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1.
针对圆钢热轧批量调度问题,考虑热轧工艺约束、综合生产需求优化等因素,建立了以最小化最大完工时间、机器调整成本以及提前\拖期时间为目标的优化模型,并构造了基于种群修复的改进强度Pareto进化算法。算法以改进强度Pareto进化算法为框架实现批量序列调整,并结合问题变量的离散性特征设计编码规则,以及选择、交叉和变异等遗传进化方式;考虑问题约束的特殊性,设计种群修复策略,以修正违反热轧工艺约束的批量序列。通过基于实际生产数据的仿真实验验证了模型和算法的可行性和有效性。  相似文献   

2.
在考虑库存信息的基础上对钢管批量计划优化问题进行研究,建立了批量计划轧制位置与垛位钢坯多对多关系的批量计划模型,实现对倒垛次数的优化。结合问题特征,设计了一种基于钢坯连续倒垛的两阶段批量计划优化算法:第1阶段,确定当前最优钢坯,进而搜索同垛位上的下层钢坯,匹配最佳的连续轧制钢坯;第2阶段,针对每个轧制位置搜索垛位上的连续轧制钢坯,改进第1阶段的解。通过基于实际生产数据的实验验证,相对经典启发式算法,倒垛次数显著降低,算法和模型是可行且有效的。  相似文献   

3.
在云制造环境下,针对中小型企业加工后的板材余料造成极大资源浪费的问题,提出了一种基于语义相似度算法同时融入QoS(quality of service,服务质量)信息的分层次资源描述模型。首先,建立板材余料和板材加工设备资源的本体模型;然后,基于语义相似度算法对板材余料和板材加工设备的各个属性参数进行匹配,得到初选服务集合;最后,通过模糊QoS匹配算法将描述用户需求的自然语言转化成三角模糊数,得到服务设备的优选集合。实例仿真结果表明,所提出的方法将板材余料作为制造资源接入云制造平台,以服务的形式进行共享,增强了服务匹配过程的准确性和可靠性,实现了对板材余料和闲置的板材加工设备资源的合理调度和使用。研究结果可为云制造环境下余料和加工设备资源的匹配优选提供一种新思路。  相似文献   

4.
吴昌飞  陈会芬 《硅谷》2012,(8):105-105
介绍莱钢棒材厂中小型车间通过对现有轧机孔型系统及导卫的重新设计,对工艺的不断改进和摸索,利用Q235B为原料轧制碳素结构钢热轧圆钢的过程。  相似文献   

5.
阐述了摄象法实现热轧圆钢的直径在线检测原理。通过研究热轧圆钢运动时的物距变化摄象法在线检测的影响,提出了建立热轧圆钢运动中的相对监测系统。分析了摄象法热轧圆钢直径在线检测系统的误差,并给出了该系统综合误差的补偿方法以及测量小型棒材的综合测试结果。  相似文献   

6.
研究调整时间(费用)与工序顺序有关的Job Shop调度问题,以最小化总调整费用与总拖期惩罚费用之和为优化目标,通过建立约束规划模型,分析问题的优化特性,实现了基于约束规划的禁忌搜索算法.通过与系统搜索和局部搜索算法的结果比较,表明了此算法的有效性.  相似文献   

7.
基于人工神经网络原理,对微合金钢热轧控制参数的选取进行了研究,利用Gleeble-1500热力模拟机提取了轧制温度,应变量,应变速率和相应的应力应变曲线,并通过显微组织观察获取了实验后样品断面的奥氏体晶粒尺寸,通过归一化把实验所得数据进行处理,采用BP算法训练网络,对热轧控制参数(轧制温度,应变量,应变速率)和奥氏体晶粒尺寸之间的映射关系进行了函数逼近,建立了奥氏体晶粒尺寸神经网络模型,根据网络估测的结果可定量地进行热轧控制质量预报。  相似文献   

8.
针对约束优化问题,提出一种适于约束优化的增强差异演化算法(enhanced differential evolution algorithm for constrained optimization, ECDE).在约束处理上采用不可行域与可行域更新规则的方法,避免了传统的惩罚函数方法中对惩罚因子的设置,使算法的实现变得简单.改进了DE算法的变异操作,对选择的3个父代个体进行操作遍历,产生6个候选解,取适应值最优的为变异操作的解,大大改善了算法的稳定性、鲁棒性和搜索性能.通过4个测试函数和1个设计实例仿真,表明所提出的算法具有较快的收敛速度和较好的稳定性和鲁棒性.  相似文献   

9.
目的 选用5052铝合金与AZ31B镁合金作为复合材料进行热轧复合,研究铝/镁复合板轧制过程的数值模拟和翘曲变形控制.方法 对铝/镁复合板在不同轧制温度、轧制压下率和轧辊预加热轧制工艺下的热轧过程进行模拟.对轧制变形区铝/镁复合板的应力分布进行分析,讨论其对铝/镁复合板变形协调性的影响.最后在不同轧制工艺下进行单道次热轧实验,制备铝/镁(5052/AZ31B)复合板并与模拟结果进行对比.结果 有限元模拟和热轧实验结果表明,随着轧制压下率的增大和轧制温度的升高,铝/镁复合板的翘曲增大;将靠近铝基体侧轧辊预加热后,可以有效改善铝/镁复合板的翘曲问题.以轧制温度450℃为例,轧制压下率逐渐增大时,复合板的延伸性逐渐增大,复合板的翘曲也逐渐增大.将下轧辊预加热到50℃,其余轧制参数不变,轧制后复合板整体较为平直,翘曲明显比轧辊未预加热时小.结论 通过轧辊预加热轧制工艺可以有效控制铝/镁复合过程中的翘曲变形问题.  相似文献   

10.
为了提高热轧带材的轧制力预报精度,提出了粒子群算法和支持向量机结合的方法来预报轧制力。根据轧制原理用支持向量机建立轧制力预报的模型,通过粒子群算法优化支持向量机参数来提高预报精度。为了进一步提高轧制力预报精度,还提出了支持向量机网络与数学模型相结合的方法,对某“1+4”铝热连轧厂现场采集的5052铝合金轧制数据进行离线仿真,仿真结果可以看出支持向量机网络与数学模型结合的方法预报轧制力,提高了轧制力预报速度并使其轧制力预报精度控制在7%以内。  相似文献   

11.
A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.  相似文献   

12.
The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……  相似文献   

13.
Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.  相似文献   

14.
We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.  相似文献   

15.
Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.  相似文献   

16.
ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.  相似文献   

17.
As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.  相似文献   

18.
Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.  相似文献   

19.
TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.  相似文献   

20.
The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.  相似文献   

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