基于 EDEM 的输送带动态跑偏仿真分析

针对带式输送机在运输物料过程中由于落料不均易出现输送带跑偏的问题,通过离散元法进行分析。运用单因素控制变量法进行 EDEM 仿真计算,分析了不同落料高度、不同落料速度及不同湿度状态下对物料流在导料槽出料口处速度与输送带跑偏的影响。通过对比与研究发现,物料落料高度、落料速度及物料颗粒湿度对带式输送机转运系统会产生影响,在此情况下单一改变某一参数会降低输送带跑偏趋势。研究发现,在一定条件下输送带跑偏趋势随落料高度增加而增加,也随落料速度增加而增加,但是与物料湿度成相反趋势,即物料湿度增大,输送带跑偏趋势减小。同时需注意物料湿度增加,物料附着导料槽影响下段输送带受料。     

浅析如何提高电子配料秤称重计量精度

本文主要介绍了电子配料秤称重计量系统的特点和工艺要求,以及提高称重精度可靠性的措施。     

静态电子秤在香料厨房中的应用

香料厨房设备中采用压差传感器和电磁流量计(质量流量计)进行计量时,存在着系统综合精度较低的问题,为此,在香料厨房设备中应用了静态电子秤.在香料厨房料液配制过程中,采用称入法和称出法相结合的计量方法,以满足料液配制品种多、用量差别大的要求.配料工艺流程经过优化后,集中配料的罐体数量减少20%～30%,提高了料液配制的灵活性,系统综合配制精度达到0.5%.     

失重秤运行参数的设计计算

失重秤是一种定量称重给料设备,它将动态称重和静态称重结合,间断给料和连续出料结合,适用于微细物料的称重和配料控制。在设计失重秤时,应根据工艺过程要求,计算重新装料体积、重新装料速度、每小时重新装料次数、称重料仓容积等关键运行参数,以保证失重秤正常运行。     

水泥混凝土搅拌站骨料称量方法探究

正1.称量系统结构和工作原理水泥混凝土搅拌站称量设备主要由骨料计量配料系统、水泥计量配料系统、水计量配料系统、外加剂计量配料系统、输料装置、搅拌装置、卸料机构和电控系统等组成。本文主要研究骨料计量配料系统的称量计量方法。骨料称量斗置于料仓下方,以便于料仓直接投料。每种骨料经过独立计量,再由胶带输送机送入骨料储藏仓。称量斗下方安装的称重传感器,用于将     

混凝土拌和站配料计量不准的原因

一套简易混凝土拌和站,出现了配方料值与实重料值相差很大,并在多次调整配料落差参数重新配料时,微机会发出报警,提示配料计量不准确。依据故障现象,首先检查了控制仪表所有外部连接及各种称重传感器的连接线路,均未发现故障原因。 此拌和站设备设有3种报警装置。 1.配料报警     

基于粒子群模糊PID的茶叶包装机定量称重控制

针对茶叶包装机定量称重控制系统受到空中注料对料斗冲击、料斗振动及茶叶大小不均等因素影响,造成茶叶定量称重控制系统存在非线、时变及滞后的问题,提出粒子群模糊PID控制策略应用茶叶定量称重系统,利用粒子群算法全局寻优模糊控制的量化因子和比例因子参数,弱化专家经验的盲目性和主观性,以提升控制系统的响应速度、收敛速度。利用OPC技术实现WINCC和MATLAB软件通讯采集控制系统数据,完成控制系统模型辨识,建立Simulink仿真模型对粒子群模糊PID控制器和模糊PID控制器进行仿真对比,结果表明:粒子群模糊PID控制器具有响应速度快、鲁棒性强的优点,提高了茶叶定量称重控制系统的精度,为精茶制造企业提高经济效益提供借鉴。     

一种静态计量方式下的动态称重系统的研制

本文介绍的高精度动态称重系统适用于颗粒状物料的散料计量，本装置采用不定量式静态称重方式，保证了较高的计量精度；同时，通过双秤斗分时计量，使整机系统处于动态工作模式下；为提高秤体安装精度和降低成本，采用了单只传感器组件。这些结构特点保证了整机系统的高性能、低价格、结构紧凑，并且安装方便，可广泛用于粮库、油厂、面粉厂、化工厂等企业。     

散货抓斗卸船机同时卸装料系统的研制

<正>通常,散货抓斗卸船机带式输送系统的工艺流程是:料斗中的物料通过料斗出料口下方的振动给料机输送到分叉落料管中,再经分叉落料管进入布置在码头上的带式输送系统,最终流入后方的堆场或工作面。由于只能进行卸料操作,如需进行物料的转驳装船作业,只能在料场和码头之间另建一套由斗轮取料机、带式输送机、装船机组成的输料系统,加大了设备、土建工程投资。本文结合传统散货抓斗卸船机工艺流程,对其进行了改进,研制、设计出了一种新型散货抓斗卸     

基于EDEM的粉料称量冲击载荷仿真研究

称量系统作为混凝土搅拌站的核心模块,称量精度直接影响混凝土的质量和性能。针对落料冲击对称量精度的影响,在分析称量机理的基础上,通过三维软件建立称量系统简化模型,选取Hertz-Mindlin非线性接触模型进行离散元EDEM落料称量仿真,使用冲击系数表征冲击载荷大小。根据仿真结果对称量装置进行优化,设计了缓冲装置锥形溜料板,并对改进后称重模型进行仿真分析,对比冲击系数发现,改进后对称体的冲击载荷明显减小,称量精度得到了有效改善,为混凝土机械的设计与优化提供了理论依据。     

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...     

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。     

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...     

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.     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.