By using the Finite Element Inverse Approach based on the Hill quadratic anisotrop-ically yield criterion and the quadrilateral element, a fast analyzing software-FASTAMP for the sheet metal forming is developed. The ...By using the Finite Element Inverse Approach based on the Hill quadratic anisotrop-ically yield criterion and the quadrilateral element, a fast analyzing software-FASTAMP for the sheet metal forming is developed. The blank shapes of three typical stampings are simulated and compared with numerical results given by the AUTOFORM software and experimental results, respectively. The comparison shows that the FASTAMP can predict blank shape and strain distribution of the stamping more precisely and quickly than those given by the traditional methods and the AUTOFORM.展开更多
The forming principle and deformation analysis of NC incremental sheet metalforming process as well as the process planning, experiment and key process parameters of verticalwall square box forming are presented. Beca...The forming principle and deformation analysis of NC incremental sheet metalforming process as well as the process planning, experiment and key process parameters of verticalwall square box forming are presented. Because the deformation of sheet metal only occurs around thetool head and the deformed region is subjected to stretch deformation, the deformed region of sheetmetal thins, and surface area increases. Sheet metal forming stepwise is to lead to the whole sheetmetal deformation. The forming half-apex angle 9 and corner radius R are the main processparameters in NC incremental forming of vertical wall square box. According to sine law, a verticalwall square box can't be formed by NC incremental sheet metal forming process in a single process,rather, it must be formed in multi processes. Thus, the parallel line type tool path process methodis presented to form the vertical wall square box, and the experiment and analysis are made toverify it.展开更多
How to directly fabricate metallic functional parts with selective laser sintering (SLS) process is a potential technique that scientists are researching. Existent problems during directly fabricating metal part by us...How to directly fabricate metallic functional parts with selective laser sintering (SLS) process is a potential technique that scientists are researching. Existent problems during directly fabricating metal part by use of SLS are analyzed. For the sake of solving the problems, a new idea of adding self-propagating high-temperature synthesis (SHS) material into metallic powder material to form new type of SLS metallic powder material is put forward. This powder material can release controllable amount of heat during its interaction with the laser beam energy to reduce the requirement to laser power during directly sintering metallic part, to prolong the time of metallic liquid phase existing, and to improve the intensity and accuracy of SLS part. For this reason, SHS material′s interaction with the CO2 laser beam energy is researched, which proves that CO2 laser beam energy may instantly ignite SHS reaction. On the basis of the above-mentioned researches, the effect of sintering the metal powder material mixing SHS material with CO2 laser is also researched, which shows: there is an optimal blending ratio of various material in the new metallic powder material. Under the optimal blending ratio and SLS process parameters, this new metallic powder material can indeed release amount of heat and SHS reaction may be controlled within the laser sintering. This research result makes it possible that the metallic part is directly sintered with small CO2 laser (less than 50W), which may greatly reduce the volume, cost and running expenditure of SLS machine, be propitious to application.展开更多
The design of the cooling system of injection molds directly affects both productivity and the quality of the final part. Using the cooling process CAE system to instruct the mold design, the efficiency and quality ...The design of the cooling system of injection molds directly affects both productivity and the quality of the final part. Using the cooling process CAE system to instruct the mold design, the efficiency and quality of design can be improved greatly. At the same time, it is helpful to confirm the cooling system structure and optimize the process conditions. In this paper, the 3D surface model of mold cavity is used to replace the middle-plane model in the simulation by Boundary Element Method, which break the bottleneck of the application of the injection molding simulation softwares base on the middle-plane model. With the improvements of this paper, a practical and commercial simulation software of injection molding cooling process named as HsCAE3D6.0 is developed.展开更多
In a one-of-a-kind and order-orient ed production corporation, job shop scheduling plays an important role in the prod uction planning system and production process control. Since resource selection in job shop sche...In a one-of-a-kind and order-orient ed production corporation, job shop scheduling plays an important role in the prod uction planning system and production process control. Since resource selection in job shop scheduling directly influences the qualities and due dates of produc ts and production cost, it is indispensable to take resource selection into acco unt during job shop scheduling. By analyzing the relative characteristics of res ources, an approach of fuzzy decision is proposed for resource selection. Finall y, issues in the application of the approach are discussed.展开更多
基金Project supported by the National Natural Sciences Foundation of China(No. 50335060).
文摘By using the Finite Element Inverse Approach based on the Hill quadratic anisotrop-ically yield criterion and the quadrilateral element, a fast analyzing software-FASTAMP for the sheet metal forming is developed. The blank shapes of three typical stampings are simulated and compared with numerical results given by the AUTOFORM software and experimental results, respectively. The comparison shows that the FASTAMP can predict blank shape and strain distribution of the stamping more precisely and quickly than those given by the traditional methods and the AUTOFORM.
基金This project is supported by National Natural Science Foundation of China (No.50175034).
文摘The forming principle and deformation analysis of NC incremental sheet metalforming process as well as the process planning, experiment and key process parameters of verticalwall square box forming are presented. Because the deformation of sheet metal only occurs around thetool head and the deformed region is subjected to stretch deformation, the deformed region of sheetmetal thins, and surface area increases. Sheet metal forming stepwise is to lead to the whole sheetmetal deformation. The forming half-apex angle 9 and corner radius R are the main processparameters in NC incremental forming of vertical wall square box. According to sine law, a verticalwall square box can't be formed by NC incremental sheet metal forming process in a single process,rather, it must be formed in multi processes. Thus, the parallel line type tool path process methodis presented to form the vertical wall square box, and the experiment and analysis are made toverify it.
文摘How to directly fabricate metallic functional parts with selective laser sintering (SLS) process is a potential technique that scientists are researching. Existent problems during directly fabricating metal part by use of SLS are analyzed. For the sake of solving the problems, a new idea of adding self-propagating high-temperature synthesis (SHS) material into metallic powder material to form new type of SLS metallic powder material is put forward. This powder material can release controllable amount of heat during its interaction with the laser beam energy to reduce the requirement to laser power during directly sintering metallic part, to prolong the time of metallic liquid phase existing, and to improve the intensity and accuracy of SLS part. For this reason, SHS material′s interaction with the CO2 laser beam energy is researched, which proves that CO2 laser beam energy may instantly ignite SHS reaction. On the basis of the above-mentioned researches, the effect of sintering the metal powder material mixing SHS material with CO2 laser is also researched, which shows: there is an optimal blending ratio of various material in the new metallic powder material. Under the optimal blending ratio and SLS process parameters, this new metallic powder material can indeed release amount of heat and SHS reaction may be controlled within the laser sintering. This research result makes it possible that the metallic part is directly sintered with small CO2 laser (less than 50W), which may greatly reduce the volume, cost and running expenditure of SLS machine, be propitious to application.
基金Supported by NationalNatural Science FoundationCouncil of the People’s Republic of China (20490224)
文摘The design of the cooling system of injection molds directly affects both productivity and the quality of the final part. Using the cooling process CAE system to instruct the mold design, the efficiency and quality of design can be improved greatly. At the same time, it is helpful to confirm the cooling system structure and optimize the process conditions. In this paper, the 3D surface model of mold cavity is used to replace the middle-plane model in the simulation by Boundary Element Method, which break the bottleneck of the application of the injection molding simulation softwares base on the middle-plane model. With the improvements of this paper, a practical and commercial simulation software of injection molding cooling process named as HsCAE3D6.0 is developed.
文摘In a one-of-a-kind and order-orient ed production corporation, job shop scheduling plays an important role in the prod uction planning system and production process control. Since resource selection in job shop scheduling directly influences the qualities and due dates of produc ts and production cost, it is indispensable to take resource selection into acco unt during job shop scheduling. By analyzing the relative characteristics of res ources, an approach of fuzzy decision is proposed for resource selection. Finall y, issues in the application of the approach are discussed.
