水下爆炸作用下对称结构船体梁整体损伤特性研究

基于相似原则设计了全封闭对称结构船体梁模型,将TNT炸药置于模型中部正下方爆炸,通过改变爆距和药量来研究梁模型在水下近距非接触爆炸作用下的整体损伤特性,比较爆炸气泡运动对梁结构造成的中垂和中拱弯曲损伤作用,探索近距条件下炸药爆炸造成梁发生整体损伤变形时的高效攻击方式。研究发现:在近距非接触爆炸作用下,当爆炸气泡脉动频率与梁一阶湿频率相近时,水下爆炸气泡对梁结构造成的损伤作用以中垂弯曲为主,且爆径比越小,中垂损伤作用越明显;若爆径比不变,随着药量的增大,梁的整体损伤模式会由中垂弯曲向中拱弯曲转变;一定爆距范围内,炸药在远距离多次爆炸比近距离一次爆炸所造成的梁结构中垂损伤变形要大。     

Assessment of port economic impacts on regional economy with a case study on the Port of Lisbon

This article presents a method of assessing the economic impacts of ports at both regional level and national level, through application of input–output analysis. To this end, a methodology for data collection is proposed, which combines a top-down with a bottom-up approach which should help in surpassing some of the difficulties commonly faced in port economic impact studies. The presented methodology allows port planners and policymakers to assess the economic significance and geographic reach of port investments. This study considers the economic impacts of the port cluster and the socio-economic significance of port user industries. The several layers of the analysis are kept separate to allow a better grasp of direct and indirect impacts. The proposed methodology is demonstrated in a study of the Port of Lisbon, which confirms the significance of this port to the Portuguese economy, and also demonstrates that the influence of the Port of Lisbon is mostly limited to an area in close proximity to the port. Therefore, results suggest that investments for the development of logistic infrastructures associated with the port should concentrate in the immediate hinterland of the port.     

洋山四期全自动集装箱码头设计创新

自动化码头在装卸作业的稳定高效、安全节能、绿色环保等方面具有显著优势,已成为我国实现港口转型升级发展的必由之路。但我国自动化港口建设起步晚,技术经验积累少,缺少相应的技术标准和规范指导。而洋山四期工程是我国首座拥有安全自主技术打造的当前全球单项规模最大、技术最先进的全自动化集装箱码头工程,其设计经验对于推动我国港口的技术进步具有重要的借鉴意义。对洋山四期工程自动化集装箱码头设计所涉及的平面、工艺、结构、控制、供电、给排水等多方面设计成果进行总结和梳理,为同类工程设计提供参考。     

不均匀沉降影响下的方块码头胸墙内力有限元分析

针对方块码头普遍存在的不均匀沉降问题,进行不均匀沉降影响下的胸墙内力数值分析。通过有限元软件ANSYS的静力求解模块及接触分析方法,计算得出不均匀沉降影响后在自重及使用期荷载作用下的胸墙内力。结果表明,不均匀沉降影响后的方块码头胸墙内力将显著增加。因此,必须采取一些设计和施工的措施来减小不均匀沉降对方块码头胸墙的影响。     

A review of guidelines for including wider economic impacts in transport appraisal

In this paper we examine how 23 industrialised countries treat wider economic impacts (WEIs) in transport appraisals. We identify 12 different types of impacts based on these countries’ appraisal guidelines. Agglomeration impacts and Production changes in imperfect markets are the most widely accepted, being recognised by 14 and 10 countries, respectively. However, about half of the impacts are mentioned by only one country, and few recommend including the impacts directly in cost–benefit analyses. Several countries provide provisos or criteria that must be met before WEIs can be assessed in the first place. We found method recommendations for quantifying WEIs in 10 countries. However, with the exception of the UK Department for Transport’s (DfT) methodological framework, there is very little international consensus on the choice of appropriate methods. Our findings thus supplement and reinforce the conclusions from the Norwegian Official Report of the Hagen Committee [NOU 2012:16. (2012). Samfunnsøkonomiske analyser. Oslo: Departementenes servicesenter] that there is currently no established consensus on the magnitude and relevance of WEIs, or on how and which of these impacts should be taken into account in transport appraisals. Recommendations for further research and appraisal practices are provided.     

芯层可压缩的夹层梁动态刚度矩阵研究

该文推导了考虑芯层垂向压缩变形影响的夹层梁的动态刚度矩阵,为动态刚度矩阵方法提供了一种新的单元类型。首先给出了一种考虑夹层梁芯层垂向压缩变形影响的夹层梁位移模式,推导了相应的夹层梁动能和势能,根据Hamilton原理推导了其控制微分方程,按动态刚度矩阵的一般推导过程推导了考虑芯层垂向压缩变形影响的夹层梁动态刚度矩阵。计算结果表明文中推导的夹层梁动态刚度矩阵是正确可靠的;在夹层梁的动态刚度矩阵推导和高频振动计算中考虑芯层垂向压缩变形是合理的。     

分裂阵宽带相关检测在圆阵中应用

宽带能量检测作为一种非相关检测方法广泛应用于被动声呐中,但是在复杂环境下其检测性能迅速降低.为了实现分裂阵半波束在圆阵中的应用,本文通过对圆阵的半波束相位差推导和仿真,将分裂阵半波束应用于圆阵的宽带信号检测中,给出一种应用于圆阵的分裂阵宽带相关检测方法.该方法能有效地改善目标方位分辨率,提高被动声呐的宽带检测性能.仿真和试验数据处理结果验证了该方法的有效性,易于工程应用.     

结构分割转换工法结构组合梁可行性研究

为解决结构分割转换工法（CC工法）首个试验项目内部结构设计不经济、施工工序繁琐等问题,文章研究其结构设计优化的可行性。首先介绍CC工法原理,分析该CC工法试验项目施工过程中存在的问题; 然后总结组合梁的构造特点,分析该CC工法试验项目结构设计为组合梁的可行性,并提出相应的关键构造措施; 最后对比试验项目纵梁的理论应力数值与工程实测数值,并分析两者差异的原因。研究结果表明： 1）CC工法的混凝土预制顶板与二次施作的型钢顶纵梁在采取相应的构造措施后,是可协同受力、按组合结构设计的; 2）抗剪连接件、型钢局部稳定性、混凝土翼缘的纵向连接构造措施是CC工法采用组合结构设计的关键点; 3）试验项目的纵梁结构按组合结构考虑时,应根据具体情况对混凝土翼缘的有利作用进行适当折减。     

混凝土简支梁斜截面抗剪强度统一表达式的研究

分析了影响混凝土简支梁抗剪强度的主要因素,优选了主要参数,提出了梁混凝土和箍筋抗剪能力的表达式。通过对专题组试验结果以及国内外８７１片梁的试验数据进行回归和综合分析,提出了混凝土简支梁抗剪强度的统一表达式,现已被采纳为新《铁路桥规》抗剪强度的条文。     

基于VB二次开发的Midas连续梁桥建模技术

结合连续梁桥的结构、施工、受力特点,介绍了使用VB语言开发建立连续梁桥的构造输入、钢束输入以及连续梁桥计算特征值输入的图形界面应用程序,通过应用程序生成Midas的MCT文件,并在Midas中装载MCT文件,以快速、便捷地建立连续梁桥有限元模型。