Finite element damage analysis of an underwater glider–ship collision

Underwater gliders, which are profiling autonomous underwater vehicles designed to make oceanographic measurements, are increasingly used in the coastal ocean. As they regularly surface for data transmission, gliders increasingly pose a risk for fast ships. In order to estimate the extent of damage due to collision, 3D finite element simulations of collisions between a glider and a high-speed craft with a glass-fiber reinforced plastic hull are performed. Different collision scenarios such as impact locations, angles of attack and speeds are examined. The results are compared to an analytical solution based on simplifying assumptions. Although both methods reveal consistent results, it is shown that finite element simulations are required to account for the 3D shape of the ship. The results indicate that at ship velocities exceeding 7.5 m/s (14.6 kt) the glider penetrates the ship’s hull causing severe damage to its structure.     

Model course to revalidate deck officers’ competences using simulators

In accordance with Part A, Chapter I, Section I/11 Revalidation of Certificates of the Standards of Training, Certification and Watchkeeping for Seafarers (STCW) 2010 Convention, continued evaluation of professional competence shall be established, among others, by successfully completing an approved training course or courses. Every master, officer and radio operator holding a certificate issued or recognised under any chapter of the convention other than chapter VI, who is serving at sea or intends to return to sea after a period ashore, shall be required, at intervals not exceeding 5 years, to demonstrate continued professional competence, in order to continue to qualify for seagoing service. The main objective of this research is to design a model course using simulation technology to train and demonstrate seafarers’ competence in accordance with the provisions of STCW Code for existing seafarers who need to revalidate their professional maritime certificates also in accordance with the standards governing the use of simulators, Reg I/12 of 2010 STCW Code. The purpose of this revalidation simulation-based model course is to assist maritime training institutes and their teaching staff in organising and introducing specific training courses for revalidation of certificates of competence (CoCs) as well as enhancing, updating or supplementing existing training material where the quality and effectiveness of the training courses may thereby be improved. Only those STCW competences relating to ship bridge simulators will be considered for the model course scenario development and testing.     

半刚性基层沥青路面反射裂缝成因

介绍半刚性基层沥青路面反射裂缝的形成机理,综述半刚性基层沥青路面反射裂缝与各影响因素间的变化规律。影响反射裂缝的因素可分为路面结构材料特性、路面结构温度场特性、路面结构荷载特性、路面结构层之间结合状态和反射裂缝长度等。     

客土喷播绿化技术在石质边坡防护中的应用

以长珲公路采用客土喷播技术对石质边坡绿化为例,介绍施工方案,发挥植物的生态防护及视觉诱导作用,符合"安全、舒适、环保、和谐"的建设要求,可供今后工程建设中参考。     

俄罗斯中部地区在国际运输走廊发展中的角色

许多理论研究以及实践结果表明,中部地区的地理位置可以在全球经济市场和一体化的运输体系中成为该地区的主要竞争优势,认识不足或忽视空间地域因素在经济发展中起到的作用,将导致在管理决策上作出错误的判断.本文研究乌拉尔联邦区作为俄罗斯联邦中部地区在国际运输走廊发展中的角色.     

城市公交系统规划方案的综合评价

在考虑影响城市公交系统方案优选的多种因素的基础上,构建了城市公交系统方案优选的指标体系.利用模糊物元理论,建立了公交系统方案优选评判模型.引入熵理论确定各指标的权重,通过计算各模糊物元与标准模糊物元之间的欧式贴近度值,对各方案进行优劣排序,从而得到最优方案,并结合实例进行应用.通过与模糊综合评判法比较,进一步验证了该模型的合理、简便和实用.     

公路施工准备阶段的测量工作探讨

近年来,公路建设快速向前发展.然而在我国山区高等级公路施工过程中,准备阶段的测量工作存在着种种不合理的现象,延误工程项目的施工进度,造成不必要的经济损失.对公路工程项目施工准备阶段的测量工作进行探讨,可为同类工程提供一定的参考.     

水泥混凝土路面常见病害与施工工艺的关系

随着交通事业的快速发展,水泥混凝土路面修筑数量越来越多。然而,已修建的水泥混凝土路面早期出现的啃边、缺角、断板、错台等病害,严重影响到了水泥混凝土路面的使用寿命和道路行车质量,给国家的投资造成了很大浪费。因此,必须研究预防和治理这些病害的施工工艺。     

公路桥梁设计中的安全性和耐久性探讨

公路桥梁的安全性和耐久性,是确保整个工程质量的重要因素,已成为公路桥梁设计中的关键控制点.对公路桥梁设计中出现安全性和耐久性问题的原因进行分析,并有针对性地提出设计策略,对于公路桥梁投入使用后满足安全性、稳定性要求具有重要意义.     

粗集料性能对骨架密实性沥青混合料的影响(英文)

沥青玛蹄脂碎石混合料(SMA)成功并且有效地应用于多国路面面层。针对纳黔高速公路,采用当地集料设计SMA。通过两种粗集料(石灰岩、玄武岩)的不同配比作为分析对象,测试(马歇尔稳定度、动稳定度、低温弯曲试验、构造深度、摩擦系数)得到沥青SMA体积参数和性能指标。分析得出的SMA是符合工程需要的优质面层材料,具有良好的抗滑能力,低温抗裂性能和良好的耐久性。结果表明:不同的集料配合比显著地改变了SMA混合料的性能。