YU Yu-zhen
,
REN Xin-yi
,
DU Feng-shan
,
SHI Jun-jie
钢铁研究学报(英文版)
In view of characteristics of particle swarm optimization (PSO) algorithm of fast convergence but easily falling into local optimum value, a novel improved particle swarm optimization algorithm is put forward, and it is applicable to identify parameters of hydraulic pressure system model in strip rolling process. In order to maintain population diversity and enhance global optimization capability, the algorithm is firstly improved by means of decreasing its inertia weight linearly from the maximum to the minimum and then combined with chaotic characteristics of ergodicity, randomness and sensitivity to initial value. When the improved algorithm is used to identify parameters of hydraulic pressure system, the comparison of simulation curves and measured curves indicates that the identification results are reliable and close to actual situation. A new method was provided for hydraulic AGC system model identification.
关键词:
hydraulic pressing system
,
PSO algorithm
,
chaos
,
self-adaptive
,
parameter identification
REN Xin-yi
,
DU Feng-shan
,
HUANG Hua-gui
,
ZHANG Shang-bin
钢铁研究学报(英文版)
Based on the hydraulic bending control system, the electrohydraulic servo pressure control simulation model is built. Taking into account of the inadequacy of P-type immune feedback controller, an improved fuzzy immune PID controller is put forward. Drawing on immune feedback principle of biological immune system, the P-type immune feedback controller is connected with conventional PID controller in series and then in parallel with design fuzzy immune PID controller. The controller parameters can be adjusted on line by the rules of immune feedback controller and fuzzy controller. In order to gain the optimal parameters of the controller, the parameters of the controller are off-line optimized by the best multiple optimal model PSO algorithm. The simulation results indicate that the method has characteristics of small overshoot, short adjusting time and strong anti-interference ability and robustness. The quality of the strip shape can be further improved.
关键词:
electrohydraulic bending system
,
immune feedback control
,
fuzzy control
,
PSO algorithm
,
strip shape
DU Feng-shan
,
WANG Gui-guo
,
et al
钢铁研究学报(英文版)
To improve the accuracy and speed of finite element calculation, a new friction model is proposed with a layer of thin friction element being introduced between the roller and workpiece to consider the contact friction. This model is used in the three-dimensional elastic-plastic finite element model of strip rolling process. With the consideration of the geometry size and physical characteristics of intermediate medium between roller and workpiece, this stiffness of the friction element is corrected by two factors (the thickness of friction element and β factor). Without any assumption about the value and direction of friction force and neutral point position, the rolling processes is simulated using this model. The results obtained by this model have been compared with experimental results to verify the feasibility of the model. The model is of great important to the research of the friction model in the strip rolling process, and can be extended to all press-working process.
关键词:
contact friction;FEM;rolling;friction element
YU Hui
,
DU Feng-shan
,
XU Zhi-qiang
钢铁研究学报(英文版)
Roller pass is one of the key factors affecting the product quality in the retained mandrel rolling process. The metal flow condition of rolling deformation area was researched using the FEA (finite element analysis) software Marc. The influences of the pass bottom radius, the sidewall radius, the sidewall angle, the roller shoulder fillet radius, as well as the roller gap on the rolling process under the conditions of different friction were discussed. Based on these results, the changes of the workpiece exit width, the mandrel axial force, the rolling force, and the rolling torque associated with various parameters were determined, which would provide the basis for designing the pass and determining the rolling condition reasonably.
关键词:
finite element analysis
严东旭
,
刘天伟
,
龙重
,
白彬
,
张鹏程
,
黄河
,
郎定木
,
王晓红
,
朱建国
材料保护
采用单一的表面改性技术难以提高贫铀钛合金(Du-Ti)的耐蚀性能.采用等离子体浸没离子注入技术依次在Du-Ti合金表面注入N和Ti,再利用非平衡脉冲磁控溅射技术制备多层Ti/,TiN,研究了膜层的形貌、结构及耐蚀性能.结果表明:膜层厚约3μm,呈柱状结构,致密,但存在一些微缺陷,膜基结合紧密;膜层出现面心立方结构的TiN和密排六方的Ti,在DU-Ti合金界面形成了少量的UO2,没有铀的氮化物;膜层耐蚀性能较基体得到较大提高;微观缺陷是TiN层局部片状脱落的主要原因,外层TiN出现片状脱落后.注入层和内层Ti/TiN多层膜仍能有效保护基体.
关键词:
等离子体浸没离子注入
,
非平衡磁控溅射
,
复合膜
,
DU-Ti合金
,
电化学腐蚀
,
耐蚀性
高诚
,
胥蕊娜
,
陈黎
,
姜培学
工程热物理学报
格子Boltzmann方法(LBM)在计算复杂结构物理模型时具有独特优势并在模拟两相流动过程中能够高效清晰捕捉相界面.本文介绍了基于Shan-Chen多相模型的格子Boltzmann方法的理论成果以及基于二氧化碳封存的超临界两相流的模拟研究.结果表明,Shan-Chen模型在模拟两相流时符合Laplace定律,且两相层流时的速度分布和相渗曲线均与理论值吻合.二氧化碳封存过程中,较大的注入速率在提高二氧化碳残余俘获量的同时会降低其化学俘获量.
关键词:
二氧化碳封存
,
超临界两相流
,
Shan-Chen模型
李星星
,
杨科
,
张磊
,
刘强
工程热物理学报
本文提出了风力机翼型完整的性能参数体系和相应的评估方法,并以此评估了CAS-W1翼型与DU翼型的性能特征.对翼型性能的评估侧重于失速特性、非设计点特性和翼型气动性能的稳定性.评估结果表明,相对于DU翼型,CAS-W1翼型系列设计点性能和非设计点性能较好,但是失速特性和性能稳定性需要优化.
关键词:
风力机专用翼型
,
气动性能评价
,
失速特性
,
稳定性参数
欧阳艳东
,
黄翀
,
余云鹏
,
林舜辉
功能材料与器件学报
doi:10.3969/j.issn.1007-4252.2003.04.020
通过测量ITO玻璃及偏光片对各波段紫外光的光谱特性,分析比较一般偏光片和防紫外偏光片F1225DU的紫外透射光谱,从而说明新型偏光片的防紫外特性.F1225DU对紫外线有比较好的吸收,能挡住各种波长的紫外光,起防止紫外光破坏液晶显示器件的作用.
关键词:
偏光片
,
紫外光
,
液晶显示器
,
透射光谱
蒋兴元
,
魏季和
,
温丽娟
,
李波
上海金属
doi:10.3969/j.issn.1001-7208.2007.02.008
在几何相似比为1∶4的水模型上研究了150t RH装置内钢液的流动和混合特性及吹气管直径的影响.模型的吹气管内径分别为0.10、0.15和0.2 cm.所得结果表明,该装置的环流量计算式为:Qlp＝0.0291Qg0.323Du0.65Dd0.84(t/min),式中Qg-提升气体流量, Nl/min;Du和Dd-上升管和下降管内径,cm.在给定的Qg、Du和Dd下,吹气管直径din的变化对液体的流态没有显著影响,环流量则略有改变,在(0.40～0.80)cm的范围内,Qlp＝0.0304Qg0.322Du0.651Dd0.839din0.07.在Du和Dd均为53 cm、din为0.60 cm的情况下,该装置内钢液的最大("饱和")环流量约为135.1 t/min,相应的Qg为2500 Nl/min.钢包内钢液的混合效果随Qg的增大迅速提高.增大din使混合时间τm(s)略有缩短,对应于0.10,0.15和0.20 cm的孔径,τm与搅拌功率密度ε(W/t)的关系分别为:τm ∞ε-0.497,τm ∞ε-0.493和Tm∞ε-0.476.
关键词:
150t RH装置
,
水模型
,
流动特性
,
混合特性
,
物理模拟
,
吹气管直径
