Due to the unproductive and time consuming of the test cut, it is important to recognize all the possible errors before starting the process. This paper introduces a simulation program which can be used in an NC verti...Due to the unproductive and time consuming of the test cut, it is important to recognize all the possible errors before starting the process. This paper introduces a simulation program which can be used in an NC vertical milling machine. A unique method is used for simulating the cutting process and displaying the three dimensional images. This method not only simplifies greatly the treatment of the hidden line but also creates a “photograph effect” image. The program is written in Visual B.展开更多
A system architecture of solid-based NC simulation for milling machining is given, the function of which is composed of cutting simulation of different cutters, such as flat-end cutters, ball-end cutters, dome-end cut...A system architecture of solid-based NC simulation for milling machining is given, the function of which is composed of cutting simulation of different cutters, such as flat-end cutters, ball-end cutters, dome-end cutters, angle cutters and drill cutters, rapid pre-checking of interference, detection of collision, and visualization of over cut in the stock. A new method based on the design model is raised to detect the collision and pre-check the interference during NC milling machining. A special problem about the construction of a cutter′s swept volume, self-intersection is discussed. All the work on the construction, the subtraction and the display of solids is accomplished with the help of ACIS 3-D modeling.展开更多
The planning method of tool orientation in the five-axis NC machining is studied. The problem of the existing method is analyzed and a new method for generating the global smoothing tool orientation is proposed by int...The planning method of tool orientation in the five-axis NC machining is studied. The problem of the existing method is analyzed and a new method for generating the global smoothing tool orientation is proposed by introducing the key frame idea in the animation-making. According to the feature of the part, several key tool orientations are set without interference between the tool and the part. Then, these key tool orientations are inter- polated by the spline function. By mapping the surface parameter to the spline parameter, the spline function value is obtained and taken as the tool orientation when generating the CL file. The machining result shows that the proposed method realizes the global smoothing of the tool orientation and the continuity of the rotational speed and the rotational acceleration. It also avoids the shake of the machine tool and improves the machining quality.展开更多
The springback is one of the key factors which affect the forming quality of thin-walled tube NC precision bending. The elastic-plastic finite element method was proposed to study the springback process of thin-walled...The springback is one of the key factors which affect the forming quality of thin-walled tube NC precision bending. The elastic-plastic finite element method was proposed to study the springback process of thin-walled tube NC precision bending and the combination of dynamic explicit algorithm and the static implicit algorithm was proposed to solve the whole process of thin-walled tube NC precision bending. Then, the 3D elastic-plastic finite element model was established based on the DYNAFORM platform, and the model was verified to be reasonable. At last, the springback rule of thin-walled tube NC precision bending and the effect of geometry and material parameters on the springback rule of thin-walled tube NC precision bending were studied, which is useful to controlling the springback of thin-walled tube NC precision bending, and the numerical simulation method can be used to study other effect of parameters on the forming quality of thin-walled tube NC precision bending.展开更多
This paper discusses the compiling and transferring of a NC program,then,by applyingthe concept of machining scenario,presents the process of 3-dimension dynamic graphic sim-ulation based on a NC program.This techniqu...This paper discusses the compiling and transferring of a NC program,then,by applyingthe concept of machining scenario,presents the process of 3-dimension dynamic graphic sim-ulation based on a NC program.This technique can be used in the simulation of NC machin-ing process carried out on a multi-axis machining center.In the end of this paper,some opti-mization principles for tool pathes and machining parameters are put forward.展开更多
Elongation and springback are the bottleneck problems of thin-walled aluminum alloy tube NC precision bending. So thin-walled aluminum alloy tube NC precision bending based on finite element simulation is put forward....Elongation and springback are the bottleneck problems of thin-walled aluminum alloy tube NC precision bending. So thin-walled aluminum alloy tube NC precision bending based on finite element simulation is put forward. The finite element model of thin-walled aluminum alloy tube NC bending is established based on the DYNAFORM platform. The process of thin-walled aluminum alloy tube NC precision bending is simulated with the model and the elongation and springback of tube bending can be gained. A new method of measuring the elongation of thin-walled tube NC precision bending named 'pressure die measuring method' is put forward and the computing equations of bending angle, bending radius, blanking length and initial bending section based on elongation and springback angle are derived. The bending angle, bending radius, blanking length and initial bending section of tube bending can be gained with these equations based on the elongation and springback angle from the simulation. The study can be used to control the quality of thin-walled aluminum alloy tube NC bending so that precision bending without redundance can be realized.展开更多
This paper describes a dynamic simulation system for manufacturing prismatic components on machining centers named NCDSS. It is a subsystem of CAD/CAPP/NC integrated system for prismatic parts that we are working on. ...This paper describes a dynamic simulation system for manufacturing prismatic components on machining centers named NCDSS. It is a subsystem of CAD/CAPP/NC integrated system for prismatic parts that we are working on. Based on the system of CAD and CAPP, it can automati. cally generate NC program used on machining centers and can simulate the machining process in the sequence of technology. Techniques of automatically producing NC program for prismaic parts and the method of dynamic simulation are also discussed.展开更多
This paper introduces the design and Realization of NC simulation teaching system based on VB and VRML technology. The paper realize functions using the new Parallel development platform launched by Graphics Company f...This paper introduces the design and Realization of NC simulation teaching system based on VB and VRML technology. The paper realize functions using the new Parallel development platform launched by Graphics Company for VRML environment （Cortona SDK）, and uses the object oriented programming method based on ActiveX technology in the technical system. Practice has proved that the system has good stability and strong simulation function.展开更多
Java language is widely used in a variety of development platforms to develop all kinds of application software for its simple and efficient.The programming language owning platform independent is adopted to solve the...Java language is widely used in a variety of development platforms to develop all kinds of application software for its simple and efficient.The programming language owning platform independent is adopted to solve the image flicker,sound loading and other issues by the threading technology,multimedia technology,graphics and point by point comparison techniques.Dynamic real⁃time process simulation is implemented and a two⁃dimensional network of CNC machining simulation system is developed while Java applet application is as a carrier.The simulation results show that the system has a friendly interface and fast calculation speed,and platform portability has a certain practicality and application value.展开更多
This paper presents an advanced octree(AO-rep) model and an implicit formula of a generalized cutter model for five-axis milling simulation.First,the main ideal of the AO-rep model is building a hierarchical structure...This paper presents an advanced octree(AO-rep) model and an implicit formula of a generalized cutter model for five-axis milling simulation.First,the main ideal of the AO-rep model is building a hierarchical structure and representing solid volumes.The AO-rep model utilizes an octree to cull unrelated voxels,and generates a small-scale voxel model in grey octants when a cutter intersects these octants.Using a simplified intersection computation between a cube and triangles in E^3,an STL model can be converted into its AO-rep model at a preprocessing stage.Second,the authors formulate an implicit function of a generalized cutter in moving cutter frame,and determine the function in fixed workpiece frame using the theory of a rigid body motion.Finally,the authors make a simulation of machining an impeller.The result shows that the proposed approach has a high performance of time and space.展开更多
提出了一种基于STEP-NC的数控车削加工仿真系统,该仿真系统能够验证STEP-NC数控程序、模拟实际系统运行。讨论了仿真系统的译码器、基于特征的加工数据库、实体建模以及仿真驱动等组成模块实现的关键技术和方法。介绍了仿真系统的建模工...提出了一种基于STEP-NC的数控车削加工仿真系统,该仿真系统能够验证STEP-NC数控程序、模拟实际系统运行。讨论了仿真系统的译码器、基于特征的加工数据库、实体建模以及仿真驱动等组成模块实现的关键技术和方法。介绍了仿真系统的建模工具V isua l C++和O penGL。最后指出了本文研究对于STEP-NC数控加工研究的意义。展开更多
文摘Due to the unproductive and time consuming of the test cut, it is important to recognize all the possible errors before starting the process. This paper introduces a simulation program which can be used in an NC vertical milling machine. A unique method is used for simulating the cutting process and displaying the three dimensional images. This method not only simplifies greatly the treatment of the hidden line but also creates a “photograph effect” image. The program is written in Visual B.
文摘A system architecture of solid-based NC simulation for milling machining is given, the function of which is composed of cutting simulation of different cutters, such as flat-end cutters, ball-end cutters, dome-end cutters, angle cutters and drill cutters, rapid pre-checking of interference, detection of collision, and visualization of over cut in the stock. A new method based on the design model is raised to detect the collision and pre-check the interference during NC milling machining. A special problem about the construction of a cutter′s swept volume, self-intersection is discussed. All the work on the construction, the subtraction and the display of solids is accomplished with the help of ACIS 3-D modeling.
文摘The planning method of tool orientation in the five-axis NC machining is studied. The problem of the existing method is analyzed and a new method for generating the global smoothing tool orientation is proposed by introducing the key frame idea in the animation-making. According to the feature of the part, several key tool orientations are set without interference between the tool and the part. Then, these key tool orientations are inter- polated by the spline function. By mapping the surface parameter to the spline parameter, the spline function value is obtained and taken as the tool orientation when generating the CL file. The machining result shows that the proposed method realizes the global smoothing of the tool orientation and the continuity of the rotational speed and the rotational acceleration. It also avoids the shake of the machine tool and improves the machining quality.
基金Project(50225518) supported by the National Science Foundation of China for Distinguished Young Scholars Projects(50175092 59975076) supported by the National Natural Science Foundation of ChinaProject supported by the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE, PRC Project(04H53057) supported by the Aeronautical Science Foundation of China Project(Z200518) supported by the Graduate Starting Seed Fund of Northwestern Polytechnical University Project(20020699002) supported by the Specialized Research Fund for the Doctoral Program of Higher Education
文摘The springback is one of the key factors which affect the forming quality of thin-walled tube NC precision bending. The elastic-plastic finite element method was proposed to study the springback process of thin-walled tube NC precision bending and the combination of dynamic explicit algorithm and the static implicit algorithm was proposed to solve the whole process of thin-walled tube NC precision bending. Then, the 3D elastic-plastic finite element model was established based on the DYNAFORM platform, and the model was verified to be reasonable. At last, the springback rule of thin-walled tube NC precision bending and the effect of geometry and material parameters on the springback rule of thin-walled tube NC precision bending were studied, which is useful to controlling the springback of thin-walled tube NC precision bending, and the numerical simulation method can be used to study other effect of parameters on the forming quality of thin-walled tube NC precision bending.
基金the Commission of Science,Techriology and Industry for National Defence(COSTIND).
文摘This paper discusses the compiling and transferring of a NC program,then,by applyingthe concept of machining scenario,presents the process of 3-dimension dynamic graphic sim-ulation based on a NC program.This technique can be used in the simulation of NC machin-ing process carried out on a multi-axis machining center.In the end of this paper,some opti-mization principles for tool pathes and machining parameters are put forward.
基金Project (50225518) supported by the National Science Foundation of China for Distinguished Young ScholarsProject (50175092+4 种基金59975076) supported by the National Natural Science Foundation of ChinaProject supported by the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of MOE, PRCProject (04H53057) supported by the Aeronautical Science Foundation of ChinaProject (Z200518) supported by the Graduate Starting Seed Fund of Northwestern Polytechnical UniversityProject (20020699002) supported by the Specialized Research Fund for the Doctoral Program of Higher Education
文摘Elongation and springback are the bottleneck problems of thin-walled aluminum alloy tube NC precision bending. So thin-walled aluminum alloy tube NC precision bending based on finite element simulation is put forward. The finite element model of thin-walled aluminum alloy tube NC bending is established based on the DYNAFORM platform. The process of thin-walled aluminum alloy tube NC precision bending is simulated with the model and the elongation and springback of tube bending can be gained. A new method of measuring the elongation of thin-walled tube NC precision bending named 'pressure die measuring method' is put forward and the computing equations of bending angle, bending radius, blanking length and initial bending section based on elongation and springback angle are derived. The bending angle, bending radius, blanking length and initial bending section of tube bending can be gained with these equations based on the elongation and springback angle from the simulation. The study can be used to control the quality of thin-walled aluminum alloy tube NC bending so that precision bending without redundance can be realized.
文摘This paper describes a dynamic simulation system for manufacturing prismatic components on machining centers named NCDSS. It is a subsystem of CAD/CAPP/NC integrated system for prismatic parts that we are working on. Based on the system of CAD and CAPP, it can automati. cally generate NC program used on machining centers and can simulate the machining process in the sequence of technology. Techniques of automatically producing NC program for prismaic parts and the method of dynamic simulation are also discussed.
文摘This paper introduces the design and Realization of NC simulation teaching system based on VB and VRML technology. The paper realize functions using the new Parallel development platform launched by Graphics Company for VRML environment （Cortona SDK）, and uses the object oriented programming method based on ActiveX technology in the technical system. Practice has proved that the system has good stability and strong simulation function.
文摘Java language is widely used in a variety of development platforms to develop all kinds of application software for its simple and efficient.The programming language owning platform independent is adopted to solve the image flicker,sound loading and other issues by the threading technology,multimedia technology,graphics and point by point comparison techniques.Dynamic real⁃time process simulation is implemented and a two⁃dimensional network of CNC machining simulation system is developed while Java applet application is as a carrier.The simulation results show that the system has a friendly interface and fast calculation speed,and platform portability has a certain practicality and application value.
基金supported by the National Science and Technology Major Project under Grant No.2012ZX01029001-002
文摘This paper presents an advanced octree(AO-rep) model and an implicit formula of a generalized cutter model for five-axis milling simulation.First,the main ideal of the AO-rep model is building a hierarchical structure and representing solid volumes.The AO-rep model utilizes an octree to cull unrelated voxels,and generates a small-scale voxel model in grey octants when a cutter intersects these octants.Using a simplified intersection computation between a cube and triangles in E^3,an STL model can be converted into its AO-rep model at a preprocessing stage.Second,the authors formulate an implicit function of a generalized cutter in moving cutter frame,and determine the function in fixed workpiece frame using the theory of a rigid body motion.Finally,the authors make a simulation of machining an impeller.The result shows that the proposed approach has a high performance of time and space.
文摘提出了一种基于STEP-NC的数控车削加工仿真系统,该仿真系统能够验证STEP-NC数控程序、模拟实际系统运行。讨论了仿真系统的译码器、基于特征的加工数据库、实体建模以及仿真驱动等组成模块实现的关键技术和方法。介绍了仿真系统的建模工具V isua l C++和O penGL。最后指出了本文研究对于STEP-NC数控加工研究的意义。
