This paper mainly focused on the growth law, model construction and visualization of a soybean root. A pot experiment was conducted in the laboratory to collect root system data and measure soybean root＇s length, dia...This paper mainly focused on the growth law, model construction and visualization of a soybean root. A pot experiment was conducted in the laboratory to collect root system data and measure soybean root＇s length, diameter and number by excavating in different periods. On the basis of an in-depth analysis of root structure geometry, we analyzed the collected experimental data with logistic equations, and got the growth of soybean root equation, according to its morphological structure characteristics of self-similarity, and discussed the virtual modeling method on the soybean root based on L-system and in Visual c＋＋ Using OpenGL technology to achieve a soybean root system topology model and visualization simulation.展开更多
Pressing process is a manufacturing method that obtained work piece with certain dimension, shape and capability through die forcing roughcast to produce plastic deformation or separate. This paper focuses on the key ...Pressing process is a manufacturing method that obtained work piece with certain dimension, shape and capability through die forcing roughcast to produce plastic deformation or separate. This paper focuses on the key problems of visualization simulation in pressing die. The final aim is that numerical simulation system can simulate the process of processing forming technique, which can supply some necessary and accurate key parameters for die design. The detail description of mechanical characteristic and key technique of sheet forming technique is discussed. Pressing forming method is one of the most important forming techniques of metal forming, which has special mechanical characteristics. The character of sheet pressing forming is that the deformation of thickness direction is very small in contrast to other directions. The deformation mode of sheet forming mainly has the following kinds: bi-directional stretch, plane stress, stretches, depths extend, bending and counter-bending. The essence of press forming is the transferring course that the transferring region of rough comes to deformation by outside force, which is main researching principle in forming and the transferring field. The analysis of pressing forming course, disclose the feature of stress-strain and their changing rule, then pressing process and forming parameters could be obtained. So the states of force and deformation of transferring region is key to determine character about the varieties of pressing transferring. The paper analyzes these factors, which may influence forming precision in pressing process. In traditional methods, some key parameter such as spring-back, bending radius for die design are calculated by experience formula or select from data table. The paper brings forward the calculation methods of key parameter in the case of drawing finite element method and numerical simulation into pressing die design. In order to calculate the value of key parameters based on data supplied by FEM, a numerical simulation application is finished combined with two descriptions of work piece deformation NURBS and discrete piece. The numerical simulation is programmed on Microsoft Visual C++ with OpenGL as the graphics tool. It establishes numerical simulation program, dynamically simulates the process of sheet pressing figuration, and gets good effects.展开更多
The implementation of a missile's visual simulation system is explained that is developed with OpenGL(open graphic library) and the flight path and flight carriage in different stages of the missile are displayed....The implementation of a missile's visual simulation system is explained that is developed with OpenGL(open graphic library) and the flight path and flight carriage in different stages of the missile are displayed. The establishment problems of the 3D scene are circumstantiated including the construction and redeployment of the model, creation of the virtual scene, setting of the multi-viewports and multi-windows etc. The missile's data driver, system flow, the modules and their mutual relations of the missile visual simulation system are discussed. The missile flight simulation results and effect of the scenes are given.展开更多
基于2000−2022年分别发表在Web of Science核心数据库和中国知网数据库的899和686篇地热数值模拟研究领域的相关文献,利用CiteSpace和VOSviewer软件进行文献计量分析,探究地热数值模拟研究发展趋势、重点研究领域与热点问题.结果显示:...基于2000−2022年分别发表在Web of Science核心数据库和中国知网数据库的899和686篇地热数值模拟研究领域的相关文献,利用CiteSpace和VOSviewer软件进行文献计量分析,探究地热数值模拟研究发展趋势、重点研究领域与热点问题.结果显示:地热数值模拟领域发文量呈指数增长,且2014年之后进入快速发展期,其中中国发文量占比最高;关键词共现和聚类时间线图谱显示重点研究方向为增强型地热系统、地源热泵、换热性能、多场耦合等.在此基础上对多场耦合过程进行总结,水-热耦合的研究起始最早且研究最多,是多场耦合的核心,可从储层物理性质和开采方式2方面出发考虑参数.三场耦合主要为水-热-力学耦合和水-热-化学耦合,在二场耦合的基础上分别加入了力学变形和地球化学反应沉淀溶解过程.其中:水-热-力学耦合是目前的研究热点;水-热-力学-化学耦合研究较少,其研究需要考虑采热过程的时间尺度效应.对主流表征裂隙的方法进行了优势和局限性的总结,离散裂隙网络模型是目前要攻坚的研究重点和热点.研究表明数值模拟方法在地热领域研究中正处于快速发展时期,是目前及未来产学研应用的重要手段.展开更多
连续刚构拱组合铁路桥是一种具有复杂结构形式和施工工序繁多的桥梁类型。为实现对该类型桥梁施工过程的全面监控和管理,以目前在建最大跨径无砟轨道高墩大跨连续刚构拱组合体系桥为背景,阐述BIM技术在该领域取得的研究成果,通过BIM技...连续刚构拱组合铁路桥是一种具有复杂结构形式和施工工序繁多的桥梁类型。为实现对该类型桥梁施工过程的全面监控和管理,以目前在建最大跨径无砟轨道高墩大跨连续刚构拱组合体系桥为背景,阐述BIM技术在该领域取得的研究成果,通过BIM技术对连续刚构拱组合梁桥进行参数化建模、施工动态模拟,以Visual Studio 2022作为开发平台开发了线形与应力监控系统,系统包含数据管理、测点设计、接口设计、模型应用等四大功能模块,对施工监控数据进行有效管理。研究结果表明:采用基于BIM数据驱动的参数化建模技术,提高了建模效率和准确性。桥梁线形数据的可视化表达简化了监控数据与设计值的对比工作,可视化模拟施工工况和动态预警提示功能为桥梁线形的发展规律分析提供参考。实现了监测数据与桥梁BIM模型的关联,方便数据存储和查找,同时可以直观地比较实测值与理论值的误差是否超限,简化了监测数据统计和对比工作。该软件系统为铁路桥梁工程的设计、施工和监测提供有力支持。展开更多
基金Supported by the Scientific Research Project of Heilongjiang Province(11551054)
文摘This paper mainly focused on the growth law, model construction and visualization of a soybean root. A pot experiment was conducted in the laboratory to collect root system data and measure soybean root＇s length, diameter and number by excavating in different periods. On the basis of an in-depth analysis of root structure geometry, we analyzed the collected experimental data with logistic equations, and got the growth of soybean root equation, according to its morphological structure characteristics of self-similarity, and discussed the virtual modeling method on the soybean root based on L-system and in Visual c＋＋ Using OpenGL technology to achieve a soybean root system topology model and visualization simulation.
文摘Pressing process is a manufacturing method that obtained work piece with certain dimension, shape and capability through die forcing roughcast to produce plastic deformation or separate. This paper focuses on the key problems of visualization simulation in pressing die. The final aim is that numerical simulation system can simulate the process of processing forming technique, which can supply some necessary and accurate key parameters for die design. The detail description of mechanical characteristic and key technique of sheet forming technique is discussed. Pressing forming method is one of the most important forming techniques of metal forming, which has special mechanical characteristics. The character of sheet pressing forming is that the deformation of thickness direction is very small in contrast to other directions. The deformation mode of sheet forming mainly has the following kinds: bi-directional stretch, plane stress, stretches, depths extend, bending and counter-bending. The essence of press forming is the transferring course that the transferring region of rough comes to deformation by outside force, which is main researching principle in forming and the transferring field. The analysis of pressing forming course, disclose the feature of stress-strain and their changing rule, then pressing process and forming parameters could be obtained. So the states of force and deformation of transferring region is key to determine character about the varieties of pressing transferring. The paper analyzes these factors, which may influence forming precision in pressing process. In traditional methods, some key parameter such as spring-back, bending radius for die design are calculated by experience formula or select from data table. The paper brings forward the calculation methods of key parameter in the case of drawing finite element method and numerical simulation into pressing die design. In order to calculate the value of key parameters based on data supplied by FEM, a numerical simulation application is finished combined with two descriptions of work piece deformation NURBS and discrete piece. The numerical simulation is programmed on Microsoft Visual C++ with OpenGL as the graphics tool. It establishes numerical simulation program, dynamically simulates the process of sheet pressing figuration, and gets good effects.
文摘The implementation of a missile's visual simulation system is explained that is developed with OpenGL(open graphic library) and the flight path and flight carriage in different stages of the missile are displayed. The establishment problems of the 3D scene are circumstantiated including the construction and redeployment of the model, creation of the virtual scene, setting of the multi-viewports and multi-windows etc. The missile's data driver, system flow, the modules and their mutual relations of the missile visual simulation system are discussed. The missile flight simulation results and effect of the scenes are given.
文摘基于2000−2022年分别发表在Web of Science核心数据库和中国知网数据库的899和686篇地热数值模拟研究领域的相关文献,利用CiteSpace和VOSviewer软件进行文献计量分析,探究地热数值模拟研究发展趋势、重点研究领域与热点问题.结果显示:地热数值模拟领域发文量呈指数增长,且2014年之后进入快速发展期,其中中国发文量占比最高;关键词共现和聚类时间线图谱显示重点研究方向为增强型地热系统、地源热泵、换热性能、多场耦合等.在此基础上对多场耦合过程进行总结,水-热耦合的研究起始最早且研究最多,是多场耦合的核心,可从储层物理性质和开采方式2方面出发考虑参数.三场耦合主要为水-热-力学耦合和水-热-化学耦合,在二场耦合的基础上分别加入了力学变形和地球化学反应沉淀溶解过程.其中:水-热-力学耦合是目前的研究热点;水-热-力学-化学耦合研究较少,其研究需要考虑采热过程的时间尺度效应.对主流表征裂隙的方法进行了优势和局限性的总结,离散裂隙网络模型是目前要攻坚的研究重点和热点.研究表明数值模拟方法在地热领域研究中正处于快速发展时期,是目前及未来产学研应用的重要手段.
文摘连续刚构拱组合铁路桥是一种具有复杂结构形式和施工工序繁多的桥梁类型。为实现对该类型桥梁施工过程的全面监控和管理,以目前在建最大跨径无砟轨道高墩大跨连续刚构拱组合体系桥为背景,阐述BIM技术在该领域取得的研究成果,通过BIM技术对连续刚构拱组合梁桥进行参数化建模、施工动态模拟,以Visual Studio 2022作为开发平台开发了线形与应力监控系统,系统包含数据管理、测点设计、接口设计、模型应用等四大功能模块,对施工监控数据进行有效管理。研究结果表明:采用基于BIM数据驱动的参数化建模技术,提高了建模效率和准确性。桥梁线形数据的可视化表达简化了监控数据与设计值的对比工作,可视化模拟施工工况和动态预警提示功能为桥梁线形的发展规律分析提供参考。实现了监测数据与桥梁BIM模型的关联,方便数据存储和查找,同时可以直观地比较实测值与理论值的误差是否超限,简化了监测数据统计和对比工作。该软件系统为铁路桥梁工程的设计、施工和监测提供有力支持。
