Prediction of Rolling Load in Hot Strip Mill byInnovations Feedback Neural Networks

Because the structure of the classical mathematical model of rolling load is simple, even with the self-adapting technology, it is difficult to accommodate the increasing dimensional accuracy. Motivated by this fact, an Innovations Feedback Neural Networks （IFNN） was presented based on the idea of Kalman prediction. The neural networks used the Back Propagation （BP） algorithm and applied it to the prediction of rolling load in hot strip mill. The theoretical results and the off-line simulation show that the prediction capability of IFNN is better than that of normal BP networks, namely, for the prediction of the rolling load in hot strip mill, the prediction precision of IFNN is higher than that of normal BP networks. Finally, a relative complete rolling load prediction system was developed on Windows 2003/XP platform using the OOP programming method and the SQL server2000 database. With this sys- tem, the rolling load of a 1700 strip mill was calculated, and the prediction results obtained correspond well with the field data. It shows that IFNN is valid for rolling load prediction.

Research on Rolling Load Distribution Method based on Data Mining

A new method of establishing rolling load distribution model was developed by online intelligent information-processing technology for plate rolling. The model combines knowledge model and mathematical model with using knowledge discovery in database （KDD） and data mining （DM） as the start. The online maintenance and optimization of the load model are realized. The effectiveness of this new method was testified by offline simulation and online application.

Investigation on Skidding of Rolling Element Bearing in Loaded Zone

Skidding which occurs when rolling element entering into the loaded zone is prone to cause wear and incipient failure to the raceways and rolling elements. This paper presents a dynamic model to investigate the skidding of a rolling element bearing under radial load when the rolling element is entering into the load zone. In this dynamic model, the effects of the contact forces, friction forces on the rolling element-race and rolling element-cage interfaces, gravity, and the centrifugal forces of rolling elements are taken into consideration. The Hertzian contact theory is applied to calculate the non-linear contact forces. The Coulomb friction law is used to calculate the friction forces. The differential equations of rotational motion of the rolling element with regard to its central axis and the central axis of the outer ring are established respectively. The dynamic equations are then solved by using a fourth-order Runge-Kutta algorithm. The skidding characteristics of rolling element at the entry into the loaded zone are exposed, and the effects of the operating parameters on skidding behavior are carefully investigated.

The finite element analysis of articular cartilage fiber-reinforced composite model under rolling load

Articular cartilage is a layer of low-friction,load-bearing soft hydrated tissue covering bone-ends in diarthrosis,which plays an important role in spreading the load,reducing the joint contact stress,joint friction and wear during exercise.The vital mechanical function

Optimal Design of Deforming Regulation for Compact Continuous Rolling Mill with Balanced Load

If the draught of each mill stand is limited by forced bite condition for compact continuous mill,the rolling load difference between one mill stand and another is very big.If deforming regulation of relative load for each mill stand is approximate to the same,the productive capacity of compact continuous mill can be brought into full play,and also the safety running and the smooth rolling of mill can be ensured.

Effect of Load Distribution on Strip Crown in Hot Strip Rolling

In order to establish precision model, a software to calculate the strip crown of four-high hot rolling mill was developedby using affecting function method according to the strip crown calculation theory. The effect of work roll diameter,unit width rolling load, roll bending force, work roll crown, initial strip crown and reduction, etc, on load distributioneffect rate was simulated by using the software. The results show that the load distribution effect rate increaseswith the increase of strip width, work roll diameter, unit width rolling load, roll bending force, work roll crown,initial strip crown and reduction. Based on the simulation results, base value of load distribution effect rate andfitting coefficients of six power polynomial of load distribution effect rate modification coefficient were determinedconsidering all of the above parameters. A simplified mathematical model for calculating load distribution effect ratewas established.

Mechanical Analysis of Dead Load Crown and Structure Parameter of Hydraulic Elastic Bulging Roll

The dead load crown of hydraulic elastic bulging roll was discussed using the theory of elastically supported beam,and the dead load experiment was carried out. The theoretical calculation is consistent with the experimental result. The structure parameters for the thickness of roll sleeve,the length of the oil groove and the crown of roll were discussed. The fundamental principle of determining the parameters was put forward. The theoretical basis of the application of the hydraulic elastic bulging roll was established.

SELF-ALIGNING EVEN LOAD MECHANISM OF MULTI-ROW BEARINGS OF LARGE STRIP ROLLING MILL

The load distribution of multi-row bearings of large strip rolling mill is fully analyzed by 3D contact boundary element method （BEM）. It is found out that bearings are frequently worn out due to serious uneven load on the multi-row rollers. The constraint mechanism of the previous rolling system is found to be unreasonable by theoretical analysis on heavy machinery structure. A mechanism of self-aligning even load for workroll bearing of 2 050 mm hot rolling mill of Baoshan I＆S Co. is developed. This device is manufactured with particular regard to the structure of 2 050 mm hot rolling mill mentioned above. Hence, uneven load on multi-row bearings is greatly relieved and their lives are remarkably prolonged. Meanwhile, theoretical analysis and on-spot tests prove the rationality and validity of the device.

Web Tension Regulation of Multispan Roll-to-Roll System using Integrated Active Dancer and Load Cells for Printed Electronics Applications

The mass production of primed electronics can be achieved by roll-to-roll（R2R） printing system, so highly accurate web tension is required that can minimize the register error and keep the thickness and roughness of printed devices in limits. The web tension of a R2R system is regulated by the use of integrated load cells and active dancer system for printed electronics applications using decentralized multi-input-single-output（MISO） regularized variable learning rate backpropagation artificial neural networks. The active dancer system is used before printing system to reduce disturbances in the web tension of process span. The classical PID control result in tension spikes with the change in roll diameter of winder and unwinder rolls. The presence of dancer in R2R system shows that improved web tension control in printing span and the web tension can be enhanced from 3.75 N to 4.75 N. The overshoot of system is less than ±2.5 N and steady state error is within ± 1 N where load cells have a signal noise of ±0.7 N. The integration of load cells and active dancer with self-adapting neural network control provide a solution to the web tension control of multispan roll-to-roll system.

仿生侵蚀介质对滚刀/大理岩滚动摩擦磨损行为的影响

目的对比去离子水和仿生侵蚀介质2种工况下,滚刀/大理岩摩擦副在不同法向载荷作用下的滚动摩擦磨损行为,阐明仿生侵蚀介质对大理岩破碎去除和滚刀磨损的影响规律和作用机制,为化学手段辅助提升全断面隧道掘进机(TBM)破岩效率提供参考。方法表征自制仿生侵蚀介质对大理岩和H13钢滚刀的腐蚀性,基于自制滚压破岩模拟试验机研究滚刀/大理岩摩擦副的滚动摩擦磨损行为。结果仿生侵蚀介质对滚刀无明显腐蚀性,但会诱导大理岩表面产生次生裂隙和溶蚀孔,弱化岩石表面的力学性能。在法向载荷为45、75、105N时,相较于去离子水工况,在仿生侵蚀介质工况下大理岩的磨损体积分别提高了25.3%、9.3%、17.5%,滚刀破岩比能分别下降了28.3%、11.4%、20.0%。在法向载荷为45 N时,岩石表面的破坏形式主要为矿物颗粒破碎剥落。在法向载荷为75N时,岩石的去除量明显增大,表面形成了密实核。在法向载荷为105N时,岩石表面发生显著开裂和去除现象。结论仿生侵蚀介质能促进大理岩的破碎和去除,降低滚刀磨损和破岩比能。仿生侵蚀介质的作用受到岩石破坏形式的影响,在法向载荷较低时,岩石表面破坏形式以矿物颗粒剥落和密实核形成为主,仿生侵蚀介质仅作用于岩石表层,其效果有限;在法向载荷较高时,岩石表面会产生裂纹和开裂,有利于仿生侵蚀介质向岩石内部的渗透,刀具的破岩效率显著提高。

电能型-功率型混合储能日前-日内协同滚动调度策略

混合储能可以利用不同类型储能在电量和功率上的不同优势。然而,在滚动优化调度中,电能型储能资源(如电池储能)容易因较短的日内滚动时间窗而限制其削峰填谷的能力;而功率型储能资源(如超级电容)又容易因较长的日前时间窗而影响其平抑风电波动的效果。针对以上两种问题,文中提出一种同时考虑电能型和功率型储能资源的日前-日内协同滚动调度策略。首先,针对电能型储能削峰填谷能力受限的问题,将日内滚动周期扩展到一天中的剩余时间,并将调度范围划分为时间分辨率不同的两个部分,从而使该部分储能资源尽可能参与削峰填谷,同时提升模型的求解效率。然后,针对功率型储能平抑波动能力受限的问题,通过对波动量的极值点统计分析,提出有限时间窗电量约束策略,从而避免该部分储能资源因过度参与削峰填谷而导致能量不足。算例表明,提出的调度策略能够发挥不同储能资源的调度潜力,在削峰填谷的同时平抑风电波动,提升风电消纳能力。

基于SolidWorks和Ansys的铁路卷状货物横向限位运输座架设计

目的针对卷状货物在铁路运输途中常发生横向窜动,造成货物损伤、危及行车安全等问题,基于当前主流运输座架和技术经验,设计一款安全可靠、适用多种车型、可叠放回送、可循环使用、适合多种规格卷状货物、带有横向限位装置的运输座架。方法根据《铁路货物装载加固规则》,制定最不利工况下的卷状货物装载加固方案;依据《钢结构设计标准》及敞车、平车的结构,确定运输座架的结构和材料;通过SolidWorks-Ansys对运输座架进行建模和有限元分析,得到卷钢座架变形及应力的变化情况。结果通过分析可知,运输座架会受到垂向力、纵向力,其最薄弱部分的应力分别为355.14、341.99 MPa,位移变形量分别为0.55、1.069 mm,符合规定;在最不利工况下,横向限位挡件的最大应力为28.89 MPa,最大变形量为0.04 mm,符合规定。结论设计的铁路横向限位运输座架安全可靠,可有效防止货物发生横向窜动;叠装回送,可实现重去重回。该设计填补了现有运输座架对卷状货物无法进行横向刚性加固的空白,对当下卷状货物运输发展具有较大的促进作用。

变载荷作用下的角接触球轴承动力学分析

为研究球轴承在变载荷作用下的动力学行为,建立了角接触球轴承的动力学模型,并在不同的载荷谱下进行了角接触球轴承的动力学计算,对比了不同载荷谱作用下球与内外圈的接触角和接触载荷以及球的自转角速度和公转角速度随时间的变化。结果表明:载荷瞬时变化产生的冲击会导致球与内外圈的接触载荷和接触角发生突变,且变化幅度与冲击载荷大小相关;在受载荷冲击后,球的自转角速度和公转角速度也会发生突变,并且随轴承的转动,球的自转角速度和公转角速度会最终达到一个稳定值;载荷变化幅度越大,变化频率越快,轴承运动的变化幅度就越大。

主燃油泵轴承剥落故障探究

【目的】查明某型发动机配套主燃油泵所用滚子轴承内外滚道剥落的原因,可以提高主燃油泵寿命和可靠性。【方法】本文对主燃油泵所用滚子轴承的结构组成、配合间隙、滚道受力等进行仿真分析。【结果】导致滚道剥落的原因为偏载引起的局部应力超出材料的许用范围。本研究还查出了轴承偏载的原因。针对偏载原因制定了控制间隙和滚子修形的措施。经仿真分析和试验验证,证明了措施的可行性。【结论】该问题的解决提高了主燃油泵的寿命和可靠性,同时为同类滚动轴承的设计和剥落故障分析提供了依据和参考方案。

港口桥式起重机械负载防摇控制方法研究

为了有效解决港口桥式起重机械负载振荡问题,提出一种港口桥式起重机械负载防摇控制方法。以港口桥式起重机械为基础,对受力情况展开全面分析,利用拉格朗日原理构建动力学方程,并且采用小角度近似处理的简化方法计算对应的动力学方程,为构建防摇控制器提供理论基础。引入模糊控制推理逻辑,设计出一种模糊自整定PID控制器,将控制器引入到港口桥式起重机械中,实现港口桥式起重机械负载防摇控制。实验分析证明,所提方法可以获取更加满意的港口桥式起重机械负载防摇控制结果。

装配式组合梁新型剪力键受力性能试验研究

为解决装配式组合梁剪力键存在的问题,通过在预制混凝土桥面板中预埋栓钉和钢板,再与钢梁翼缘焊接的方式改进剪力键的设计,并对新型栓钉剪力键试件进行推出试验,研究其破坏形态、荷载-滑移曲线、抗剪刚度等。结果表明:试件破坏时栓钉均被剪断,表现出延性破坏;试件的荷载-滑移曲线可以划分为弹性阶段、弹塑性阶段和破坏阶段3个阶段;在相对滑移量约为2 mm时,试件达到极限承载力,随着栓钉数目的增加,栓钉的承载力和抗剪刚度均减小。通过计算可知,该新型栓钉剪力键的承载力能够满足工程设计的需要。

基于改进斑点鬣狗算法的热轧带钢负荷分配智能优化

针对热连轧过程中由于负荷分配不均匀导致板形控制效果不佳的问题,以传统的轧制机理为基础建立负荷分配均匀、板形良好的目标函数,分别采用斑点鬣狗算法和改进斑点鬣狗算法进行单目标和双目标的负荷分配的优化求解。结果表明,改进斑点鬣狗算法将末机架的相对凸度差从0.000 834 5降低到0.000 014 83和-0.000 026 34,且在允许的范围内,上游机架负荷分配合理,充分发挥了轧机的轧制能力。

特重车辆荷载作用下独柱墩连续箱梁弯桥抗侧倾和抗滑移分析与加固构造

在分析特重车辆作用下独柱墩连续箱梁弯桥倾覆倒塌事故的基础上,提出导致连续箱梁桥发生倾覆的重要原因是主梁在特重载偏心作用下产生侧倾与滑移的共同作用.以湖北省鄂州市发生倾覆落梁事故的三跨连续箱梁弯桥为工程背景,开展抗侧倾和抗滑移理论计算和有限元分析,提出桥梁整体化的抗滑移加固构造.结果表明,该桥梁具有较高的抗侧倾能力,但抗滑移能力明显不足,特重载偏心作用下产生的切向力显著大于支座的最大抗力,主梁极易发生滑移而倾覆.单纯增大桥梁抗侧倾能力的加固方法对提高主梁的抗倾覆效果不佳,应同时增加桥梁的抗滑移能力.该桥梁采用整体化抗滑移加固构造后,具有较强的抗滑移和抗侧倾能力,在特重载偏心作用下主梁不会发生倾覆破坏.

考虑磨损的全断面硬岩掘进机主轴承寿命计算

主轴承是全断面硬岩掘进机传动系统的重要部件,在恶劣的服役环境下会因磨损疲劳复合作用导致寿命计算困难,分散性大,因此提出一种考虑磨损的TBM主轴承寿命预测模型。首先,为确定主推滚子载荷,建立主轴承载荷分布计算模型并通过有限元模型进行验证;然后,为获得滚子接触特性,建立滚子与滚道接触的局部有限元模型,以最大接触载荷为输入进行求解;最后,基于Archard磨损理论与连续损伤力学理论对主轴承疲劳寿命进行预测。某4.8 m级TBM主驱动轴承的寿命预测结果表明:滚子中心处不发生磨损,磨损深度从滚子中心到两端先增大后减小,导致最大接触应力从最初边缘处的1253 MPa增大至中心处的1584 MPa,滚子有效接触长度从94 mm增大至96 mm,计算得到主轴承寿命为15778 h。

胎面花纹对轿车轮胎室内性能的影响

以205/55R1691V轿车轮胎为研究对象,通过在原胎面花纹的基础上增加横向沟槽设计并进行钢片雕刻,研究胎面花纹对轮胎外缘尺寸、静负荷性能、滚动阻力和室内噪声的影响。结果表明:胎面花纹变化对轮胎的外缘尺寸没有影响,对轮胎的静负荷性能、滚动阻力和室内噪声有较大影响;与原花纹轮胎相比,增加横向沟槽花纹轮胎的接地面积和滚动阻力增大,室内噪声降低。