论在船舶运动控制中的应用

本文介绍了不对称信息理论，并针对舵阻摇控制系统，通过简化鲁棒控制算法和改进舵机执行机构性能，增加信息的传递量，在提高系统鲁棒性能的基础上，使该算法成为实际工程上可用的算法。闭环增益成形算法采用闭环系统中具有工程意义的参数直接构造出鲁棒控制器，其设计过程简单，且物理意义明晰。从仿真结果可以看出：当信息传递充分时，航向保持效果大大改善，打舵的频率和幅值明显降低，同时也较为节能。     

工业工程方法在电力机车线槽布线中的应用

采用工业工程、人因工程等方法,分析了电力机车中央线槽预布线的作业顺序、作业时间、移动距离、作业区域布置与员工移动路径等问题,对中央线槽预布线的工艺流程、工艺方法进行了优化。研究结果可以为提高员工作业效率和改善员工作业环境的技术改造与提升提供参考。