With the help of Complex Function Mapping studied results, the analysis function of Conformal Mapping is set up. Since the complicated three dimension’s deformation problems are transferred into two dimension problem...With the help of Complex Function Mapping studied results, the analysis function of Conformal Mapping is set up. Since the complicated three dimension’s deformation problems are transferred into two dimension problems, both the stream function and strain ratio field are analyzed in the metal plastic deformation. Using the upper-bound principles, the theory of metal deformation and die cavity optimized modeling is established for random special-shaped product extrusion. As a result, this enables the realization of intelligent technique target in the die cavity of CAD/CAM integration.展开更多
Aimed at the optimal analysis and processing technology of die cavity of special-shaped products extrusion, by numerical analysis of trigonometric interpolation and Conformal Mapping theory, on the non-circle cross-se...Aimed at the optimal analysis and processing technology of die cavity of special-shaped products extrusion, by numerical analysis of trigonometric interpolation and Conformal Mapping theory, on the non-circle cross-section of special-shaped products, the conformal mapping function can be set up to translate the cross-section region into unit dish region, over numerical finite interpolation points between even and odd. Products extrusion forming can be turned into two-dimension problem, and plastic stream function can be deduced, as well as the mathematical model of the die cavity surface is established based on deferent kinds of vertical curve. By applying Upper-bound Principle, the vertical curves and related parameters of die cavity are optimized. Combining with electrical discharge machining (EDM) process and numerical control (NC) milling machine technology, the optimal processing of die cavity can be realized. Taking ellipse-shaped products as an instance, the optimal analysis and processing of die cavity including extruding experiment are carried out.展开更多
The strips U deep drawing experiments were carried out to study the effect of die cavity dimension with an extension machine manufactured by SANS company. The effects of parameters were analyzed in deep drawing proces...The strips U deep drawing experiments were carried out to study the effect of die cavity dimension with an extension machine manufactured by SANS company. The effects of parameters were analyzed in deep drawing process under different experimental conditions, such as punch load, reduction of thickness, angle of U part and surface quality. The experiment results show that the punch load increases with the decrease of female radius, and larger blank holder force enlarges the range of increasing. With the increasing of blank holder force, the angle of U part increases, and the reduction of foil thickness at the corner becomes larger. Obvious scratch and accumulation at the die cavity corner were observed by SEM. The investigation results indicate that micro U deep drawing of foil is affected by micro die cavity dimension.展开更多
Based on the car front-wheel-hub forging forming process of numerical simulation, the temperature gradient expression of forging model cavity near the surface layer was got ten, which illustrates that the forging temp...Based on the car front-wheel-hub forging forming process of numerical simulation, the temperature gradient expression of forging model cavity near the surface layer was got ten, which illustrates that the forging temperature gradient is related to forging die materials thermal conductivity, specific heat and impact speed, and the correlation coefficient is 0.97. Under the different thermal conductivity, heat capacity and forging speed, the temperature gradient was compared with each other. The paper obtained the relevant laws, which illustrates the temperature gradient relates to these three parameters in a sequence of thermal conductivity 〉 impact speed〉 specific heat capacity. To reduce thermal stress in the near-surface layer of hot forging cavity, the material with greater thermal conductivity coefficient and specific heat capacity should be used.展开更多
This study is subject to the finite element and abd uc tive network method application in the multi-cavity die. In order to select the optimal cooling system parameters to minimize the warp of a die-casting die, t he ...This study is subject to the finite element and abd uc tive network method application in the multi-cavity die. In order to select the optimal cooling system parameters to minimize the warp of a die-casting die, t he Taguchi’s method and the abductive network are used. These methods are appli ed to create an efficient model with functional nodes for the considered problem . Once the cooling system parameters are developed, this network can be used to predict the warp for the die-casting die accurately. A simulated annealing (SA) optimization algorithm with a performance index is then applied to the neur al network for searching the optimal cooling system parameters, and obtain rathe r satisfactory result as compared with the corresponding finite element veri fication.展开更多
Aimed at the modeling issues in design and quick processing of extruding die for special-shaped products, with the help of Conformal Mapping theory, Conformal Mapping function is determined by the given method of nume...Aimed at the modeling issues in design and quick processing of extruding die for special-shaped products, with the help of Conformal Mapping theory, Conformal Mapping function is determined by the given method of numerical trigonometric interpolation. Three-dimensional forming problems are transformed into two-dimensional problems, and mathematical model of die cavity surface is established based on different kinds of vertical curve, as well as the mathematical model of plastic flow in extruding deformation of special-shaped products gets completed. By upper bound method, both vertical curves of die cavity and its parameters are optimized. Combining the optimized model with the latest NC technology, NC Program of die cavity and its CAM can be realized. Taking the similar extrusion of square-shaped products with arc radius as instance, both metal plastic similar extrusion and die cavity optimization are carried out.展开更多
文摘With the help of Complex Function Mapping studied results, the analysis function of Conformal Mapping is set up. Since the complicated three dimension’s deformation problems are transferred into two dimension problems, both the stream function and strain ratio field are analyzed in the metal plastic deformation. Using the upper-bound principles, the theory of metal deformation and die cavity optimized modeling is established for random special-shaped product extrusion. As a result, this enables the realization of intelligent technique target in the die cavity of CAD/CAM integration.
基金Porject(50075076) supported by the National Natural Science Foundation of ChinaPorject(2007XM036) supported by Science and Technology of Beijing Jiaotong Uniersity, China
文摘Aimed at the optimal analysis and processing technology of die cavity of special-shaped products extrusion, by numerical analysis of trigonometric interpolation and Conformal Mapping theory, on the non-circle cross-section of special-shaped products, the conformal mapping function can be set up to translate the cross-section region into unit dish region, over numerical finite interpolation points between even and odd. Products extrusion forming can be turned into two-dimension problem, and plastic stream function can be deduced, as well as the mathematical model of the die cavity surface is established based on deferent kinds of vertical curve. By applying Upper-bound Principle, the vertical curves and related parameters of die cavity are optimized. Combining with electrical discharge machining (EDM) process and numerical control (NC) milling machine technology, the optimal processing of die cavity can be realized. Taking ellipse-shaped products as an instance, the optimal analysis and processing of die cavity including extruding experiment are carried out.
基金Projects(50835002 50805035) supported by the National Natural Science Foundation of ChinaProject(2008RFQXG041) supported by the Foundation for Innovation Scholars of Harbin, China
文摘The strips U deep drawing experiments were carried out to study the effect of die cavity dimension with an extension machine manufactured by SANS company. The effects of parameters were analyzed in deep drawing process under different experimental conditions, such as punch load, reduction of thickness, angle of U part and surface quality. The experiment results show that the punch load increases with the decrease of female radius, and larger blank holder force enlarges the range of increasing. With the increasing of blank holder force, the angle of U part increases, and the reduction of foil thickness at the corner becomes larger. Obvious scratch and accumulation at the die cavity corner were observed by SEM. The investigation results indicate that micro U deep drawing of foil is affected by micro die cavity dimension.
基金Funded by the Fundamental Research Funds for the Central University (No.2010-II-025)the National Natural Science Foundation of China(No.50675165)
文摘Based on the car front-wheel-hub forging forming process of numerical simulation, the temperature gradient expression of forging model cavity near the surface layer was got ten, which illustrates that the forging temperature gradient is related to forging die materials thermal conductivity, specific heat and impact speed, and the correlation coefficient is 0.97. Under the different thermal conductivity, heat capacity and forging speed, the temperature gradient was compared with each other. The paper obtained the relevant laws, which illustrates the temperature gradient relates to these three parameters in a sequence of thermal conductivity 〉 impact speed〉 specific heat capacity. To reduce thermal stress in the near-surface layer of hot forging cavity, the material with greater thermal conductivity coefficient and specific heat capacity should be used.
文摘This study is subject to the finite element and abd uc tive network method application in the multi-cavity die. In order to select the optimal cooling system parameters to minimize the warp of a die-casting die, t he Taguchi’s method and the abductive network are used. These methods are appli ed to create an efficient model with functional nodes for the considered problem . Once the cooling system parameters are developed, this network can be used to predict the warp for the die-casting die accurately. A simulated annealing (SA) optimization algorithm with a performance index is then applied to the neur al network for searching the optimal cooling system parameters, and obtain rathe r satisfactory result as compared with the corresponding finite element veri fication.
文摘Aimed at the modeling issues in design and quick processing of extruding die for special-shaped products, with the help of Conformal Mapping theory, Conformal Mapping function is determined by the given method of numerical trigonometric interpolation. Three-dimensional forming problems are transformed into two-dimensional problems, and mathematical model of die cavity surface is established based on different kinds of vertical curve, as well as the mathematical model of plastic flow in extruding deformation of special-shaped products gets completed. By upper bound method, both vertical curves of die cavity and its parameters are optimized. Combining the optimized model with the latest NC technology, NC Program of die cavity and its CAM can be realized. Taking the similar extrusion of square-shaped products with arc radius as instance, both metal plastic similar extrusion and die cavity optimization are carried out.
