AB组填料在高铁路基填筑施工中的质量控制与检测

本文主要介绍哈尔滨至大连客运专线路基AB组填料施工工艺。     

Numerical simulations of fatigue crack initiation and propagation based on re-tensile plastic zone generating load criterion for in-plane gusset welded joints

Many accidents are caused by fatigue in welded built-up steel structures, and so it is important to estimate the fatigue lives of such structures quantitatively for safety reasons. By assuming that fatigue cracks cannot grow without an accumulation of alternating tensile/compressional plastic strain, one of the authors identified an improved effective stress intensity factor range ΔK _RPG based on the re-tensile plastic zone generating (RPG) load, which represents the driving force for fatigue cracks, and suggested that ΔK _RPG should be used as the parameter to describe fatigue crack growth behavior. The “FLARP” numerical simulation code in which ΔK _RPG is implemented as the fatigue crack growth parameter, was developed in order to predict fatigue crack initiation and propagation behavior. In this paper, it is demonstrated that FLARP gives accurate estimates for fatigue life by comparing the estimated fatigue crack growth curves and S–N curves with the experimental results for in-plane gusset welded joints, which are used in many welded steel structures. Moreover, the effect of induced bending moment due to the linear misalignment in the out of plane direction on the fatigue strength of in-plane gusset welded joints is investigated through numerical simulations.     

水下爆炸作用下箱形梁模型响应试验研究

对模拟水面舰船结构的箱形梁模型在水下爆炸作用下的响应进行试验,借助高速摄像机观测气泡脉动过程和结构响应过程,发现箱形梁结构在水下爆炸作用下的响应可以分为三个阶段.不同的爆点位置,气泡脉动能够激起不同振动形式的鞭状响应运动.     

Workspace analysis to generate a collision-free torch path for a ship welding robot

We propose a method to determine the optimal initial location and to generate torch paths for a ship welding robot with 6 degrees of freedom (DOF). The optimal initial location is determined using an objective function, which is set up by combining constraints on the torch posture, manipulability, and the range of each joint angle to avoid collisions. A genetic algorithm (GA) is used to optimize the objective function because it does not require additional derivatives. After the initial location is determined, torch paths are generated by interpolating the starting point, endpoints and torch postures using inverse kinematics. Our method can be applied to automate the welding job for each block during ship building, irrespective of the shape of the robots, by changing the objective function.     

气泡艉流场特征及其研究综述

船舶气泡艉流场特征研究蕴含着重要的军事和民用价值.从气泡艉流场的几何特征、声光物理特征以及尾流中气泡的数密度、尺度分布特征等方面,总结了当前国内外关于船舶气泡艉流场特征研究的主要成果,进而通过分析它们在遥感探测、制导等领域的应用情况,进一步阐明了船舶气泡艉流场特征研究的重要性,并提出了应加强对气泡艉流场的探测技术和抑制消除技术研究的发展建议.     

海上溢油收集装置概念设计

随着海洋石油开采和运输事业的日益发展,海上溢油问题的研究越来越受到重视,具有重要的理论价值和实际意义.论文针对各类海上溢油事故,在现有技术的基础上进行突破和创新,提出了三套新概念的海上溢油处理装置,热气球海上浮油收集装置、海上铲车浮油收集器和下潜式浮油收集器,分别利用漩涡原理,面面接触的物理方式和生物环保技术,有效提高海上溢油的收集效率,丰富了溢油处理装置的设计理念,为后续的详细设计奠定了基础.     

船舶辅机直流调速系统失磁故障的分析及研究

分析了船舶辅机直流晶闸管调速系统各种控制方案失磁的原因,提出了解决失磁问题的方法,设计出了相关的检测电路,并给出了电路参数及调试时应注意的问题.     

港口门机司机绩效考核系统设计

针对某港口企业下属门机队现行绩效考核和管理相对落后的状况提出了有效的改进策略。基于门机作业实时记录,采用Microsoft SQL2005数据库、VC＋＋6．0和水晶报表技术设计了一套司机作业绩效考核软件,实现了对现场采集数据的转换和存储,并结合作业票数据考核门机司机的作业量,自动生成每月的机械队员工工资报表,同时,港口企业通过司机绩效考核软件完成对生产数据的科学、有效的管理。     

长撑杆双颚板绳索抓斗自重的确定及其在抓斗各部件上的分配比例

主要阐述抓斗的主要参数之一——抓斗自重及其在抓斗各部件上的分配比例对抓斗性能的影响;抓斗抓取量与抓斗自重、散货物理-力学性质之间的关系,提出了如何合理确定抓斗自重及其在抓斗部件上的分配比例的方法。     

挖泥船产量计密度测量精度分析及放射源核素、活度选择研究

通过理论分析结合长江武汉航道工程局挖泥船施工现场情况提出以清水计数率作为密度测量精度的评价指标,在此基础上推导出针对不同排泥管径所需放射源活度的计算公式,据此结合现场条件建立放射源核素及活度的选择条件,为提高设备的有效性提供依据。