基于刮板输送机扁平接链环的结构分析研究

首先应用有限元分析软件ANSYS对梯齿形扁平接链环的力学简化模型进行计算分析,得出其齿联接部位详细的应力分布情况.然后据此对目前煤矿刮板输送机最为常用的扁平接链环进行动态疲劳电测实验.通过对试件疲劳断裂过程进行分析,得到接链环产生疲劳裂纹的详细演变过程,同时捕捉到接链环产生疲劳裂纹所需的循环次数为18 000次左右.此实验结果的获得为扁平接链环的合理设计及提高疲劳寿命提供了理论与实验依据.     

矿车牵引链环损伤机理研究

为了解决矿车运输过程中时常发生的牵引链环断裂现象,针对矿车牵引链环在工作过程中可能受到的损伤进行分析,利用任意弹性体间的接触理论对牵引链间的接触应力进行分析,运用有限元软件模拟连接装置间接触应力及冲击载荷对矿车连接装置造成的损伤,对其寿命进行预测,通过实验设备对牵引链进行拉伸试验,得到链环的接触刚度。研究表明,疲劳和冲击是造成链环断裂的主要原因。结论科学地分析了牵引链环的损伤机理,为研究矿车连接装置的损伤与寿命估算提供了理论依据。     

刮板输送机链轮链条啮合特性分析

链传动系统是刮板输送机的关键部件,链轮链环是链传动系统的关键部件,驱动链轮与链环的啮合力学行为与驱动链轮的磨损相互影响。为了研究链轮与链环啮合过程中链轮与链轮接触力的规律,首先从链环与链轮啮合过程进行理论分析,并对链轮链环啮合过程接触力的变化进行了分析,然后建立基于MSC.Adams的刮板输送机链轮链环虚拟样机模型,分析正常启动至长期输送功率工况下链轮与链环接触的动力学特性,分析得出环链与链轮啮合过程中接触合力、接触切向力和接触法向力的变化规律及接触力的最大值和对应的位置,最后基于LS-DYNA软件对链轮链环啮合过程进行了接触应力进分析,得出链轮链环啮合过程中接触应力最大值和对应的位置,为链轮链环啮合接触研究提供了参考。     

TH500链环钩低周疲劳失效分析

通过对环链斗式提升机链环钩失效形式和受力情况的分析，揭示了链环钩产生低周疲劳失效的原因，指出了在影响链环钩疲劳寿命的诸多因素中，链环钩与料斗之间的装配间隙是决定其疲劳寿命的主要因素，重新设计的链环钩解决了疲劳断裂问题，说明设计中所采取的措施是有效的。     

接链环受力分析与结构优化

链传动广泛地应用在采矿运输设备中,接链环是整个设备正常工作的核心。运用弹性接触和变形协调理论,研究销与接链环的接触受力及其形变。对30×108矿用弧形梯齿扁平接链环在承受最大拉力的情况下进行分析,算出接链环所受到的力,分析接链环的受力情况。通过指定设计参数,对接链环结构进行最优化设计。     

卡链工况下刮板输送机链轮链条啮合特性分析

链刮板输送机是综采工作面最重要的物料输送装备,链轮链条是刮板输送机传送系统的核心部件,链轮链条的啮合问题是传动系统最突出的问题。为了研究卡链工况下链轮与链环啮合过程中链轮与链轮接触力的规律,首先从链环与链轮啮合过程进行理论分析,并对链轮链环啮合过程接触力的变化进行了分析。然后建立基于MSC.ADAMS的刮板输送机链轮链环虚拟样机模型,分析正常运行至卡链工况下链轮与链环接触的动力学特性。分析得出圆环链与链轮啮合过程中接触合力、接触切向力和接触法向力的变化规律及接触力的最大值和对应的位置。最后基于Workbench软件对链轮链环啮合过程进行了接触应力分析,得出链轮链环啮合过程中接触应力最大值和对应的位置,为刮板输送机链轮链环的优化设计提供了理论依据。     

链轮—链环传动的受力分析与计算

本文对链轮－链环传动的受力分析，得到各链环受力大小的递推算公式及紧边与松边拉力的关系式，证明挠性摩擦的Ｅｕｌｅｒ公式仅是其特例，发现各链环力传递的等比规律。     

链轮－链环传动的受力分析与计算

本文对链轮一链环传动的受力分析，得到各链环受力大小的递推算公式及紧边与松边拉力的关系式，证明挠性体摩擦的Ｅｕｌｅｒ公式仅是其特例，发现各链环力传递的等比规律。     

环链斗式提升机的改进分析

环链斗式提升机是一种常用的离心式卸料垂直运输设备，分析这种设备的失效情况及如何改进是工程技术界研究的重要课题。本文通过对生产中使用的环链斗式提升机失效原因的分析，对链环钩、链环的计算，提出改变环链钩形状，链环钩与料斗的连接方式，板式链使用，对今后的设计、制作、改造具有一定的意义。     

环链斗式提升机的改进分析

环链斗式提升机是一种常用的离心式卸料垂直运输设备，分析这种设备的失效情况及如何改进是工程技术界研究的重要课题。本文通过对生产中使用的环链斗式提机失效原因的分析，对链环钩，链环的计算，提出改变环链钩形状，链环与料斗的连接方式，板式链使用，对今后的设计，制作 ，改造具有一定的意义。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.     

Fractional order nonsingular terminal sliding mode control for flexible spacecraft attitude tracking

This paper investigates a fractional terminal sliding mode control for flexible spacecraft attitude tracking in the presence of inertia uncertainties and extern...     

奥氏体不锈钢表面双辉等离子渗锆的动力学

利用双辉等离子渗金属技术在0Cr18Ni9Ti奥氏体不锈钢表面制备了一层均匀、致密、呈良好冶金结合的渗锆合金层,并对1 060℃下的渗锆动力学进行了研究。结果表明:随着距锆合金层表面距离的增加,锆元素的含量呈梯度递减,扩散系数逐渐减小,而扩散激活能逐步增大;在1 060℃采用双辉等离子技术渗锆时,渗锆合金层表层的空位密度为2.945×(1012~1013)cm-2,与相同温度下采用常规渗金属工艺相比,提高了1~2个数量级。     

气化炉三维扫描测量与数据处理

以德士古气化炉耐火砖的内壁蚀损检测设备为基础,对采集到的点云数据做了进一步处理.通过对数据的筛选和剔除,实现了数据点的平滑降噪细化和精简.然后利用点云对整、网格划分和分色显示等方法,最终完成了内壁腐蚀情况的三维建模.重点讨论了点云数据的预处理及后处理的方法,并根据内壁耐火砖的腐蚀阈值,提出了一种气化炉内壁腐蚀区域的识别与分割方法.对耐火砖的腐蚀分析、气化炉的生产与维修提供了可靠依据,并在工程应用中获得了一致认可.