共查询到20条相似文献,搜索用时 234 毫秒
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应用有限元方法基本原理,利用有限元分析软件(ANSYS),对硝酸四合一机组底座进行模态分析和谐响应分析,分别得到了沿机组底座的虚拟轴x、y和z向的位移谐响应曲线.得出了机组底座平稳运行时,机组底座的谐响应规律及其特点,为改善机组底座的动态特性提供了一定的参考依据. 相似文献
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以某化工企业四合一机组自控系统为例,介绍了以西门子S7-414H为核心的冗余控制系统,在硝酸四合一生产过程控制中的应用。重点介绍了四合一机组的系统硬件配置和机组控制中所采取的保护策略。 相似文献
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《机械传动》2013,(9):106-109
针对某装甲车辆动力传动系统的主轴在行驶过程中极易出现故障的问题,以机械故障综合模拟实验台为研究对象,建立了其正常转子、裂纹转子以及弯曲转子的三维实体模型,运用ANSYS、ADAMS动力学仿真软件对转子系统进行了动力学仿真,得到了正常转子在刚体和柔性体状态下的位移响应曲线和碰撞力响应曲线,在此基础上,对裂纹转子和弯曲转子在柔性体状态下进行了仿真,得到了相应故障状态下的时频响应曲线,直观地揭示了柔性转子系统的动态特性,仿真和实验结果表明,在柔性转子系统中,转子中心振动位移变大,系统碰撞力降低;转子发生裂纹或弯曲故障时,振动强度会增大,这为后续装甲车辆传动系统主轴故障诊断提供一定的理论指导。 相似文献
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钱云 《气象水文海洋仪器》2006,5(3):69-72
车牌自动识别系统可以分为图像采集、图像预处理、车牌定位、车牌预处理、字符分割、字符识别几大部分.每个模块即相互关联的,又有其自身的特点和技术.车牌定位是车牌识别的基础,本文采用水平和垂直的车牌定位算法;车牌字符的分割是进行单个字符识别的前提,本文采用一种垂直投影的字符分割方法;字符识别采用了BP神经元网络的方法. 相似文献
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将水平井柔性钻柱简化为轴向载荷作用下的细长柔性梁,建立了考虑几何大变形的非线性动力学方程,并且利用多重尺度法得到了柔性梁横向振动的平均方程。因钻柱转速和轴向力是影响钻柱振动的两个主要参数,故用改变转速的方法来对平均方程进行非线性动力学响应分析,给出了一阶、二阶模态下钻柱随转速变化的分叉图和不同转速下的相图。分析结果表明,系统响应经历了从周期到混沌再到二倍周期的变化过程,振动幅值有跳变现象出现,在共振条件下,柔性旋转梁振动幅值是有限值,并非无穷大,当轴向力发生变化时,可以通过控制转速变化达到定性、定量地控制柔性钻柱横向振动的目的。 相似文献
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Seung-Kook Ro Jong-Kweon Park 《International Journal of Precision Engineering and Manufacturing》2011,12(1):115-119
We designed a novel surface motor stage supported by air bearings and driven by linear electromagnetic motors. This compact
and simple planar stage is proposed for compact-sized precision machine systems, such as micro-machine tools or measurement
systems requiring minimum X-Y stage height. Four single-phase linear motors with coils and iron cores are located under the
base plate, and air bearings and cores with permanent magnets are attached under the moving table. The hard, non-magnetic
alumina-ceramic base plate surface acts as a planar guide for the air bearings. The attractive magnetic force between the
magnets and motor cores preload the air bearing to increase vertical stiffness. By simultaneously combining actuations of
the motors, linear X and Y motion can be controlled, and angular motions can also be generated. A grid encoder is used to
control planar motion, and the system is run by a programmable numerical controller. The thrust and attractive force were
calculated using a magnetic circuit model. The designed prototype is 220 (L) × 220 (W) × 66 (H) mm3 in size with a 20 mm × 20 mm range of motion. After fabrication, basic aspects of the prototype, such as vertical stiffness
and thrust force, were evaluated. Twenty nanometers of positioning resolution was obtained for the X and Y axes, and the three
motions could be controlled independently. 相似文献
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根据物料运动理论对振动给料饥工作面运动的分析,对ZG型惯性振动给料饥进行动力学研究,得出单轴卧式和立式惯性振动给料机动力学分析方程和运动曲线图,并对这两种不同安装方式进行分析比较.得出单电机立式安装优越于卧式,完全能满足现场需要。 相似文献
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Linda M. McGrady Peter Hoepfner Craig C. Young William G. Raasch Tae-Hong Lim Jung Soo Han 《Journal of Mechanical Science and Technology》2001,15(7):1072-1076
A biomechanical study was conducted in this study to investigate if in-line skating wrist guards can effectively reduce the impact forces so as to protect the wrist from fracture. The forearm specimens with and without wrist guards were dropped using a specially designed sled to simulate the impact on the wrist while falling. A force plate was used to measure the total impact force on the dropping weight whereas a load cell was attached to the proximal end of the specimen and used to quantify the impact transmitted through the wrist joint. From the nondestructive tests, mean peak force measured from a force plate showed no difference between the guarded and unguarded groups whereas mean impulse of the guarded group was significantly greater than that of the unguarded group (p<0.01). Comparing the peak force and impulse measured from the load cell, the peak force of the guarded group was significantly less than that of the unguarded group (p<0.001), while the impulse values were similar. When the specimens were dropped from a higher position (2.5 ft vs. 1 ft), all unguarded specimens had severe wrist fractures whereas fracture was found in three out of 5 guarded specimens. Comparison of mean peak forces and impulses showed a significant difference between the guarded and unguarded groups only in the mean impulse measured from the force plate. These results suggest that the wrist guard may protect the wrist by attenuating the peak force transmitted to radius and ulnar although it may not be effective when the wrist is subjected to an impact sufficiently large to cause fractures. 相似文献
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