三拐曲轴锻造工艺研究应用

采用120°角度尺等简单自制工辅具,实现了对曲拐空间相位角度和偏心量的控制,减少三拐曲轴工艺重量、降低材料成本,成功整体锻造了隔膜泵三拐曲轴,实现了自由锻无错移大偏心曲拐成形,降低了加工周期,外形尺寸及内部质量均符合技术要求。     

深海压力补偿器密封性能分析

密封是深海压力补偿器的关键技术之一,为了准确分析由法兰-膜片-螺栓组成的密封结构在海上和深海环境下的密封性能,利用ANSYS软件建立了该结构三维模型。通过计算预紧应力来分析膜片的密封性能以及工作深度,螺栓预紧力、安装位置和膜片厚度、宽度等因素对密封性能的影响。结果表明:为了满足密封要求,海上环境下螺栓预紧力应大于4 500 N;深海环境下膜片预紧应力取决于工作深度且应力大小与环境压力基本一致。     

往复式隔膜泵功率经验公式回归分析

高浓度尾矿浆长距离、大流量管道输送的关键设备是往复式隔膜泵,隔膜泵的功率计算尤为重要。目前泵功率计算影响因素多、方法复杂。为简化隔膜泵功率计算并为管道输送方案优化提供便利,在统计大量SGMB、DGMB系列隔膜泵输送尾矿浆、化工料浆、水煤浆及氧化铝料浆4类料浆时的额定功率、流量、压力数据基础上,结合Origin软件,对不同结构、不同输送对象隔膜泵的额定功率与额定流量及压力间的关系进行拟合分析,得到经验公式并进行了差异性分析。结果表明,隔膜泵的功率与额定流量和压力之积成正比,且不同结构、不同输送对象隔膜泵的功率经验公式差异程度低,因而可使用统一的隔膜泵功率计算经验公式。     

水厂铁矿尾矿隔膜泵输送工艺研究与应用

水厂铁矿原尾矿输送工艺系统落后、管理复杂、能耗高、运行成本高,为降低矿山生产成本,对尾矿输送工艺采用隔膜泵进行改造。针对隔膜泵对入料介质的要求,通过对国内众多矿山隔膜泵给料工艺进行考察分析,结合水厂铁矿现场设备和生产实际,提出了尾矿经圆筒筛隔渣生产建筑用砂,隔渣后的尾矿经过深锥浓密机浓缩后给料到隔膜泵进行输送的新工艺。新工艺实施后,隔膜泵入料尾矿浆中+0.833 mm颗粒粒级含量仅为0.61%,基本将 1 mm以上粗颗粒剔除,能够生产出产率8.28%、模数2.5、含泥量2.5%以下的合格建筑用砂。利用改造后的深锥浓密机实现了隔膜泵稳定、均匀给料。新工艺实现了尾矿资源的高效利用,开拓了矿山企业新的经济增长点,同时满足了隔膜泵安全稳定运行的需要。     

Quadrilateral shear panel

Various models of structures and structural elements use an assembly of stringers and shear panels. The normal forces in the stringers can vary linearly and the membrane panels have constant shear. Often, these shear panels can be just rectangular but sometimes shear panels with a non-rectangular shape need to be used. In this paper a mathematical formulation is presented for a linear–elastic shear panel with a quadrilateral shape. The panel stiffness matrix is derived by the discrete element method, which yields a simple and efficient computational formulation. Comparison with finite element computations shows that the stiffness matrix is sufficiently accurate for engineering design.     

SMW工法在深基坑支护工程中的应用

介绍了用SMW工法地下连续墙在深基坑支护工程中的一次成功工程实践。对地下水位较高的深基坑工程 ,选用SMW工法地下连续墙 ,可以同时起到挡土和防渗的作用 ,达到了缩短工期和降低成本的目的。     

一种摩擦离合器膜片弹簧载荷变形特性修正计算方法

由于常用的A-L法计算膜片弹簧载荷特性曲线存在较大误差的问题,文中分析了分离指结构对膜片弹簧载荷变形特性的影响,提出了分离指影响系数概念.利用正交试验设计,采用多元回归分析的方法,拟合得到分离指影响系数同三个转换参数的函数关系表达式.把分离指影响系数添加到碟形弹簧精确算法S-W法的计算公式中,得出了包含分离指部分影响的...     

Fabrication and electrostatic actuation of thin diaphragms

In this paper, two kinds ofp ⁺ diaphragms are fabricated. One is flat, and the other is corrugated to release the residual stress resulted from the diffusion process. The two diaphragms are electrostatically actuated, and the center deflections of the diaphragms are measured for various frequencies. The static deflections of the flat diaphragm and the corrugated one estimated from the test results are compared with the calculated static deflections under residual tensile stress. The experimental result and the calculated result agree in the case of the flat diaphragm with a reasonable residual stress, but it is not true for the corrugated diaphragm. In the calculation, it is estimated that the corrugated diaphragm deflects more than the flat one. In the experiment, however, the corrugated diaphragm deflects less than the flat one.     

一种硅微压阻式压力传感器的研究

研究了一种量程为20kPa的压阻式微压力传感器,同时采用ANSYS仿真得出影响传感器性能的一些规律。应用小挠度理论设计计算了压阻式硅传感器方形弹性膜片结构,并对圆形膜片与方形膜片进行了比较,同时设计了硅芯片以及压敏电阻的尺寸和阻值。通过模型分析和对方型硅膜片的模拟计算,确定了压敏电阻最佳放置位置,来提高灵敏度;并在各个不同的压力下仿真出应力分布图、得出输入—输出关系图及应力峰值。研究为压阻式微压力传感器的结构以及优化、稳健设计提供了一定参考。     

An experimental intercomparison of gas meter calibrations

This paper presents four calibrations carried out in four different, independent, metrological accredited laboratories, on six diaphragm gas meters for domestic use (G4). The aim of this study is to evaluate the degree of metrological agreement among different calibration results, by means of the assessment of suitable factors (compatibility index, also known as normalized error). This application study is quite interesting in the field of “legal metrology”, when often conformity assessment are requested in order to assure the adequate behavior of a domestic gas meter. The six gas meters were calibrated in four different laboratories, each of them characterized by different values of the calibration uncertainty (also called CMC = Calibration and Measurement Capability, or BMC = Best Measurement Capability, or Minimum Uncertainty). Two alternative approaches about the metrological compatibility are introduced: a quantitative approach and a qualitative approach. The calibration results show that for diaphragm gas meters for domestic use, the metrological agreement should be preferable by means of the qualitative approach.