共查询到20条相似文献，搜索用时 31 毫秒
1.
制动盘表面螺旋纹理的消除方法 总被引：1，自引：0，他引：1
Adrián RODRíGUEZ L.Norberto LóPEZ de LACALLE Asier FERNáNDEZ Stephan BRAUN 《浙江大学学报(A卷英文版)》2014,15(1):53-60
创新要点：提出以冲刷代替传统磨削过程对制动盘进行抛光;研究扶取规定表面质晕下的最优冲刷条件。 相似文献
2.
底座板伸缩刚度对大跨度连续梁桥上CRTSⅡ型板式无砟轨道纵向力的影响 总被引：3，自引：0，他引：3
陈小平 《福建工程学院学报》2011,9(1):1-6
在结构特点分析的基础上,考虑层间传力关系和横向相邻股道的影响,建立了大跨度连续梁桥上CRTSⅡ型板式无砟轨道纵向力计算的空间一体化模型和求解方法。计算分析了列车制动和温度变化作用下底座板伸缩刚度对大跨度连续梁桥上CRTSⅡ型板式无砟轨道纵向力的影响规律,结果表明:列车制动和温度变化作用下系统纵向力变化规律相同,随着底座板伸缩刚度降低,钢轨和桥梁墩台纵向力增加,复合板、剪力齿槽和端刺纵向力减小。 相似文献
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提出了一种基于FPGA的汽车尾灯控制系统的设计方案,该系统主要包括上位机模块、主控模块、时钟分频模块、左侧尾灯控制模块、右侧尾灯控制模块和显示模块。上位机模块是通过LabVIEW软件实现的,采用硬件描述语言VHDL实现了汽车的左转、右转、刹车以及夜间行驶功能。硬件测试结果表明,设计的汽车尾灯控制系统能实现交互界面、指示灯与显示屏的同步显示,并且具有操作简单、安全性高、可靠性强等优点。 相似文献
5.
《天津大学学报(英文版)》2015,(4)
To understand the vibration noise behaviors of amorphous metal alloy core distribution transformer(AMACDT), a 10 k VA prototype was tested under no-load and short-circuit conditions, respectively. The vibration characteristics were described when rated voltage was applied to the secondary side, and the primary side was connected with different load resistances. The largest amplitude positions on the upper bracket and tank surfaces were recorded by vibration sensors arranged on the surface. A data-acquisition platform was set up for signal measurement. The vibration amplitude related to frequency was discussed, and experimental results indicated that the position with the largest amplitude accrued in the middle of the upper bracket and tank surface, at phases a and c, respectively. The experimental results suggest that magnetostrictive and electrodynamic forces play a major role in exciting the vibration noise. At the same time, some rib-reinforcements were welded on the upper bracket and tank surfaces to lessen the vibration energy, which reduced the noise. 相似文献
6.
针对汽车电动助力转向和防抱死制动系统在转弯制动工况中的相互干扰问题,建立7自由度整车模型和EPS多体动力学模型,设计了EPS和ABS两个子控制器以及具有上层协调控制功能的协调控制系统,采用PID控制方式,在Matlab/Simulink系统中,对EPS和ABS的单独控制和协调控制分别仿真,然后采用硬件在环实验验证,结果表明,采用协调控制后,汽车在转弯制动工况下的综合性能得到改善。 相似文献
7.
油料罐的液位和温度是油料仓库的非常重要的数据,人工测量是非常危险和不能实时反映状况的,本文利用传感器量测经变换后通过RS485串行通讯送到显示计算机,用Visual Basic编程实现油料罐的液位、温度值的动画和数据显示,并能设置油料罐的罐高、介质、比重及报警阀值等参数,同时具有液位和温度报警功能,并能查看报警的历史记录,可进行实时数据打印,能自动计算出每个罐的重量和体积,并将所有的参数经串行通讯送到上位主机,以便监控和管理. 相似文献
8.
超大型储液罐流固耦合振动分析 总被引：1，自引：1，他引：0
针对某超大型储液罐进行了流固耦合振动分析。首先应用ANSYS建立了储液罐-液体的流固耦合振动模型,求得了前20阶振动模态;接着分析了液面波动和储液量对耦合固有频率的影响,并取了一个高罐模型进行了高、低罐的模态分析对比;最后对"象足凸鼓"现象进行了探讨,解释了造成"象足凸鼓"现象的原因。 相似文献
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When aerodynamic braking works, the braking wings can change the flow field around the train, which may impact on the comfort
and safety. Based on a sliding mesh, the pressure wave and flow field around high-speed trains with aerodynamic braking are
analyzed. By comparing three typical intersection situations, the pressure wave of a high-speed train during braking (with
or without aerodynamic braking) is studied. The analyses indicate that the pressure wave around the high-speed train body
will change while using the aerodynamic braking, causing several pressure pulses on the surface of crossing high-speed trains.
The distances between the pressure pulses are equal to the longitudinal distances of the brake wings, but the magnitudes of
the fluctuations are less than those induced by the head of crossing trains. During the crossing, a train without aerodynamic
braking will not impact the crossing train. 相似文献
11.
为提高电动汽车能量利用率、改善车辆制动效果,依照制动踏板的不同工作状态,设计了一种并联制动控制策略。在制动踏板踩下的复合制动工况,按照相关制动法规对机械制动和再生制动进行合理分配;在滑行制动工况,以能量回收效率为目标函数,运用遗传算法优化电机在不同转速下的最佳制动转矩。分别在典型道路工况和常规制动工况下对该策略进行实车测试,结果表明:在中国轻型汽车行驶工况(CLTC-P)下,该策略的节能贡献度可达25.93%,在滑行制动工况能量回收效率较原车提升64.07%,车辆制动距离也有明显缩减。 相似文献
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潮汕地区既是一个传统书院教育比较发达的地区,又是一个较早受到西方文明冲击的地区。在清末这一场改书院为学堂的兴学运动中,中央政府、地方官员、地方士绅、宗族势力各自扮演了不同的角色,对兴学运动产生了不同的作用。潮汕地区地方势力强大、侨商众多的特点也对这场兴学运动产生了重大的影响。 相似文献
13.
Omer F. Ozdemir 《Instructional Science》2013,41(1):81-103
The purpose of this study is to understand the nature of pre-instructional knowledge transferred by students into problem situations and the change process on students’ knowledge system during classroom discussions. This study was framed by two interrelated theoretical frameworks on knowledge structures, phenomenological primitives and coordination classes. The data were collected through problem solving sessions on turning effect of forces (torques or moment) from ten participants who were seeking a degree to become physics teachers. The analysis of data showed that, in this particular context, students’ pre-instructional ideas can be characterized according to phenomenological primitives. The theoretical constructs of the coordination classes generated meaningful results to understand students’ particular difficulties in transferring the moment concept across different contexts and the change process on students’ knowledge system. The major stimulator of the change process emerged as the students’ becoming aware of the epistemological nature of their knowledge structures and searching the causal mechanisms behind physical phenomena. 相似文献
14.
随着汽车工业的进步,商用汽车逐步向高速及大型化发展,制动安全问题日益突出。安装辅助制动装置是实现大型车辆安全制动的重要途径之一。文章分析传统电涡流缓速器及液力缓速器优缺点,设计一种新型的单盘型客车磁流变缓速器。该缓速器在挤压-剪切混合模式下工作;以磁流变液（MRF）的流变特性为基础,推导该缓速器制动力矩计算公式,并在MATLAB环境下对该制动力矩公式进行仿真和分析,结果显示客车磁流变缓速器制动力矩主要与磁场强度大小有关,与转速和磁流变液间隙厚度关系很小。 相似文献
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以城市客车为平台,分析其车辆动力学各子系统的型式和参数,根据现有积累的试验测试数据,采用Trucksim软件建立整车多体动力学模型。在此基础上,对城市客车制动、转弯、冲击及扭曲等典型运行工况进行动态模拟,提取出悬架系统各部件的受力情况,包括弹簧、减震器等。结果表明,城市客车在冲击工况下悬架整体受载最大。该仿真结果能够为城市客车有限元模型各典型工况下的载荷施加提供精确的输入,有利于提高受力分析的准确度。 相似文献
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结合装置实例,对碳素钢液碱罐及碱渣管线的腐蚀原因及腐蚀机理进行了分析,探讨了温度、碱液浓度、应力等引起碱脆破裂的影响因素,提出了相应的预防措施,并通过实践应用,有效地避免了因应力腐蚀而引起的泄漏。 相似文献
17.
For in-situ composite materials, the interaction between the second-phase particles and the solidification interface attracts more attentions of people, for concerning the final distribution of the particles on the matrix. With the conception of the local solidification time, a kinematics mechanism of particle pushing into the crystal boundary during the solidification process was assumed.Through the analysis of forces acted on the particle in front of the solid/liquid interface the critical velocity criterion for the particles pushing was given. The calculation results show when the growth rate of the interface V is less than or equals to the critical velocity Vc. the particles on the solid/liquid interface is pushed into the boundary region of cellular crystals, where they are distributed as a chain-like straight, which forms a particle-strengthened in-situ composite materials. 相似文献
18.
电梯运行速度曲线的算法与仿真 总被引：4，自引：0，他引：4
文中以数学分析方法,用计算机算出了电梯制动期间的速度与距离关系v＝f（s）曲线,实现位置制动,并以仿真计算结果证明这种方法的有效性 相似文献
19.
For in -situ composite materials,the interaction between the second-phase particles and the solidification interface attracts more attentions of people,for concerning the final distribution of the particles on the matrix.With the conception of the local solidification time,a kinematics mechanism of particle pushing into the crystal boundary during the solidification process was assumed.Through the analysis of forces acted on the particle in front of the solid /liquid interface the critical velocity criterion for the particles pushing was given.The calculation results show when the growth rate of the interface V is less than or equals to the critical velocity Vc,the particles on the solid/liquid interface is pushed into the boundary region of cellular crystals,where they are distributed as a chain-like straight,which forms a particle-strengthened in-situ composite materials. 相似文献
20.
针对传统液压制动系统应用场景受限的问题,面向智能车设计新型电子液压制动系统,由车辆配备的智能驾驶系统将制动信号传递给制动系统,制动系统由助力制动子系统和备份制动子系统组成,两系统之间通过单向导通梭阀完成解耦。利用系统硬件在环实验,分析电子液压制动系统的动态特性。实验结果表明:影响电子液压制动系统建压响应性与精度的因素众多,为使得系统可以快速响应,应确保整车制动管路排气良好,尽量避免使用制动软管?同时,不宜长时间进行高压力保压工况,避免电机及电机驱动器过热从而降低制动效能。 相似文献