ZTE Corporation (ZTE),a leading global provider of telecommunications equipment and network solutions,on February 12,2009,released a unique Unified Open Environment (UOE) platform that will make it easier fortelecom o...ZTE Corporation (ZTE),a leading global provider of telecommunications equipment and network solutions,on February 12,2009,released a unique Unified Open Environment (UOE) platform that will make it easier fortelecom operators展开更多
In the given work results of researches asymmetric rolling on reversive mill 5000 are considered. By definition of boundary modes of asymmetry and an opportunity of application results of precomputations are resulted ...In the given work results of researches asymmetric rolling on reversive mill 5000 are considered. By definition of boundary modes of asymmetry and an opportunity of application results of precomputations are resulted in production for various circuits of rolling. Results of influence of asymmetric rolling on physic and mechanical properties, structure and geometry hot sheets are shown, recommendations to introduction of modes of asymmetry in a production cycle of manufacturing of sheet-rolling production of the improved quality are展开更多
In order to lucubrate the rolling characteristic of the two stands reversible cold rolling mill and establish the tension and thickness control strategy, the steady-state characteristic simulating program was establis...In order to lucubrate the rolling characteristic of the two stands reversible cold rolling mill and establish the tension and thickness control strategy, the steady-state characteristic simulating program was established using the steady-state continuous rolling theory. The influences of each factor on exit thickness under different tension control methods were analyzed. The results show that, the influence of the entry stand gap on exit thickness is significant and it changes little with different tension control methods. As a result, the entry stand gap can be used as the main control method of exit thickness, whereas rolling speed of any stand and roll gap of the exit stand can be used to adjust the inter-stand tension. The results are beneficial for thickness and tension control of the two stands reversible cold rolling mill.展开更多
Although a great deal of research has been dedicated to the synthesis of spiral bevel gears, little related to reverse engineering can be found. An approach is proposed to reverse the machine-tool settings of the pini...Although a great deal of research has been dedicated to the synthesis of spiral bevel gears, little related to reverse engineering can be found. An approach is proposed to reverse the machine-tool settings of the pinion of a spiral bevel gear drive on the basis of the blank and tooth surface data obtained by a coordinate measuring machine(CMM). Real tooth contact analysis(RTCA) is performed to preliminary ascertain the contact pattern, the motion curve, as well as the position of the mean contact point. And then the tangent to the contact path and the motion curve are interpolated in the sense of the least square method to extract the initial values of the bias angle and the higher order coefficients(HOC) in modified roll motion. A trial tooth surface is generated by machine-tool settings derived from the local synthesis relating to the initial meshing performances and modified roll motion. An optimization objective is formed which equals the tooth surface deviation between the real tooth surface and the trial tooth surface. The design variables are the parameters describing the meshing performances at the mean contact point in addition to the HOC. When the objective is optimized within an arbitrarily given convergence tolerance, the machine-tool settings together with the HOC are obtained. The proposed approach is verified by a spiral bevel pinion used in the accessory gear box of an aviation engine. The trial tooth surfaces approach to the real tooth surface on the whole in the example. The results show that the convergent tooth surface deviation for the concave side on the average is less than 0.5 μm, and is less than 1.3 μm for the convex side. The biggest tooth surface deviation is 6.7 μm which is located at the corner of the grid on the convex side. Those nodes with relative bigger tooth surface deviations are all located at the boundary of the grid. An approach is proposed to figure out the machine-tool settings of a spiral bevel pinion by way of reverse engineering without having known the theoretical tooth surfaces and the corresponding machine-tool settings.展开更多
For entire roller embedded shapemeter roll, the relationship between the value of interference fit and the sensor pre-pressure, and the pressure transfer performance of shapemeter roll were analyzed by elasticity theo...For entire roller embedded shapemeter roll, the relationship between the value of interference fit and the sensor pre-pressure, and the pressure transfer performance of shapemeter roll were analyzed by elasticity theory during the cold reversible rolling process. Considering the influence of strip temperature on the interference fit, the distributions of contact pressure of the framework's top surface and the sensor pre-pressure on different values of interference fit were analyzed by the finite element technology. The results show that the contact pressure of the framework's top surface and the sensor pre-pressure increase with the increase of the value of interference fit. When the value of interference fit is between 0.05 mm and 0.09 mm, roll body's inner hole surface, the framework and pressure magnetic sensitive component don't separate from each other, and the sensor works in the linear segment of characteristic curve, so the normal operation of shapemeter roll is guaranteed.展开更多
外卖配取过程中实时订单的不断插入具有强烈的不确定性,需持续进行滚动优化以动态更新配取路径。动态条件下,有效地合并取餐与配送作业(dynamic order combination,DOC)可显著减少冗余路径。本文将动态配取路径规划问题转化为变长开放...外卖配取过程中实时订单的不断插入具有强烈的不确定性,需持续进行滚动优化以动态更新配取路径。动态条件下,有效地合并取餐与配送作业(dynamic order combination,DOC)可显著减少冗余路径。本文将动态配取路径规划问题转化为变长开放链滚动优化问题,并构建多目标滚动配取路径规划模型对DOC与节点排序进行集成决策。考虑滚动优化框架下紧前决策对紧后决策的调度影响,模型在兼顾配取效率和客户满意度的同时,考虑了基于look-forward的滚动调度后效性。针对该模型,本文基于NSGA-Ⅲ框架开发了多目标元启发式算法进行求解,并设计了基于插入限制规则的元胞数组解编码和混合PMX&SBX交叉方式以适应模型的复杂可行域结构。通过一系列的仿真实验,本文验证了所提出的模型和算法的有效性与优越性。展开更多
文摘ZTE Corporation (ZTE),a leading global provider of telecommunications equipment and network solutions,on February 12,2009,released a unique Unified Open Environment (UOE) platform that will make it easier fortelecom operators
文摘In the given work results of researches asymmetric rolling on reversive mill 5000 are considered. By definition of boundary modes of asymmetry and an opportunity of application results of precomputations are resulted in production for various circuits of rolling. Results of influence of asymmetric rolling on physic and mechanical properties, structure and geometry hot sheets are shown, recommendations to introduction of modes of asymmetry in a production cycle of manufacturing of sheet-rolling production of the improved quality are
基金Item Sponsored by National Basic Research Program of China (2011CB612204)Doctoral Scientific Research Fund of Taiyuan University of Science and Technology of China (20112007)
文摘In order to lucubrate the rolling characteristic of the two stands reversible cold rolling mill and establish the tension and thickness control strategy, the steady-state characteristic simulating program was established using the steady-state continuous rolling theory. The influences of each factor on exit thickness under different tension control methods were analyzed. The results show that, the influence of the entry stand gap on exit thickness is significant and it changes little with different tension control methods. As a result, the entry stand gap can be used as the main control method of exit thickness, whereas rolling speed of any stand and roll gap of the exit stand can be used to adjust the inter-stand tension. The results are beneficial for thickness and tension control of the two stands reversible cold rolling mill.
基金supported by Aero Propulsion Test and Demonstration of Commission of Science and Technology and Industry for Nation Defense,China (Grant No. APTD-1001B)
文摘Although a great deal of research has been dedicated to the synthesis of spiral bevel gears, little related to reverse engineering can be found. An approach is proposed to reverse the machine-tool settings of the pinion of a spiral bevel gear drive on the basis of the blank and tooth surface data obtained by a coordinate measuring machine(CMM). Real tooth contact analysis(RTCA) is performed to preliminary ascertain the contact pattern, the motion curve, as well as the position of the mean contact point. And then the tangent to the contact path and the motion curve are interpolated in the sense of the least square method to extract the initial values of the bias angle and the higher order coefficients(HOC) in modified roll motion. A trial tooth surface is generated by machine-tool settings derived from the local synthesis relating to the initial meshing performances and modified roll motion. An optimization objective is formed which equals the tooth surface deviation between the real tooth surface and the trial tooth surface. The design variables are the parameters describing the meshing performances at the mean contact point in addition to the HOC. When the objective is optimized within an arbitrarily given convergence tolerance, the machine-tool settings together with the HOC are obtained. The proposed approach is verified by a spiral bevel pinion used in the accessory gear box of an aviation engine. The trial tooth surfaces approach to the real tooth surface on the whole in the example. The results show that the convergent tooth surface deviation for the concave side on the average is less than 0.5 μm, and is less than 1.3 μm for the convex side. The biggest tooth surface deviation is 6.7 μm which is located at the corner of the grid on the convex side. Those nodes with relative bigger tooth surface deviations are all located at the boundary of the grid. An approach is proposed to figure out the machine-tool settings of a spiral bevel pinion by way of reverse engineering without having known the theoretical tooth surfaces and the corresponding machine-tool settings.
基金Project(2011BAF15B00)supported by the National Science and Technology Support Plan of ChinaProject(E2011203004)supported by the Hebei Provincial Natural Science Iron and Steel Joint Research Fund Program,China
文摘For entire roller embedded shapemeter roll, the relationship between the value of interference fit and the sensor pre-pressure, and the pressure transfer performance of shapemeter roll were analyzed by elasticity theory during the cold reversible rolling process. Considering the influence of strip temperature on the interference fit, the distributions of contact pressure of the framework's top surface and the sensor pre-pressure on different values of interference fit were analyzed by the finite element technology. The results show that the contact pressure of the framework's top surface and the sensor pre-pressure increase with the increase of the value of interference fit. When the value of interference fit is between 0.05 mm and 0.09 mm, roll body's inner hole surface, the framework and pressure magnetic sensitive component don't separate from each other, and the sensor works in the linear segment of characteristic curve, so the normal operation of shapemeter roll is guaranteed.
文摘外卖配取过程中实时订单的不断插入具有强烈的不确定性,需持续进行滚动优化以动态更新配取路径。动态条件下,有效地合并取餐与配送作业(dynamic order combination,DOC)可显著减少冗余路径。本文将动态配取路径规划问题转化为变长开放链滚动优化问题,并构建多目标滚动配取路径规划模型对DOC与节点排序进行集成决策。考虑滚动优化框架下紧前决策对紧后决策的调度影响,模型在兼顾配取效率和客户满意度的同时,考虑了基于look-forward的滚动调度后效性。针对该模型,本文基于NSGA-Ⅲ框架开发了多目标元启发式算法进行求解,并设计了基于插入限制规则的元胞数组解编码和混合PMX&SBX交叉方式以适应模型的复杂可行域结构。通过一系列的仿真实验,本文验证了所提出的模型和算法的有效性与优越性。
