组合玉米和组合超球颗粒模型的三维离散元法算法研究
|
摘要
本文在课题组已开发的三维离散元仿真软件的基础上,增加了三维玉米颗粒和超球颗粒两个重要的颗粒模型。三维玉米颗粒模型采用球颗粒组合的方法来进行颗粒建模,文中对组合玉米颗粒的建模方法、颗粒之间以及颗粒和边界之间的离散元算法都进行了详细的说明,并进行了详细的软件设计,包括需求分析、系统构架、各个功能模块的实现说明,最后通过试验对比来验证三维组合玉米颗粒模块在已有的三维离散元软件中的可行性。鉴于组合玉米颗粒模型的成功实现,对超球颗粒根据自身的特性来进行组合球建模,并进行了软件实现。
三维组合玉米颗粒和超球颗粒模块的实现,扩大了课题组的三维离散元仿真软件的适用范围,对于推动该软件的实际应用具有一定意义。
With the growing of population and improving of living standards, the world takes more and more attention to agriculture, production efficiency of agricultural directly affects the people's standard of living. The rapid development of industry has promoted the modernization and mechanization of agricultural production, greatly enhanced the efficiency of agricultural production. At present, the development of new agricultural machinery products need to prototype design, prototype, test, modify the design and repeat the tedious process of trial and experimentation, this process need to take a long time to shape products and put into production.
With the rapid development of the computer technology and numerical simulation methods,American scholar, Cundall Professor, presented a numerical simulation method of Analysis of discrete process of physical movement– DEM, in 1971, providing a new solution to study the dynamic complex behavior of objects. As the superiority of DEM in the analysis of discrete physical, it has become a numerical simulation method in an efficient, rich in prospects for the development to solve the problem of non-continuous medium mechanics, in recent years. DEM is widely used in mining engineering, structural engineering, geotechnical engineering, material flow, materials, mechanics and engineering geology and other fields. After the nineties, with the rapid development in foreign countries of DEM, a variety of discrete element commercial software has emerged. U.S. ITASCA developed and refined the UDEC and 3DEC procedures based on the irregular shaped block unit, and the PFC2D and PFC3D software based on the disc-shaped and spherical discrete units. In particular, PFC2D and PFC3D software, A result of a neighbor cell search fast and efficient simulation of large deformation, etc., has been widely applied in many areas, so that DEM in engineering a major step forward.
If the DEM and the design of agricultural machinery was combined, we can make the design of agricultural machinery have a work-in-process simulation, this can solve the agricultural machinery design, prototype, test, modify the design of the cumbersome process, save a lot of manpower, material and financial resources, for the promoting the early realization of China's agricultural mechanization, it has positive significance.
The corn is China's second largest grain varieties, having extensive use of the value of involving the planting, breeding, food, chemical, pharmaceutical and other industries. Therefore, researching corn particle model has important significance for agricultural production. At present the research about the corn particles DEM modeling at home and abroad is relatively small. In 2009, coetzee set up the corn particle DEM analysis model of corn particle using balls combinations method. The corn model ,using two different radius of the ball through a fixed position as a whole, represents a three-dimensional model of corn . This methods can be roughly expressed corn particles, but there are some disadvantages,such as deviation and poor flexibility. One of the main work of this paper is to build a relatively precision and flexibility DEM corn model。
Combination particle model method provides a technology to simulate irregular particles or irregular blocks. The basic idea is that a number of particles form a particle unit through a combination of a fixed spatial structure. In this article, three-dimensional corn grain is modeled by using combination particle model method. Three-dimensional geometric modeling of corn grain is detailedly described by graphics and algorithms and the corn grain generation method is discussed. The generation conditions in the discharge port are analyzed to make sure that corn grains have been generated are correct. The implementations of several important functions of the simulation software are introduced. The neighbor search of corn grain,valuation distribution, the normal distribution and uniform distribution of the particle sizes,the simulation process between a corn and another corn, a corn and a boundary, the method of how to save the results of simulation are included. It also introduces several important functions of demonstration and performance analysis module in the DEM software of the three-dimensional corn grain, such as normal presentation, showing the number and the speed of a particle, tracking a particle, showing the sports curves about various physical quantities of tracked particles in a period of time or in the whole simulation process.
Based on the research of DEM algorithms about three-dimensional combination corn, the writer uses object-oriented modeling to analyses three-dimensional DEM simulation software, including system requirements analysis, the function modules, architecture design and the specific processes ,gives the system's class diagram and flow chart ,having laid the foundation for the DEM simulation software about
three-dimensional combination corn . The advantages of the particle model the expressed by super-ball equation as (f x y z =∑= axε? =can simulate the particle shape of more than 60% of natural existence Approximately. To study the super-sphere particle model discrete element method, it will be have a certain significance of the development of DEM. In view of the well-form of the procedure and simulation results of Three-dimensional combination of corn particles, this paper adopts the method of combination of ball particles to achieve the super-ball particles in discrete element method simulation. First, display the super-ball contour model in a powerful mapping tool for PRO / E with the marking key points of methods, then, set the position of each combination ball in the ultra-ball contour model by using the PRO / E; Finally store the parameters information of the super-ball and the information for each combination of balls in the database. When the three-dimensional discrete element simulation software requires super-particle model, the calculation on the discrete element simulation can be done only by reading the data from the database.
Using a combination of black box testing and white box testing methods, this paper has been done the test of system, include modules of the corn grain front module test, particulate calculation module test, simulation module testing, performance analysis module test . During the process of testing, Problems was discovered continuously, procedure was also optimized continuously .
This paper proves the reasonable of the software simulation, based on the three-dimensional discrete element simulation software simulation of corn particle model, by comparing and verifying the way of through the test of the simulation results, the kinds of odd and even row of the rate of seed tilt angle, seed and other aspects.
In summary, on the basis of the developed three-dimensional discrete element simulation software by the research group, this article adds two important functional modules of three-dimensional combination of corn grain and super-ball, and expands the scope of application of the discrete element of the development, which is essential in the promoting of DEM and the realization of China's agricultural mechanization especially.
三维组合玉米颗粒和超球颗粒模块的实现,扩大了课题组的三维离散元仿真软件的适用范围,对于推动该软件的实际应用具有一定意义。
With the growing of population and improving of living standards, the world takes more and more attention to agriculture, production efficiency of agricultural directly affects the people's standard of living. The rapid development of industry has promoted the modernization and mechanization of agricultural production, greatly enhanced the efficiency of agricultural production. At present, the development of new agricultural machinery products need to prototype design, prototype, test, modify the design and repeat the tedious process of trial and experimentation, this process need to take a long time to shape products and put into production.
With the rapid development of the computer technology and numerical simulation methods,American scholar, Cundall Professor, presented a numerical simulation method of Analysis of discrete process of physical movement– DEM, in 1971, providing a new solution to study the dynamic complex behavior of objects. As the superiority of DEM in the analysis of discrete physical, it has become a numerical simulation method in an efficient, rich in prospects for the development to solve the problem of non-continuous medium mechanics, in recent years. DEM is widely used in mining engineering, structural engineering, geotechnical engineering, material flow, materials, mechanics and engineering geology and other fields. After the nineties, with the rapid development in foreign countries of DEM, a variety of discrete element commercial software has emerged. U.S. ITASCA developed and refined the UDEC and 3DEC procedures based on the irregular shaped block unit, and the PFC2D and PFC3D software based on the disc-shaped and spherical discrete units. In particular, PFC2D and PFC3D software, A result of a neighbor cell search fast and efficient simulation of large deformation, etc., has been widely applied in many areas, so that DEM in engineering a major step forward.
If the DEM and the design of agricultural machinery was combined, we can make the design of agricultural machinery have a work-in-process simulation, this can solve the agricultural machinery design, prototype, test, modify the design of the cumbersome process, save a lot of manpower, material and financial resources, for the promoting the early realization of China's agricultural mechanization, it has positive significance.
The corn is China's second largest grain varieties, having extensive use of the value of involving the planting, breeding, food, chemical, pharmaceutical and other industries. Therefore, researching corn particle model has important significance for agricultural production. At present the research about the corn particles DEM modeling at home and abroad is relatively small. In 2009, coetzee set up the corn particle DEM analysis model of corn particle using balls combinations method. The corn model ,using two different radius of the ball through a fixed position as a whole, represents a three-dimensional model of corn . This methods can be roughly expressed corn particles, but there are some disadvantages,such as deviation and poor flexibility. One of the main work of this paper is to build a relatively precision and flexibility DEM corn model。
Combination particle model method provides a technology to simulate irregular particles or irregular blocks. The basic idea is that a number of particles form a particle unit through a combination of a fixed spatial structure. In this article, three-dimensional corn grain is modeled by using combination particle model method. Three-dimensional geometric modeling of corn grain is detailedly described by graphics and algorithms and the corn grain generation method is discussed. The generation conditions in the discharge port are analyzed to make sure that corn grains have been generated are correct. The implementations of several important functions of the simulation software are introduced. The neighbor search of corn grain,valuation distribution, the normal distribution and uniform distribution of the particle sizes,the simulation process between a corn and another corn, a corn and a boundary, the method of how to save the results of simulation are included. It also introduces several important functions of demonstration and performance analysis module in the DEM software of the three-dimensional corn grain, such as normal presentation, showing the number and the speed of a particle, tracking a particle, showing the sports curves about various physical quantities of tracked particles in a period of time or in the whole simulation process.
Based on the research of DEM algorithms about three-dimensional combination corn, the writer uses object-oriented modeling to analyses three-dimensional DEM simulation software, including system requirements analysis, the function modules, architecture design and the specific processes ,gives the system's class diagram and flow chart ,having laid the foundation for the DEM simulation software about
three-dimensional combination corn . The advantages of the particle model the expressed by super-ball equation as (f x y z =∑= axε? =can simulate the particle shape of more than 60% of natural existence Approximately. To study the super-sphere particle model discrete element method, it will be have a certain significance of the development of DEM. In view of the well-form of the procedure and simulation results of Three-dimensional combination of corn particles, this paper adopts the method of combination of ball particles to achieve the super-ball particles in discrete element method simulation. First, display the super-ball contour model in a powerful mapping tool for PRO / E with the marking key points of methods, then, set the position of each combination ball in the ultra-ball contour model by using the PRO / E; Finally store the parameters information of the super-ball and the information for each combination of balls in the database. When the three-dimensional discrete element simulation software requires super-particle model, the calculation on the discrete element simulation can be done only by reading the data from the database.
Using a combination of black box testing and white box testing methods, this paper has been done the test of system, include modules of the corn grain front module test, particulate calculation module test, simulation module testing, performance analysis module test . During the process of testing, Problems was discovered continuously, procedure was also optimized continuously .
This paper proves the reasonable of the software simulation, based on the three-dimensional discrete element simulation software simulation of corn particle model, by comparing and verifying the way of through the test of the simulation results, the kinds of odd and even row of the rate of seed tilt angle, seed and other aspects.
In summary, on the basis of the developed three-dimensional discrete element simulation software by the research group, this article adds two important functional modules of three-dimensional combination of corn grain and super-ball, and expands the scope of application of the discrete element of the development, which is essential in the promoting of DEM and the realization of China's agricultural mechanization especially.
引文
[1]张锐.基于离散元细观分析的土壤动态行为研究[D].吉林大学, 2005.
[2]刘凯欣,高凌天.离散元法研究的评述[J].力学进展, 2003, 33(4): 483-490.
[3]吴剑.滑带剪切过程的离散元模拟研究[D].中国科学院, 2007.
[4]武锦涛,陈纪忠,阳永荣.模拟颗粒流动的离散元方法及其应用[J].现代化工, 2003, 23(4): 56-58.
[5] Cundall P A, Strack O L. A discrete numerical model for granular assembles[J]. Geotechnique, 1979, 29(1): 47-65.
[6] Fleissner F, Gaugele T, Eberhard P. Applications of the discrete element method in mechanical engineering[J].Multibody Syst.Dyn, 2007, 18: 81–94.
[7] Cundall P A, Strack O L. Particle flow code in 2-dimensions[R]. Itasca Consulting Group, Inc, 1999: 15-18.
[8] Cundall P A, Hart R D.Development of generalized 2-D and 3-D discrete element programs for modeling jointed rock[R].ITASCA Consulting Group, Misc. Paper SL28521, U. S. Army Corps of Engineers, 1985: 221-223.
[9]徐泳,李艳洁,李红艳.离散元法在农业机械化中应用评述[J].农机化研究, 2004(5): 26-30.
[10]于建群,付宏,李红等.离散元法及其在农业机械工作部件研究与设计中的应用[J].农业工程学报, 2005, 21(5): 1-6.
[11] Kuo H P, Knight P C,Parker D J.The influence of DEM simulation parameters on the particle behavior in a V-mixer[J]. Chemical Engineering Science, 2002, 57: 3621-3638.
[12] Lin X, Ng T T. Contact detection algorithms for three-dimensional ellipsoids indiscrete element modeling[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 1995, 19: 653-659.
[13] Muguruma Y, Tanaka T, Tsuji Y. Numerical simulation of particulate flow with liquid bridge between particles (simulation of centrifugal tumbling granulator) [J]. Powder Technology, 2000, 109: 49-57.
[14] Sawamoto Y, Tsuboto H, Kasai Y, et al. Analytical studies on local damage toreinforced concrete structures under impact loading by discrete element method[J]. Nuclear Engineering and Design, 1998, 179: 157-177.
[15] Coetzee C J.Calibration of granular material parameters for DEM modelling and numerical verification by blade-granular material interaction[J]. Jounal of Terramechanics 2009, 46: 15-26
[16] Cook F. DEC news and world report[R]. Official Publication of the UDEC Users Group, ITASCA Consulting Group, Inc, 1985.
[17]王泳嘉,刘连峰.三维离散单元法软件系统TRHDEC的研制[J].岩石力学与工程学报, 1996, 15: 200-210.
[18]王泳嘉,宋文洲,赵艳娟.离散元法软件系统2D-block的现代化特点[J].岩石力学与工程学报, 2000, 6(增刊): 1057-1060.
[19] Kozicki.A new open-source software developed for numerical simulations using discrete modeling methods Comput[J]. Methods Appl. Mech. Engrg. 2008, 197: 4429-4443.
[20] Kruggel E. A study on the validity of the multi sphere Discrete Element Method[J]. Powder Technology 2008, 188: 153-165.
[21] Algis D. An approach to simulate the motion of sphericaland non-spherical fuel particles in combustion chambers[J]. Granular Matter 3: 231-265.
[22] Bertrand. DEM-based models for the mixing of granular materials[J]. Chemical Engineering Science 2005, 60: 2517-2531.
[23] Langston.P A. Distinct element modelling of non-spherical frictionless particle flow[J]. Chemical Engineering Science 2004, 59: 425-435.
[24] Bernhard P. Numerical simulation of the motion of granular material using object-oriented techniques[J]. Comput. Methods Appl. Mech. Engrg. 2002, 191: 1983-2007.
[25] Asmar B N. Validation tests on a distinct element model of vibrating cohesive particle systems[J]. Computers and Chemical Engineering 2002, 26: 785-802.
[26] Feras Y. Fraige.Distinct element modelling of cubic particle packing and flow[J]. Powder Technology 2008, 186: 224-240.
[27] Antony S J, Ghadiri M. Size effects in a slowly sheared granular media[J]. Journal of Applied Mechanics-Trasactions of the ASME 2001, 68(5): 772-775.
[28]贾志刚.精通OpenGL[M].北京:电子工业出版社, 1998: 23-38.
[29]李微,徐国标. OpenGL 3D入门与提高[M].西安:西南交通大学出版社, 1998: 98-120.
[30]江早,王洪成. OpenGL VC/VB图形编程[M].北京:科学出版社, 2001: 36-40.
[31]白燕斌等. OpenGL三维图形库编程指南[M].北京:机械工业出版社, 1998: 112-150.
[32]孙波. OpenGL编程实例学习教程[M].北京:北京大学出版社, 2000: 51-80.
[33]曹自洋,郝矿荣.基于MFC的OpenGL动态仿真技术[J].电脑开发与应用, 2003, 16(12): 29-30.
[34]匡天君,滕远道,王乘,徐明毅.基于MFC和OpenGL三维图形的开发[J].微计算机信息, 2004, 20(6): 115-116.
[35]钟元. Pro/E调用MFC对话框技术[M].北京:机械工业出版社, 2003 : 50-52.
[36]夏继海. Pro/Engineer行为建模技术在钣金件设计中的应用[J].数字化设计, 2002, 7: 66-68.
[37] Parametric Technology Corporation. Pro/Toolkit User’s Guide[J]. USA PTC 2004: 1-45.
[38] Luis Soiano Pere Brunet. Constructive Constraint-based Model for Parametric CAD Systems[J]. Computer Aided Design, 2000, 8: 34-36.
[39]林清安. Pro/ENGINEER2001钣金设计[M].北京:清华大学出版社, 2003:110-136.
[40]李世国. Pro/TOOLKIT程序设计[M].北京:机械工业出版社, 2003: 50-80.
[41]张继春. Pro/ENGINEER二次开发实用教程[M].北京:北京大学出版社, 2003: 42-62.
[42]蒋家东,张福润,杨楚民.实用Pro/ENGINEER二次开发技术自动建模研究[J].计算机应用研究, 2003, 4: 75-77.
[43]肖颖,童水光,陈敏,杨美原.基于Visual C++的Pro/E三维标准库开发研究[J].机械工程师, 2001, 11: 22-24.
[2]刘凯欣,高凌天.离散元法研究的评述[J].力学进展, 2003, 33(4): 483-490.
[3]吴剑.滑带剪切过程的离散元模拟研究[D].中国科学院, 2007.
[4]武锦涛,陈纪忠,阳永荣.模拟颗粒流动的离散元方法及其应用[J].现代化工, 2003, 23(4): 56-58.
[5] Cundall P A, Strack O L. A discrete numerical model for granular assembles[J]. Geotechnique, 1979, 29(1): 47-65.
[6] Fleissner F, Gaugele T, Eberhard P. Applications of the discrete element method in mechanical engineering[J].Multibody Syst.Dyn, 2007, 18: 81–94.
[7] Cundall P A, Strack O L. Particle flow code in 2-dimensions[R]. Itasca Consulting Group, Inc, 1999: 15-18.
[8] Cundall P A, Hart R D.Development of generalized 2-D and 3-D discrete element programs for modeling jointed rock[R].ITASCA Consulting Group, Misc. Paper SL28521, U. S. Army Corps of Engineers, 1985: 221-223.
[9]徐泳,李艳洁,李红艳.离散元法在农业机械化中应用评述[J].农机化研究, 2004(5): 26-30.
[10]于建群,付宏,李红等.离散元法及其在农业机械工作部件研究与设计中的应用[J].农业工程学报, 2005, 21(5): 1-6.
[11] Kuo H P, Knight P C,Parker D J.The influence of DEM simulation parameters on the particle behavior in a V-mixer[J]. Chemical Engineering Science, 2002, 57: 3621-3638.
[12] Lin X, Ng T T. Contact detection algorithms for three-dimensional ellipsoids indiscrete element modeling[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 1995, 19: 653-659.
[13] Muguruma Y, Tanaka T, Tsuji Y. Numerical simulation of particulate flow with liquid bridge between particles (simulation of centrifugal tumbling granulator) [J]. Powder Technology, 2000, 109: 49-57.
[14] Sawamoto Y, Tsuboto H, Kasai Y, et al. Analytical studies on local damage toreinforced concrete structures under impact loading by discrete element method[J]. Nuclear Engineering and Design, 1998, 179: 157-177.
[15] Coetzee C J.Calibration of granular material parameters for DEM modelling and numerical verification by blade-granular material interaction[J]. Jounal of Terramechanics 2009, 46: 15-26
[16] Cook F. DEC news and world report[R]. Official Publication of the UDEC Users Group, ITASCA Consulting Group, Inc, 1985.
[17]王泳嘉,刘连峰.三维离散单元法软件系统TRHDEC的研制[J].岩石力学与工程学报, 1996, 15: 200-210.
[18]王泳嘉,宋文洲,赵艳娟.离散元法软件系统2D-block的现代化特点[J].岩石力学与工程学报, 2000, 6(增刊): 1057-1060.
[19] Kozicki.A new open-source software developed for numerical simulations using discrete modeling methods Comput[J]. Methods Appl. Mech. Engrg. 2008, 197: 4429-4443.
[20] Kruggel E. A study on the validity of the multi sphere Discrete Element Method[J]. Powder Technology 2008, 188: 153-165.
[21] Algis D. An approach to simulate the motion of sphericaland non-spherical fuel particles in combustion chambers[J]. Granular Matter 3: 231-265.
[22] Bertrand. DEM-based models for the mixing of granular materials[J]. Chemical Engineering Science 2005, 60: 2517-2531.
[23] Langston.P A. Distinct element modelling of non-spherical frictionless particle flow[J]. Chemical Engineering Science 2004, 59: 425-435.
[24] Bernhard P. Numerical simulation of the motion of granular material using object-oriented techniques[J]. Comput. Methods Appl. Mech. Engrg. 2002, 191: 1983-2007.
[25] Asmar B N. Validation tests on a distinct element model of vibrating cohesive particle systems[J]. Computers and Chemical Engineering 2002, 26: 785-802.
[26] Feras Y. Fraige.Distinct element modelling of cubic particle packing and flow[J]. Powder Technology 2008, 186: 224-240.
[27] Antony S J, Ghadiri M. Size effects in a slowly sheared granular media[J]. Journal of Applied Mechanics-Trasactions of the ASME 2001, 68(5): 772-775.
[28]贾志刚.精通OpenGL[M].北京:电子工业出版社, 1998: 23-38.
[29]李微,徐国标. OpenGL 3D入门与提高[M].西安:西南交通大学出版社, 1998: 98-120.
[30]江早,王洪成. OpenGL VC/VB图形编程[M].北京:科学出版社, 2001: 36-40.
[31]白燕斌等. OpenGL三维图形库编程指南[M].北京:机械工业出版社, 1998: 112-150.
[32]孙波. OpenGL编程实例学习教程[M].北京:北京大学出版社, 2000: 51-80.
[33]曹自洋,郝矿荣.基于MFC的OpenGL动态仿真技术[J].电脑开发与应用, 2003, 16(12): 29-30.
[34]匡天君,滕远道,王乘,徐明毅.基于MFC和OpenGL三维图形的开发[J].微计算机信息, 2004, 20(6): 115-116.
[35]钟元. Pro/E调用MFC对话框技术[M].北京:机械工业出版社, 2003 : 50-52.
[36]夏继海. Pro/Engineer行为建模技术在钣金件设计中的应用[J].数字化设计, 2002, 7: 66-68.
[37] Parametric Technology Corporation. Pro/Toolkit User’s Guide[J]. USA PTC 2004: 1-45.
[38] Luis Soiano Pere Brunet. Constructive Constraint-based Model for Parametric CAD Systems[J]. Computer Aided Design, 2000, 8: 34-36.
[39]林清安. Pro/ENGINEER2001钣金设计[M].北京:清华大学出版社, 2003:110-136.
[40]李世国. Pro/TOOLKIT程序设计[M].北京:机械工业出版社, 2003: 50-80.
[41]张继春. Pro/ENGINEER二次开发实用教程[M].北京:北京大学出版社, 2003: 42-62.
[42]蒋家东,张福润,杨楚民.实用Pro/ENGINEER二次开发技术自动建模研究[J].计算机应用研究, 2003, 4: 75-77.
[43]肖颖,童水光,陈敏,杨美原.基于Visual C++的Pro/E三维标准库开发研究[J].机械工程师, 2001, 11: 22-24.