传动系统撞击现象的分析与优化

针对某后置后驱电动客车在收油门工况下产生的撞击问题,进行了整车试验测试.通过同步采集传动系统不同位置的噪声、振动以及转速信号,对撞击现象进行描述,并辨识撞击发生位置.以撞击持续时间内的信号RMS值作为评价指标,探究悬置以及齿轮副间隙对撞击剧烈程度的影响.从降低传动系统扭矩变化速率的角度出发,提出了优化撞击问题的措施.优...     

二维PSD在前照灯检测仪对光上的研究

介绍了传统的前照灯检测仪与被检车灯基准中心对准的对光方式。阐述了PSD位置传感器的工作原理,分析了利用二维PSD对前照灯检测仪进行对光的检测原理,进行了试验验证。结果表明,采用二维PSD对前照灯检测仪进行对光,其检测精度高、结构简单熏克服了传统对光方式精度低或成本高的缺点,为前照灯检测仪的研制提供了新思路。     

汽车液压感载比例阀性能试验台的研制

根据汽车感载比例阀的技术要求和检测方法,研制了液压感载比例阀性能试验台,介绍了该试验台及其控制系统的组成和功能。实际测试结果表明,该试验台测试精度高、性能稳定、装卸被测试件快速准确、测试时间短、测试结果可视化程度高、历史数据查询方便,可为液压感载比例阀的研制和在线检测提供可靠的测试依据和试验手段。     

汽车电控系统的电磁干扰故障分析及检修

论述了由点火系统、发电机及电动机、继电器、汽车音响设备等汽车内部电磁干扰源产生的电磁干扰机理。通过分析指出,电磁干扰对汽车电控系统中传感器频率信号、微电压信号和执行器线路的占空比信号会产生较大影响。结合实例,介绍了汽车电控系统的电磁干扰故障检修方法。     

助学贷款风险防范的金融创新机制研究

国家助学贷款制度实施近8年来的实践表明,在社会信用缺失和相关法律制度不健全的情况下,风险补偿机制的不科学是构成国家助学贷款可持续发展的瓶颈。文章从分析现行助学贷款中存在问题和运行机制中的弊端出发,总结发达国家的经验,结合中国的国情,探索出一条以教育担保和教育风险补偿为主的风险防范创新之路。     

客车涂层表观质量的测量评估及工艺优化

主要介绍影响客车涂层表观质量的光泽、雾影、桔皮、鲜映性、颜色等指标的测试原理和相应测试仪器,并从工艺角度探讨如何改善涂层表观质量.     

具有反馈检测功能的地铁列车开关门试验装置设计

传统地铁列车开关门试验装置,在试验过程中需工作人员确认地铁列车操纵台上的门全关指示灯是否点亮,检测效率较低.针对这种现状,设计一种具有反馈检测功能的地铁列车开关门试验装置.试验装置集成电路硬件以STM32F103C8T6型号的ARM芯片为控制核心,外围配置二极管、三极管、OLED12864显示屏、板载继电器和接线端子等...     

采用振冲碎石桩处理软基的方法

文章介绍了振冲碎石桩在某软弱地基置换加固中的成功应用,为今后类似地基采用振冲碎石桩进行置换加固的设计、施工与检测提供经验。     

Required test durations for converged short-term wave and impact extreme value statistics–Part 2: Deck box dataset

In the assessment of wave-in-deck loads for new and existing maritime structures typically model tests are carried out. To determine the most critical conditions and measure sufficient impact loads, a range of sea states and various seeds (realisations) for each sea state are tested. Based on these measurements, probability distributions can be derived and design loads determined. In air gap model testing usually only few, if any, impact loads occur per 3-hour seed. This can make it challenging to derive reliable probability distributions of the measured loads, especially when only a few seeds are generated. In addition wave impact forces, such as greenwater loading, slamming, or air gap impacts are typically strongly non-linear, resulting in a large variability of the measured loads. This results in the following questions: How many impacts are needed to derive a reliable distribution? How is the repeatability of individual events affecting the overall distribution? To answer these questions wave-in-deck model tests were carried out in 100 x 3-hour realisations of a 10,000 year North Sea sea state. The resulting probability distributions of the undisturbed wave measurements as well as the measured wave-in-deck loads are presented in this paper with focus on deriving the number of seeds and exposure durations required for a reliable estimate of design loads.The presented study is Part 2 of a combined study on guidance for the convergence and variability of wave crests and impact loading extreme values. The data set of Part 1 ([1]) is based on greenwater loads on a sailing ferry and the data set of Part 2 on wave-in-deck loads on a stationary deck box.