装配式码头灌浆连接节点压弯性能试验研究

对3组装配式码头灌浆连接节点试件进行压弯试验,研究不同灌浆长度和灌浆厚度下灌浆节点的压弯承载力、延性和破坏模式。结果表明,灌浆节点试件具有较好的延性和较高的承载力,灌浆节点受压弯荷载的破坏模式为钢管的压屈破坏;压弯构件的极限承载力随着灌浆长度的增大而增大;灌浆厚度的变化对构件的承载力影响不大,但灌浆厚度增大可以提高灌浆体底部的抗裂能力,建议实际应用时适当增大灌浆厚度。     

船用无刷发电机励磁系统改装

船舶电站系统经多年运行后,其发电机控制系统器件老化,原始资料丢失,功能不完善,虽勉强能运行发电,但远不能满足船舶正常工作的供电需求。若更新发电机或订购原制造商的配件,需投入大量资金和时间,对于营运20多年的旧船来说,投入的可能性和经济性不大,而利用现行产品和技术对其进行改造,是1个很好的修复方案。文中的改装实例可为老龄船舶发电机的修复提供参考。     

国际电磁发射技术研究现状

介绍了国际电磁发射技术研究的最新进展，以及未来的发展趋势和应用方向。总结了电磁轨道炮、电热化学炮研究的热点问题和关键技术，对电磁发射技术研究的阶段和状态进行了深入分析。对于国内相关部门和技术人员有较强的参考和借鉴意义。     

恶劣天气红外热成像行人检测方法研究

为了提高智能汽车在恶劣天气对行人检测的速度和精度,本文提出一种基于YOLO V4的红外热成像行人检测方法.通过迁移学习对YOLO V4模型进行再训练,可快速而准确地实现恶劣道路环境的行人检测.     

高速动车组齿轮箱模态分析及优化设计

本文通过对国内典型高速动车组齿轮箱进行有限元仿真和试验测试,对比两种不同结构型式齿轮箱箱体的模态特征,研究分析了整体箱和分体箱对振型模态的影响,针对局部薄弱区域提出优化设计建议并进行验证.     

Tool for Predicting the Ultimate Bending Moment of Ship and Ship-Shaped Hull Girders

The present paper presents a historical review associated with the research works on hull girder strength of ship and ship-shaped structures. Then, a new program is developed to determine the ultimate vertical bending moment of hull girder by applying direct method, stress distribution method, and progressive collapse analysis method. Six ships and ship-shaped structures used in the benchmark study of International Ship and Offshore Structures Congress (ISSC) in 2012 are adopted as examples. The calculation results by applying the developed program are analyzed and compared with the existing results. Finally, the roles of the developed program and its further development are discussed.     

An exploratory investigation of the impact of ramp metering on driver acceleration behavior

Ramp metering has been proven as an effective freeway management strategy; however, the impact of ramp metering on drivers' acceleration behavior has not been fully investigated. A better understanding of acceleration behavior changes with ramp metering is critical to the adequate design of ramp metering facilities. In this study, drivers' speed and acceleration data were collected at two representative metered ramps in Los Angeles, California. The speed and acceleration profiles under meter-on and meter-off scenarios were compared. Statistical results demonstrated that ramp metering affects drivers' acceleration behavior at ramp acceleration lane. It was found that at the metered ramp with short existing acceleration length, the average acceleration rate from ramp meter stop bar to 500 ft downstream under meter-on scenario (4.72 ft./s²) is approximately 40% higher than when meter-off (3.18 ft./s²). The design of acceleration lane length for metered on-ramps should therefore take into account the potential impacts of ramp metering on driver acceleration behavior.     

轨道车辆车体涂装国产机器人生产线设计

机器人涂装替代人工喷涂,可改善作业环境,降低操作者劳动强度,提高车体油漆涂装质量.文章通过对轨道车辆车体涂装和机器人涂装的特点分析,设计适用于轨道车辆车体涂装的国产机器人生产线方案,为车体涂装国产机器人生产线的设计和应用提供指导意义.     

导电密封胶对不锈钢车体电阻点焊焊接性能影响研究

分析了电阻点焊原理,对相同的点焊搭接方式,分别采用3种工况进行焊接试验。3种工况分别采用相同焊接参数对搭接接触面涂导电密封胶和不涂导电密封胶的试件进行焊接;优化焊接参数后,对搭接接触面涂导电密封胶的试验件进行焊接。对3种工况下完成的焊接试件进行拉伸力检测试验、金相熔核尺寸检测和缺陷检测试验,对熔核直径、拉伸力、熔核内部缺陷的试验结果进行分析。试验结果表明:导电密封胶对电阻点焊的焊接性能存在影响;通过适当优化焊接参数,可以提高涂导电密封胶试件的焊接性能,焊接质量能够满足产品焊接要求。     

电动汽车动力电池热失控过程分析及预警机制设计

文章通过实验数据对热失控发生的过程进行分析,提取出关键的信号特征。设计出一套全面完整的热失控预警系统,并总结出多个报警条件,避免出现故障的误报及漏报的情况。最后介绍了热失控预警后整车及大数据的应对措施。