关于重载铁路货车缓冲器技术的研究

通过对国内外重载货车缓冲器的发展趋势和存在问题的分析,结合大秦线重载列车运输试验结果的研究,对我国重载货车缓冲器的主要性能参数的选取、试验及评定方法提出了建议。     

B0B0B0机车粘着性能的理论研究 （上）

本文对几种不同牵引装置的B_0B_0B_0机车在牵引工况中的轴重转移进行计算分析,从而推导出其设计参数的相关函数式和机车最佳粘着性能的参数匹配方法。此外,还论述改善B_0B_0B_0机车动态粘着性能的设计措施,并进行实例论析。     

齿轮修形在机车上的应用

提出了单侧直齿传动大功率电力机车牵引齿轮的齿向螺旋形就形修正、齿端修薄和齿枯、齿根修缘的计算以及设计方法，运用方法成功地研制的ＳＳ７型电力机车的牵引齿轮，结束了我国大功率电力机车有用双侧斜齿轮传的历史。     

Application of analytical model in the prediction of dynamic responses and fatigue damage of flexible risers: Part II – Dynamic analysis of flexible risers in large-scale domain using a direct moment correction method

In recent years, the dynamic responses of flexible risers have been the focus of many researchers. Most flexible risers undergo a substantial level of irregular motion from environmental loadings, which involves a continuous slip of helical wires. The slip of helical wires especially leads to a hysteretic effect by reducing the bending stiffness, making it hard to predict the dynamic responses of flexible risers. The current study, as an extension to Part I, presents a new large-scale dynamic analysis method for flexible risers. The suggested method creates a large-scale model for the dynamic analysis that considers a geometric and bending nonlinearity of flexible risers. The kinematics of each beam element is formulated based on a Green-Lagrangian strain and the interaction with the seabed, providing a realistic analysis of flexible risers. In particular, the current study introduces a direct moment correction method that modifies the internal force vector using an improved analytical model. The improved analytical model is assigned at each node of the large-scale model and estimates an accurate bending hysteresis curve considering the effect of shear deformation and varying tension. The suggested method corrects the bending moment and shear force of all beam elements based on the bending hysteresis curves obtained from the improved analytical model, by which a complex bending behavior of flexible risers is reflected in a large-scale domain. As a result, this study achieves a more accurate prediction of the dynamic responses and fatigue damage of flexible risers. A new dynamic analysis program, called OPFLEX, is developed herein based on the suggested analysis method. Using the developed program, the current study conducts several numerical investigations to identify the effect of the shear deformation and varying tension. Consequently, it is confirmed that the shear deformation of internal layers reduces the fatigue damage of helical wires by delaying the increase of internal stress. It is also identified that the effect of varying tension deteriorates the fatigue life of flexible risers through a continuous change of contact pressure during bending.     

起动机用单向离合器

详细介绍起动机用单向离合器的别称、组成、分类、功能、动作原理、常用参数、安装注意事项、品质鉴别方法、检测方法、常见故障排除方法,列举了典型故障实例,并给出了单向离合器用衬套的型号与适用车型或通用及适用起动机型号。     

海洋工程用锚类型及其发展综述

海洋浮式装置锚泊定位系统的锚是使装置保持船位的关键设备。随着海洋工程的发展,已涌现出各种类型的海洋工程装置用锚,在锚的研究、设计和海上安装中大量采用先进的技术理论、试验方法和工艺技术,对各种海洋工程锚的特性、适用范围、国内外研究和发展情况作全面分析与阐述。     

船舶4冲程柴油机正时齿轮故障分析及修复探讨

在对安庆大发6PS-26H型船舶4冲程柴油机出现的齿轮故障原因进行分析的基础上,对船舶柴油机正时齿轮拆检修复过程中遇到的一些技术问题进行了探讨研究,并从机务管理的角度提出了一些管理建议,供船舶轮机人员参考。     

张力缆系泊浮体的数值波浪水槽时域模拟

为了能够快速真实地模拟波浪与张力缆系泊浮体相互作用问题,基于二维边界元格式建立了线性条件下的数值波浪水槽,并以此为基础对张力缆系泊浮体与波浪相互作用问题进行了时域数值模拟。张力缆的作用以系泊刚度的形式表达。与其他学者的相关研究结果对比表明该计算程序是可靠的,该方法可以为相关海洋工程的设计研究提供有利的参考。     

船舶变频液压舵机控制策略研究

针对船舶变频液压舵机系统存在控制死区、响应速度慢、负载影响大等特点,采用解析法与实验法相结合,获得变频液压舵机系统数学模型;采用死区补偿电压解决变频电机转速稳态误差问题;采用Z-N控制参数整定方法,确定变频电机转速PID控制参数初值。建立舵机液压模拟加载系统,实现水动力负载、周期性海浪负载和随机冲击负载的模拟。提出舵角控制采用分段控制策略,小偏差采用模糊自适应PID控制,控制算法中引入舵机负载变化因素。结果表明:该控制策略能有效抑制负载引起的舵角扰动,提高系统动态特性和鲁棒性,实现舵角快速、稳定的控制。