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...     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

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.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...