During the process of finite element simulation of precision warm forging, the selection of friction models has a direct effect on the precision accuracy of finite element simulation results. Among all the factors whi...During the process of finite element simulation of precision warm forging, the selection of friction models has a direct effect on the precision accuracy of finite element simulation results. Among all the factors which influence the selection of friction models, the distribution rule of normal stress at the tool-workpiece interface is a key one. To find out the distribution rule of normal stress at the tool-workpiece interface, this paper has made a systematic research on three typical plastic deformation processes: forward extrusion, backward extrusion, and lateral extrusion by a method of finite element simulation. Then on the base of synthesizing and correcting traditional friction models, a new general friction model which is fit for warm extrusion is developed at last.展开更多
Enterprise application integration （EAI） focuses on the collaboration and interconnection of various information systems, so the basic problem to be solved is how EAI guarantees that the applications will produce co...Enterprise application integration （EAI） focuses on the collaboration and interconnection of various information systems, so the basic problem to be solved is how EAI guarantees that the applications will produce consistent presentation of data, message and transaction. The metadata methodology may give us certain good ideas. First, the metadata description method of manufacturing information resource, transaction process and message delivery is put forward on the basis of operation analysis of manufacturing-oriented EAI, and then the tree-structured XML schema of corresponding object is built and a framework of metadata application in the discrete Manufacturing-Oriented EAI is established. Finally, a practical enterprise information integration system in Shanghai Tobacco Machine Co., Ltd. is presented as an example to show how it functions.展开更多
During the time of building enterprise information System （EIS）, agility of enterprise can＇ t be improved entirely just through implementing the system such as： ERP, PDM, CAPP and so on. There is an information ga...During the time of building enterprise information System （EIS）, agility of enterprise can＇ t be improved entirely just through implementing the system such as： ERP, PDM, CAPP and so on. There is an information gap between bottom rnannfacturing equipment and the top EIS, that makes against elevating the agility of enterprise. Building Web- CNC and realizing its integration with EIS is an effect way to solve this problem. The architecture of Web- CNC, the integration of Web- CNC and EIS are detailed. Lastly, an instance is analyzed and discussed.展开更多
To understand the forming behaviour of aluminum alloys, the upsetting test of aluminum alloys at evaluated temperature is conducted. Because in warm forging the flow stress decreases with increasing straining, which i...To understand the forming behaviour of aluminum alloys, the upsetting test of aluminum alloys at evaluated temperature is conducted. Because in warm forging the flow stress decreases with increasing straining, which is so-called work softening, no appropriate material formulation is available. For the evaluation of flow stress of aluminum alloys in warm forging processes, in this paper, a formula is derived by analyzing the stress data measured at various temperatures. It is demonstrated that the formula fits the flow stress obtained from experiment.展开更多
Tensile properties with different thermoforming conditions and deformation mechanism at thermoforming temperatures of automotive needlepunched carpets made up of three layers of different materials were reported.Inves...Tensile properties with different thermoforming conditions and deformation mechanism at thermoforming temperatures of automotive needlepunched carpets made up of three layers of different materials were reported.Investigations on the tensile properties were performed as a function of thermoforming temperature,extensile speed and fiber orientation based on an orthogonal experiment design.The experimental results show that the automotive carpets are rate-dependent anisotropic one and very sensitive to the forming temperature.The tensile properties are strongly depended on the forming temperature when compared with the extensile speed and the fiber orientation.Experiments only varying with the temperature were performed because of the dominative effect of the temperature.Different deformation performances were observed with different temperatures.Deformation mechanisms at the thermoforming temperatures were presented to explain the nonlinear trend of the ultimate elongation with the temperatures based on the combination of the experimental observations and the corresponding polymer theories.展开更多
A new model of roving frame FA467,which uses four frequency inverters to replace the complex mechanical transmission,is discussed.A Neuron-PID is designed to reduce the effect of various parametric variations such as ...A new model of roving frame FA467,which uses four frequency inverters to replace the complex mechanical transmission,is discussed.A Neuron-PID is designed to reduce the effect of various parametric variations such as load inertia.To ensure the constant spinning tension all over the spinning process,a feedforward controller using iterative learning control algorithm is designed to avoid disturbances caused by changes of temperature,humidity and so on.The simulation result is shown to illustrate the effectiveness of the proposed algorithm,and now the roving frame FA467 has been developed successfully.展开更多
Dear Editor, The main components of multi-view geometry and computer vision are robust pose estimation and feature matching. This letter discusses how to recover two-view geometry and match features between a pair of ...Dear Editor, The main components of multi-view geometry and computer vision are robust pose estimation and feature matching. This letter discusses how to recover two-view geometry and match features between a pair of images, and presents MCNet(a multiscale clustering network) as an algorithm for extracting multiscale features. It can identify the true inliers from the established putative correspondences, where outliers may degenerate the geometry estimation. In particular, the proposed MCNet is based on graph clustering.展开更多
In order to continuously simulate multi-pass plate rolling process,a 3-D elastic hollow-roll model was proposed and an auto mesh-refining module with data passing was developed and integrated with FE software,Marc.The...In order to continuously simulate multi-pass plate rolling process,a 3-D elastic hollow-roll model was proposed and an auto mesh-refining module with data passing was developed and integrated with FE software,Marc.The hollow-roll model has equivalent stiffness of bending resistance and deformation to the real solid and much less meshes,so the computational time is greatly reduced.Based on these,the factors influencing plate profile,such as the roll-bending force,initial crown,thermal crown and heat transfer during rolling and inter-pass cooling can be taken into account in the simulation.The auto mesh-refining module with data passing can automatically refine and re-number elements and transfer the nodal and elemental results to the new meshes.Furthermore,the 3-D modeling routine is parametrically developed and can be run independently of Marc pre-processing program.A seven-pass industrial hot rolling process was continuously simulated to validate the accuracy of model.By comparison of the calculated results with the industrial measured data,the rolling force,temperature and plate profile are in good accordance with the measured ones.展开更多
The microstractural evolution of microalloyed steel during hot forging process was investigated using physical simulation experiments. The dynamic recrystallized fraction was described by modifying Avrami＇s equation,...The microstractural evolution of microalloyed steel during hot forging process was investigated using physical simulation experiments. The dynamic recrystallized fraction was described by modifying Avrami＇s equation, the parameters of which were determined by single hit compression tests. Double hit compression tests were performed to model the equation describing the static recrystallized fraction, and the obtained predicted values were in good agreement with the measured values. Austenitic grain growth was modeled as： Dinc^5 = D0^5 ＋ 1.6 × 10^32t·exp （ -716870/RT ） using isothermal tests. Furthermore, an equation describing the dynamic recrystallized grain size was given as Ddyn=3771·Z^-0.2. The models of microstructural evolution could be applied to the numerical simulation of hot forging.展开更多
Iterations in optimization and numerical simulation for the sheet metal forming process may lead to extensive computation. In addition, uncertainties in materials or processing parameters may have great influence on t...Iterations in optimization and numerical simulation for the sheet metal forming process may lead to extensive computation. In addition, uncertainties in materials or processing parameters may have great influence on the design quality. A six sigma optimization method is proposed, by combining the dual response surface method （DRSM） and six sigma philosophy, to save computation cost and improve reliability and robustness of parts. Using this method, statistical technology, including the design of experiment and analysis of variance, approximate model and six sigma philosophy are integrated together to achieve improved quality. Two sheet metal forming processes are provided as examples to illustrate the proposed method.展开更多
文摘During the process of finite element simulation of precision warm forging, the selection of friction models has a direct effect on the precision accuracy of finite element simulation results. Among all the factors which influence the selection of friction models, the distribution rule of normal stress at the tool-workpiece interface is a key one. To find out the distribution rule of normal stress at the tool-workpiece interface, this paper has made a systematic research on three typical plastic deformation processes: forward extrusion, backward extrusion, and lateral extrusion by a method of finite element simulation. Then on the base of synthesizing and correcting traditional friction models, a new general friction model which is fit for warm extrusion is developed at last.
文摘Enterprise application integration （EAI） focuses on the collaboration and interconnection of various information systems, so the basic problem to be solved is how EAI guarantees that the applications will produce consistent presentation of data, message and transaction. The metadata methodology may give us certain good ideas. First, the metadata description method of manufacturing information resource, transaction process and message delivery is put forward on the basis of operation analysis of manufacturing-oriented EAI, and then the tree-structured XML schema of corresponding object is built and a framework of metadata application in the discrete Manufacturing-Oriented EAI is established. Finally, a practical enterprise information integration system in Shanghai Tobacco Machine Co., Ltd. is presented as an example to show how it functions.
文摘During the time of building enterprise information System （EIS）, agility of enterprise can＇ t be improved entirely just through implementing the system such as： ERP, PDM, CAPP and so on. There is an information gap between bottom rnannfacturing equipment and the top EIS, that makes against elevating the agility of enterprise. Building Web- CNC and realizing its integration with EIS is an effect way to solve this problem. The architecture of Web- CNC, the integration of Web- CNC and EIS are detailed. Lastly, an instance is analyzed and discussed.
文摘To understand the forming behaviour of aluminum alloys, the upsetting test of aluminum alloys at evaluated temperature is conducted. Because in warm forging the flow stress decreases with increasing straining, which is so-called work softening, no appropriate material formulation is available. For the evaluation of flow stress of aluminum alloys in warm forging processes, in this paper, a formula is derived by analyzing the stress data measured at various temperatures. It is demonstrated that the formula fits the flow stress obtained from experiment.
基金Supported by National Natural Science Foundation of China(No.50305020)
文摘Tensile properties with different thermoforming conditions and deformation mechanism at thermoforming temperatures of automotive needlepunched carpets made up of three layers of different materials were reported.Investigations on the tensile properties were performed as a function of thermoforming temperature,extensile speed and fiber orientation based on an orthogonal experiment design.The experimental results show that the automotive carpets are rate-dependent anisotropic one and very sensitive to the forming temperature.The tensile properties are strongly depended on the forming temperature when compared with the extensile speed and the fiber orientation.Experiments only varying with the temperature were performed because of the dominative effect of the temperature.Different deformation performances were observed with different temperatures.Deformation mechanisms at the thermoforming temperatures were presented to explain the nonlinear trend of the ultimate elongation with the temperatures based on the combination of the experimental observations and the corresponding polymer theories.
文摘A new model of roving frame FA467,which uses four frequency inverters to replace the complex mechanical transmission,is discussed.A Neuron-PID is designed to reduce the effect of various parametric variations such as load inertia.To ensure the constant spinning tension all over the spinning process,a feedforward controller using iterative learning control algorithm is designed to avoid disturbances caused by changes of temperature,humidity and so on.The simulation result is shown to illustrate the effectiveness of the proposed algorithm,and now the roving frame FA467 has been developed successfully.
基金supported by the National Natural Science Foundation of China(61703260,62173252)。
文摘Dear Editor, The main components of multi-view geometry and computer vision are robust pose estimation and feature matching. This letter discusses how to recover two-view geometry and match features between a pair of images, and presents MCNet(a multiscale clustering network) as an algorithm for extracting multiscale features. It can identify the true inliers from the established putative correspondences, where outliers may degenerate the geometry estimation. In particular, the proposed MCNet is based on graph clustering.
基金Project(51675335)supported by the National Natural Science Foundation of ChinaProject(BK20130447)supported by the Natural Science Foundation of Jiangsu Province,China
基金Project(20050248007) supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘In order to continuously simulate multi-pass plate rolling process,a 3-D elastic hollow-roll model was proposed and an auto mesh-refining module with data passing was developed and integrated with FE software,Marc.The hollow-roll model has equivalent stiffness of bending resistance and deformation to the real solid and much less meshes,so the computational time is greatly reduced.Based on these,the factors influencing plate profile,such as the roll-bending force,initial crown,thermal crown and heat transfer during rolling and inter-pass cooling can be taken into account in the simulation.The auto mesh-refining module with data passing can automatically refine and re-number elements and transfer the nodal and elemental results to the new meshes.Furthermore,the 3-D modeling routine is parametrically developed and can be run independently of Marc pre-processing program.A seven-pass industrial hot rolling process was continuously simulated to validate the accuracy of model.By comparison of the calculated results with the industrial measured data,the rolling force,temperature and plate profile are in good accordance with the measured ones.
基金This work was supported by the National Natural Science Foundation of China （No. 50275094）.
文摘The microstractural evolution of microalloyed steel during hot forging process was investigated using physical simulation experiments. The dynamic recrystallized fraction was described by modifying Avrami＇s equation, the parameters of which were determined by single hit compression tests. Double hit compression tests were performed to model the equation describing the static recrystallized fraction, and the obtained predicted values were in good agreement with the measured values. Austenitic grain growth was modeled as： Dinc^5 = D0^5 ＋ 1.6 × 10^32t·exp （ -716870/RT ） using isothermal tests. Furthermore, an equation describing the dynamic recrystallized grain size was given as Ddyn=3771·Z^-0.2. The models of microstructural evolution could be applied to the numerical simulation of hot forging.
基金This project is supported by National Natural Science Foundation of China (No.50475020).
文摘Iterations in optimization and numerical simulation for the sheet metal forming process may lead to extensive computation. In addition, uncertainties in materials or processing parameters may have great influence on the design quality. A six sigma optimization method is proposed, by combining the dual response surface method （DRSM） and six sigma philosophy, to save computation cost and improve reliability and robustness of parts. Using this method, statistical technology, including the design of experiment and analysis of variance, approximate model and six sigma philosophy are integrated together to achieve improved quality. Two sheet metal forming processes are provided as examples to illustrate the proposed method.
