锁相红外热成像技术应用于复合材料连接接头全场应力测量研究

为了克服传统电测法测量结构应力的种种不足,文章对应用锁相红外热成像技术进行复合材料结构应力测量的可行性进行了研究。在研究中,首先结合正交各向异性复合材料的热弹性理论（TSA）,提出了一种有效而又简洁的试验标定方法,并通过标定试验获取了文中所用玻璃钢材料所需的合理的加载频率f以及标定参数K,然后对两种典型的船用玻璃钢复合材料连接接头内的应力分布进行了测量,通过与数值计算结果的对比,验证了锁相红外热成像技术是一种快速、高效和可靠的结构全场应力测量手段。     

船用复合材料接头全场应力测量方法研究

对应用锁相红外热成像技术测量复合材料结构应力的可行性进行了研究。基于正交各向异性复合材料的热弹性理论(TSA),提出了一种有效和简洁的试验标定方法。通过标定试验获取了玻璃钢材料合理的加载频率f以及热弹性耦合常数CK。对两种典型的船用玻璃钢复合材料连接接头内的应力分布进行了测量,通过与数值计算结果比较,表明锁相红外热成像技术是一种快速、高效、可靠的结构全场应力测量手段。     

复合材料表面加强时冰层的应力应变状态研究（英文）

Ice crossings have been used for several reasons. First, due to the active development of the Arctic shelf, supplies and minerals are provided and transferred on special transports on the surface of ice covers. Second, ice crossings across rivers are used to reduce the length of transport routes. Traditional methods of increasing the load bearing capacity of ice are ice freezing from above, ice freezing from below, and ice strengthening through a wooden copepod flooring. Practical experience shows that the physical and mechanical properties of ice covers are unreliable and changeable in time and strongly depend on various external factors.Therefore, ice covers should be strengthened through alternative methods. Thus, predicting the bearing capacity of ice crossings and exploring methods for their strengthening are important. In this study, we consider the results of experimental and numerical studies on the bearing and deformation capacity of ice beams upon destruction from pure bending. Under pure bending, ice breaks down in the ice crossing when transports move along it. Tests were carried out with a specified reinforcement scheme. The results of the model experiments were compared with numerical calculations in the ANSYS software package. Experiments on ice beams reinforced with various composite materials were also performed. Destruction of samples in all cases occurred as a result of the formation of extensive cracks in the ice caused by the bending moment in the middle of the beam span. Based on the experimental and numerical research results, the use of a surface reinforcement in ice with various materials can increase the bearing capacity from 65% to 99% for this reinforcement scheme.     

基于切口应力强度理论的横向角接焊接接头的疲劳强度评估（英文）

在焊接接头处,由于几何的不连续造成了局部的应力集中,对其疲劳强度评估的研究是十分必要的。文章提出采用奇异强度(as)来计算接头处的几何应力,并基于N-SIF方法分析了不同几何尺寸下十字接头的疲劳强度。结果表明该修正公式可以十分简便地评估出焊接接头处的疲劳强度。     

弯曲载荷下复合材料夹芯“L”型接头强度和疲劳试验研究（英文）

文章研究了复合材料夹芯L型接头在弯曲载荷下的静强度和疲劳问题。通过静加载试验,得到该接头的极限承载能力和破坏模式。在此基础上,对不同载荷水平下的试件进行疲劳试验。基于试验数据建立S-N曲线,比较了半对数线性拟合和S型函数拟合结果。结果表明,S型曲线的预测结果好于半对数线性拟合。同时,分析了疲劳载荷下的接头破坏模式,包括夹芯和面板之间脱粘、面板分层和纤维断裂。根据试验现象划分了表明裂纹扩展的3个阶段。建立了刚度退化模型表现不同载荷水平下刚度退化规律。     

焊接参数对十字型接头焊缝根部和焊趾有效缺口应力的影响（英文）

Cruciform joints in ships are prone to fatigue damage and the determination of type of weld plays a significant role in the fatigue design of the joint.In this paper,the effect of weld geometry on fatigue failure of load carrying cruciform joints in ships is investigated using Effective Notch Stress(ENS) approach.A fictitious notch of 1 mm radius is introduced at the weld root and toe and fatigue stress is evaluated.The effect of weld leg length(l) and weld penetration depth(p) on ENS at weld ro...     

船用螺旋桨叶片应力的数值分析（英文）

In this study, a series of numerical calculations are carried out in ANSYS Workbench based on the unidirectional fluid–solid coupling theory. Using the DTMB 4119 propeller as the research object, a numerical simulation is set up to analyze the open water performance of the propeller, and the equivalent stress distribution of the propeller acting in the flow field and the axial strain of the blade are analyzed. The results show that FLUENT calculations can provide accurate and reliable calculations of the hydrodynamic load for the propeller structure. The maximum equivalent stress was observed in the blade near the hub, and the tip position of the blade had the largest stress. With the increase in speed, the stress and deformation showed a decreasing trend.     

深水球形接头密封的结构设计和性能分析（英文）

To overcome the current difficulties of high-precision machining and the high manufacturing and maintenance costs of spherical seals for deep-water drilling ball joints, a new spherical seal technique is proposed in this paper. The spherical seal is mainly composed of silicone rubber and polytetrafluoroethylene(PTFE). Rational structural design makes the seal independent from the ball and other components, making it easy to replace if leakage occurs at its surface. PTFE can elastically deform over a certain deformation range, which guarantees that two sealing surfaces fit tightly together. O-Ring and PTFE elasticity makes up for any lack of accuracy during spherical machining and decreases the machining precision requirements for spherical surfaces. Using a finite element technique and nonlinear theory, the performance of the spherical seal under the influence of various factors is determined. The results show that the spherical seal designed in this paper exhibits excellent sealing performance under lowtemperature and high-pressure conditions. The spherical seal, a combination of an O-ring and PTFE, has the advantages of cheap manufacturing and maintenance costs and excellent sealing performance.     

一种水运装备制造复合材料性能分析（英文）

In this paper, we investigate the properties of an alternative material for use in marine engineering, namely a rigid and light sandwich-structured composite made of expanded polystyrene and fiberglass. Not only does this material have an improved section modulus, but it is also inexpensive, light, easy to manipulate, and commercially available in various sizes. Using a computer program based on the finite element method, we calculated the hogging and sagging stresses and strains acting on a prismatic boat model composed of this material, and determined the minimum sizes and maximum permissible stresses to avoid deformation. Finally, we calculated the structural weight of the resulting vessel for comparison with another structure of comparable dimensions constructed from the commonly used core material Divinycell.     

水下船舶清洗技术综述（英文）

This paper presents a comprehensive review and analysis of ship hull cleaning technologies. Various cleaning methods and devices applied to dry-dock cleaning and underwater cleaning are introduced in detail, including rotary brushes, high-pressure and cavitation water jet technology, ultrasonic technology, and laser cleaning technology. The application of underwater robot technology in ship cleaning not only frees divers from engaging in heavy work but also creates safe and efficient industrial products. Damage to the underlying coating of the ship caused by the underwater cleaning operation can be minimized by optimizing the working process of the underwater cleaning robot. With regard to the adhesion technology mainly used in underwater robots, an overview of recent developments in permanent magnet and electromagnetic adhesion, negative pressure force adhesion, thrust force adhesion, and biologically inspired adhesion is provided. Through the analysis and comparison of current underwater robot products, this paper predicts that major changes in the application of artificial intelligence and multirobot cooperation, as well as optimization and combination of various technologies in underwater cleaning robots, could be expected to further lead to breakthroughs in developing next-generation robots for underwater cleaning.     

全海深双球连接耐压舱的结构设计探索（英文）

钛合金耐压球壳被广泛地应用于大深度载人潜水器。但是,由于受到材料强度的限制,若采用成熟的Ti-6Al-4VELI来设计3人型的全海深载人舱,其壁厚将超出很多国家的现有制造能力。为了解决这一矛盾,该文提出了一种新的双球连接的方案,并以中国船级社最新的强度标准作为优化约束条件,用有限元分析法对这种结构形式进行了优化设计。最后,对双球结构方案与传统单球方案作了比较。     

LNG船货物操作安全可行技术研究（英文）

In this study, we optimize the loading and discharging operations of the Liquefied Natural Gas(LNG) carrier. First, we identify the required precautions for LNG carrier cargo operations. Next, we prioritize these precautions using the analytic hierarchy process(AHP) and experts' judgments, in order to optimize the operational loading and discharging exercises of the LNG carrier, prevent system failure and human error, and reduce the risk of marine accidents. Thus, the objective of our study is to increase the level of safety during cargo operations.     

基于NSIF的应变能密度法评估焊接接头疲劳强度（英文）

本文介绍了一种基于切口应力强度因子的应变能密度法来评估焊接接头的疲劳强度。该方法将焊接接头简化成尖锐的V型切口。切口尖端应力的奇异性与切口的张开角度有关,切口尖端附近的应力分布可以用切口应力强度因子来描述。切口应力强度因子的计算需要精细的网格划分,在不同的切口张开角度下计算得到的切口应力强度因子之间是无法直接进行比较的。本文基于切口应力强度因子,研究了以R为临界半径的扇形面积内的应变能密度。经验证,应变能密度法不依赖于网格尺寸,包含了焊接接头局部焊接参数等影响,能够准确描述焊趾附近高应力区的应力分布,对于焊接接头疲劳强度的评估具有一定的工程应用价值。     

基于三维测量的无人艇自动靠泊引导方法研究（英文）

Automatic berthing guidance is an important aspect of automated ship technology to obtain the ship-shore position relationship. The current mainstream measurement methods for ship-shore position relationships are based on radar, multisensor fusion, and visual detection technologies. This paper proposes an automated ship berthing guidance method based on three-dimensional(3D) target measurement and compares it with a single-target recognition method using a binocular camera. An improved deep obje...     

杭州湾跨海大桥测量控制技术（一）

本文是对杭州湾大桥在施工建设期测量控制工作的概要总结，介绍了大桥施工建设期主要测量控制关键技术的解决方法及为保证测量控制工作质量所采取的管理措施。     

2015年世界海事技术学术会议（英文）

<正>November 3–7,2015Rhode Island ConventionOmni Hotel Providence,Rhode Island,USA SNAME will host the 5th World Maritime Technology Conference(WMTC)and invites you to submit an abstract for the 2015 Conference.WMTC15 is held under the auspices of the World Maritime Technology Congress,which comprises the world’s most prominent naval architectural and marine engineering professional societies.     

船用玻璃纤维增强复合材料与钢连接结构的力学特性（英文）

The use of a glass-fiber reinforced composite in marine structures is becoming more common, particularly due to the potential weight savings. The mechanical response of the joint between a glass-fiber reinforced polymer(GRP) superstructure and a steel hull formed is examined and subsequently modified to improve performance through a combined program of modeling and testing. A finite-element model is developed to predict the response of the joint. The model takes into account the contact at the interface between different materials, progressive damage, large deformation theory, and a non-linear stress-strain relationship. To predict the progressive failure, the analysis combines Hashin failure criteria and maximum stress failure criteria. The results show stress response has a great influence on the strength and bearing of the joint. The Balsawood-steel interface is proved to be critical to the mechanical behavior of the joint. Good agreement between experimental results and numerical predictions is observed.     

静水压力下纤维缠绕复合材料壳体耐压因子的优化设计（英文）

基于遗传算法和数值分析一体式优化平台,以设计压力因子为目标函数,结构失稳和材料静强度破坏为约束条件,纤维缠绕策略和铺层方式为变量,对静水压力作用下碳/环氧、硼/环氧和玻璃/环氧等三种复合材料壳体的耐压因子进行优化设计。结果表明,复合材料耐压壳体在深海环境下能够提供充足的正浮力;对于不同的复合材料,最大设计压力受限的因素有所不同,主要受限于结构失稳或材料强度破坏;纤维缠绕策略和铺层方式对设计压力因子具有显著影响。文中最后提出变厚度设计、复合材料肋骨等增强方式,旨在解决结构失稳或材料强度破坏对最大设计压力的限制,研究成果可为复合材料耐压壳体结构设计提供参考。     

基于切口应力强度理论的135°拐角处应力场分析（英文）

在焊接接头处,几何的不连续造成了局部的应力集中,形成了应力奇异效应,有必要做进一步的研究。文章基于切口应力强度理论,引入了奇异强度as的概念,提出了评估切口应力的简便算法,并通过一系列十字形模型进行了验证。最后,将修改表达式的预估结果同N-SIF公式作了对比分析,结果表明该修正公式可以简单、准确地预估焊接接头处的应力。     

2018离岸技术大会(OTC)（英文）

<正>30 April–3 May 2018 in Houston,Texas,USA Since its inception in 1969,OTC has provided a forum to present cutting-edge technologies and innovations which have shaped the entire industry and led the way to many dramatic achievements.As the 50th OTC approaches,we have an opportunity to help prepare for a sustainable future.The program committee encourages submissions which will align with the