工作面支护与液压支架技术理论体系

工作面支护是安全高效综采的首要条件,液压支架是综采系统的核心。笔者和其合作团队持续30多年致力于综采工作面支护与液压支架技术理论的研究和实践,建立了综采工作面支护与液压支架技术理论体系框架,提出了液压支架与围岩耦合原理,建立液压支架与围岩耦合模型,分析了液压支架与围岩的强度耦合、刚度耦合和稳定性耦合规律,阐述了液压支架合理工作阻力、临界护帮力和支护系统稳定性控制策略,提出液压支架三维动态优化设计理论和方法,将围岩下沉、断裂等力、力矩以及边界条件的变化通过液压支架骨架模型传递和分解到具体的液压支架结构上,借助三维设计平台动态模拟仿真液压支架与围岩耦合作用的力学特征,优化得出对围岩最优支护效果的液压支架结构参数。提出液压支架系列型谱和工作面支护系统液压支架群组的自组织协同控制方法,将支护系统群组自组织协同控制分解为围岩自适应控制和队列保持推进控制两个控制线程,同步实现群体系统协调控制。建立了工作面支护设备技术标准体系。     

现代设计方法在液压支架设计中的应用

通过综合分析国内液压支架设计研究现状和发展趋势,提出液压支架现代设计方法,融合计算机科学、材料学、力学等学科以实现液压支架的优化设计.根据矿井资料采用FLAC3D软件对工作面进行模拟分析,得出工作面岩层的合理支护强度,从而确定液压支架的基本参数;基于MATLAB对液压支架四连杆机构进行优化设计,实现在满足支架梁端距和双纽线轨迹等约束条件下四连杆机构质量轻等优化目标;最后采用Pro/E对液压支架进行三维设计并通过ANSYS等有限元软件分析液压支架的受力状况,优化液压支架结构参数和箱体结构件截面.     

基于ADAMS的液压支架参数化建模及优化设计

为了提高支架整体性能,对支架进行优化设计。在ADAMS view环境下创建液压支架的参数化模型,针对参数化模型,以支架整体性能参数为目标函数、铰点坐标为设计变量进行优化设计。经优化使支架的前后连杆受力最大值、掩护梁最大弯矩减小,支架的支护效率得到提高。     

基于BP神经网络的液压支架支护位姿运动学分析

分析了在复杂多变的采煤工况条件下,液压支架位姿空间内变量受到驱动空间变量的耦合影响以及位姿解算应用存在的问题,设计一种基于BP神经网络的位姿空间到驱动空间的非线性转换模型,通过正向运动建立训练数据集,构造逆运动模型,能够精准快速的实现其位姿运动学计算,从而实时检测液压支架支护位姿。实验仿真结果表明,该方法控制支架位姿相对于传统方法,快速精确,提升了工作效率,为感知和调控支护位姿与跟机调控提供理论支撑。     

基于MATLAB的液压支架四连杆机构优化设计

通过对液压支架设计变量分析,采用MATLAB软件开发了一套液压支架四连杆机构优化设计系统。通过人机交互界面把支架设计变量输入到该系统,实现了对四连杆机构结构尺寸和铰接点坐标的优化设计;优化设计的四连杆机构满足双扭线轨迹曲线偏摆量,并可以降低支架连杆的重量。液压支架四连杆机构优化设计系统代替了人工设计,大大缩短了设计周期,提高了设计精度。     

并行工程环境下基于骨架模型的液压支架结构件协同设计

针对液压支架结构件协同设计中各级参数表达、传递和相关性修改困难等问题,提出了在并行工程环境下基于骨架模型的液压支架结构件协同设计方法。通过Pro/E将产品数据管理(PDM)与所有Windchill应用程序的无缝集成,利用集成PDM功能,通过布局、骨架及实体模型将Pro/E模型的控制参数分级分层表达,实现在Pro/E内管理和控制产品数据。根据此方法在Windchill平台上开发的液压支架结构件协同设计系统已经在国内某大型煤矿机械设备制造企业中得到广泛应用,提高了液压支架结构件的设计质量和效率。     

基于遗传算法的液压支架管路优化布置

以液压支架管路布局优化设计为研究对象,利用遗传算法实现管路的优化布局设计。通过关联建模方法创建液压支架的三维参数化样机模型,再利用遗传算法实现其在液压支架管路上的优化布局设计,最后利用Matlab计算出液压支架管路优化布局点的坐标。     

基于径向基神经网络的液压支架前连杆可靠性评估研究

为了解决液压支架前连杆可靠性评估困难的问题,提出了一种基于径向基神经网络的液压支架前连杆可靠性评估的方法。首先使用ANSYS参数化语言APDL对液压支架前连杆进行静力分析,确定与前连杆可靠性相关的设计变量;再使用ANSYS/PDS模块结合拉丁超立方抽样法对前连杆进行可靠性分析,获取多组前连杆不同设计变量的可靠度;最后使用径向基(RBF)神经网络拟合设计变量与可靠性之间的函数关系,建立前连杆可靠性评估模型,预测前连杆的可靠度。计算结果表明,前连杆可靠度计算结果的最大相对误差为4.46%,最小误差为1.59%。证明了径向基神经网络应用于液压支架前连杆可靠性评估的可行性,为液压支架前连杆可靠性评估提供了新的方法与思路。     

矿用液压支架控制器设计

目前我国矿井下使用的液压支架控制器主要来源依靠进口,国产的控制器在性能和稳定性方面尚不能满足需求,因此设计了一种基于微控制器STM32的液压支架控制器,介绍了系统整体架构、关键硬件设计和程序流程设计。经井下试验表明,该液压支架控制器性能稳定、功能良好,可为井下同类型的控制器设计提供参考。     

采用虚拟现实技术的煤矿虚拟液压支架运动状况仿真

研究了矿井液压支架结构、机械动作原理和求取策略,进而完成液压支架三维模型虚拟现实设计和运动分析,给出在复杂环境中的三维重建状态,实验结果表明,该方法能够较为精准地还原煤矿液压支架虚拟现实层次架构,并对矿井复杂环境完成三维重建,实现综采面工作区液压支架运动状态的远程监控。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

2014 second batch of rare earth quota released

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矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586