Three-Dimensional Simulations of RESET Operation in Phase-Change Random Access Memory with Blade-Type Like Phase Change Layer by Finite Element Modeling

An optimized device structure for reducing the RESET current of phase-change random access memory （PCRAM） with blade-type like （BTL） phase change layer is proposed. The electrical thermal analysis of the BTL cell and the blade heater contactor structure by three-dimensional finite element modeling are compared with each other during RESET operation. The simulation results show that the programming region of the phase change layer in the BTL cell is much smaller, and thermal electrical distributions of the BTL cell are more concentrated on the TiN/GST interface. The results indicate that the BTL cell has the superiorities of increasing the heating efficiency, decreasing the power consumption and reducing the RESET current from 0.67mA to 0.32mA. Therefore, the BTL cell will be appropriate for high performance PCRAM device with lower power consumption and lower RESET current.

Research on the Three-dimensional Modeling and Optimization of a Virtual Tower Crane Based on 3DS Max, Solidworks and EON Professional

Three-dimensional modeling of virtual hoisting machinery is the critical works to structure the system of virtual construction, and the foundation to realize intelligent and interactive virtual hoisting. Aimed at enhancing the requests of image quality and stability of the virtual construction scene, taking a tower crane for example. We studied the technology of three-dimensional modeling and optimization of a virtual tower crane, and a method named two-stage model optimization was put forward. This depended on the modeling stage using Solidworks and 3DS Max and the performance optimization stage in EON. The practice of software development indicates that the proposed methods of three-dimensional modeling and optimization could satisfy the performance request of virtual construction system and be popularized to other virtual system.

Simulation-Based Construction of Three-Dimensional Process Model for Punching Cartridge Cases

A method of constructing three-dimensional process model for the punching cartridge cases is presented based on DEFORM simulation analysis. Using DEFORM software,the finite element simulation models for the punching and forming process of cartridge cases are established,and the corresponding simulation result model of each intermediate procedure is obtained by continuously performing the forming process simulation. The simulation model cannot annotate size and process information due to poor interface between DEFORM software and CAD software. Thus,a 3D annotation module is developed with secondary development technology of UG NX software. Consequently,the final process model with dimension and process information is obtained. Then,with the current 3D process management system,the 3D punching and forming process design of cartridge cases can be completed further. An example is also provided to illustrate that the relative error between the simulation process model and the physical model is less than 2%,which proves the validity and reliability of the proposed method in this study.

Three-Dimensional Cerebral Aneurysm Models for Surgical Simulation and Education—Development of Aneurysm Models with Perforating Arteries and for Application of Fenestrated Clips

We modified a three-dimensional cerebral aneurysm model for surgical simulation and educational demonstration. Novel models are made showing perforating arteries arising around the aneurysm. Information about perforating arteries is difficult to obtain from individual radiological data sets. Perforators are therefore reproduced based on previous anatomical knowledge instead of personal data. Due to their fragility, perforating arteries are attached to the model using hard materials. At the same time, hollow models are useful for practicing clip application. We made a model for practicing the application of fenestrated clips for paraclinoid internal carotid aneurysms. Situating aneurysm models in the fissure of a brain model simulates the real surgical field and is helpful for educational demonstrations.

基于Solidworks Simulation的三坐标测量仪动态误差分析

采用三坐标测量仪进行高速测量时,由于受附加惯性力及自身重力的影响,机体会变形,从而导致动态误差。对三坐标测量机的动态误差进行理论分析;利用Solidworks Simulation有限元分析方法对移动桥进行受力变形分析;在z轴静止状态下,推导出滑架沿y轴方向加速(减速)和匀速的运动状态下动态误差补偿模型。仿真结果表明:各运动状态下的动态误差有效降低,为提高三坐标测量机的测量精度奠定基础。

基于SolidWorks的鲜枣采摘末端执行器设计与运动仿真

[目的]满足鲜枣采摘机器人采摘需求,提升采摘成功率,降低采摘过程中对相邻果实的影响。[方法]基于SolidWorks设计了一种鲜枣采摘专用末端执行器。首先根据鲜枣特性对末端执行器进行结构设计,计算各零件尺寸和参数;其次采用SolidWorks软件绘制各零件3D模型,并在软件中进行装配;最后对该末端执行器进行了运动仿真分析。[结果]该末端执行器各零件配合良好、无干涉现象,材料满足强度要求,能够实现正常抓取,运行平稳、可靠,结构能够满足鲜枣采摘的基本要求。[结论]本研究可为鲜枣采摘机器人的后续研究提供理论支持与借鉴。

3D Modeling and Simulation of Fancy Fabrics in Weft Knitting

Weft knitted fancy fabrics are widely used in knitted garment design. Due to the complexity of the structures, their modeling and simulation needs to be solved in three-dimensional (3D) CAD developments. In this paper, 3D loop geometrical models of weft knitted fancy structures, including tuck stitch, jacquard stitch, transfer stitch and fleecy stitch, were developed based on an improved model of plain loop, and their central axes as some 3D space curves were achieved by using Non-Uniform Rational B-Splines (NURBS). The 3D visual simulation programme was written in C++ programming language using OpenGL, which was a function library of 3D graphics. Some examples of weft knitted fancy fabrics were generated and practical application of 3D simulation was discussed.

基于SolidWorks Simulation的压力容器受压元件建模及应力分析设计

针对形状特殊的压力容器受压元件设计,当无法按照压力容器设计第一强度理论的标准计算式进行设计时,若按照验证性爆破试验设计方法,设计周期长、试错成本高。给出了另外一种设计方法,即采用SolidWorks Simulation软件,将压力容器受压元件进行三维建模、应力分析和结果评定,并给出了优化设计的结果,最后结论表明该方法可以满足工程应用要求。

Application of Three-Dimensional Visual Simulation in Tidal Defense Engineering

Any tidal defense engineering involves the collection and analysis of massive information about engineering structures and their surrounding environment. Traditional method, which is carried out mainly by means of twodimensional drawings and textures, is not efficient and intuitive enough to analyze the whole project and reflect its spatial relationship. Three-dimensional visual simulation provides an advanced technical means of solving this problem. In this paper, triangular irregular network (TIN) model simplified by non-uniform rational B-splines (NURBS) technique was used to establish the digital terrain model (DTM) of a super large region. Simulation of dynamic water surface was realized by combining noise function with sine wave superposition method. Models of different objects were established with different modeling techniques according to their characteristics. Application of texture mapping technology remarkably improved the authenticity of the models. Taking the tidal defense engineering in the new coastal region of Tianjin as a case study, three-dimensional visual simulation and dynamic roaming of the study area were realized, providing visual analysis and visible demonstration method for the management and emergency decision-making associated with construction.

The numerical simulation for a 3D two-phase anisotropic medium based on BISQ model

Biot-flow and squirt-flow are the two most important fluid flow mechanisms in porous media containing fluids. Based on the BISQ （Biot-Squirt） model where the two mechanisms are treated simultaneously, the elastic wave-field simulation in the porous medium is limited to two-dimensions and two-components （2D2C） or two-dimensions and three-components （2D3C）. There is no previous report on wave simulation in three- dimensions and three-components. Only through three dimensional numerical simulations can we have an overall understanding of wave field coupling relations and the spatial distribution characteristics between the solid and fluid phases in the dual-phase anisotropic medium. In this paper, based on the BISQ equation, we present elastic wave propagation in a three dimensional dual-phase anisotropic medium simulated by the staggered-grid high-order finite-difference method. We analyze the resulting wave fields and show that the results are an improvement.

基于Solidworks Simulation的液压葫芦吊钩设计及分析

利用SolidWorks搭建16T液压葫芦模型,设计了其吊钩组件并确定了承载圆环链链条数目及钩子位置,通过simulation分析了吊钩组件的受力模型,降低了其重量,从而为吊钩组件的试制和优化设计提供可靠的依据。

A Three-Dimensional Water Quality Model and Its Application to Jiaozhou Bay, China

A three-dimensional coupled physical and water quality model was developed and applied to the Jiaozhou Bay to study water quality involving nutrients, biochemical oxygen demand, dissolved oxygen, and phytoplankton that are closely related to eutrophication process. The physical model is a modified ECOM-si version with inclusion of flooding/draining processes over the intertidal zone. The water quality model is based on WASP5 which quantifies processes governing internal nutrients cycling, dissolved oxygen balance and phytoplankton growth. The model was used to simulate the spatial distribution and the temporal variation of water quality in the Jiaozhou Bay for the period of May 2005 to May 2006. In addition, the effect of reduction of riverine nutrients load was simulated and evaluated. The simulated results show that under the influence of nutrients discharged from river, the concentrations of nutrients and phytoplankton were higher in the northwest and northeast of the bay, and decreased from the inner bay to the outer. Affected by strong tidal mixing, the concentrations of all state variables were vertically homogeneous except in the deeper regions where a small gradient was found. Obvious seasonal variation of phytoplankton biomass was found, which exhibited two peaks in March and July, respectively. The variation of riverine waste loads had remarkable impact on nutrients concentration in coastal areas, but slightly altered the distribution in the center of the bay.

Three-dimensional tidal current numerical model of the Oujiang Estuary

The characteristics of three-dimensional （3-D） tidal current in the Oujiang Estuary are investigated according to in situ observations. The Oujiang Estuary has features of irregular coastline, complex topography, many islands, moveable boundary, and submerged dyke, therefore, σ 3-D numerical model oil an unstructured triangular grid has been degeloped. The σ coordinate transforination, the moveable boundary and submerged dyke treatment techniques were employed in the model so it is suitable for the tidal simulations in the Oujing Estuary with submerged dyke and moveable boundary problems. The model is evaluated with the in situ data, and the results show that the calculated water elevations at 19 stations and currents at 19 profiler stations are in good agreement with measured data both in magnitude and phase. This numerical model is applied to the 3-D tidal circulation simulations of experiments in stopping flow transport through the South Branch of the Oujiang Estuary, and the feasibility to cutoff the flow in the South Branch of the Oujiang Estuary is demonstrated by numerical simulation experiments. The developed numerical model simulated the 3-D tidal current circulations in complicated coastal and estuarine waters very well.

NUMERICAL SIMULATION OF SOUTH CHINA SEA MONSOON ONSET BASED ON GRAPES MODEL AND EXPERIMENTS ON INITIAL MODEL FIELDS

The Global and Regional Assimilation and Prediction System (GRAPES), a limited-area regional model, was used to simulate the onset of South China Sea summer monsoon. In view of the relatively insufficient information about the initial field in simulation predictions, the Advanced Microwave Sounding Unit-B (AMSU-B) data from a NOAA satellite were introduced to improve the initial values. By directly using the 3-dimensional variational data assimilation system of GRAPES, two schemes for assimilation tests were designed. In the design, Test 1 (T1) assimilates both sounding and AMSU-B data, and Test 2 (T2) assimilates only the conventional sounding data, before applying the model in simulation forecasts. Comparative experiments showed that the model was very sensitive to initial fields and successful in reproducing the monsoon onset, allocation of high- and low-level wind fields during the pentad of onset, and the northward advancement of the monsoon and monsoon rain bands. The scheme, however, simulated rainfall and the location of the subtropical high with deviations from observations. The simulated location of the subtropical high was more westward and northward and the simulated rainfall for the South China Sea was larger and covered a broader area.

The 3D simulation and optimized management model of groundwater systems based on eco-environmental water demand

Through the study of mutual process between groundwater systems and eco-environmental water demand, the eco-environmental water demand is brought into groundwater systems model as the important water consumption item and unification of groundwater抯 economic, environmental and ecological functions were taken into account. Based on eco-environmental water demand at Da抋n in Jilin province, a three-dimensional simulation and optimized management model of groundwater systems was established. All water balance components of groundwater systems in 1998 and 1999 were simulated with this model and the best optimal exploitation scheme of groundwater systems in 2000 was determined, so that groundwater resource was efficiently utilized and good economic, ecologic and social benefits were obtained.

基于SolidWorks的平面连杆机构实体运动分析

研究了在三维机械设计系统 Solid Works平台上进行平面连杆机构运动仿真的方法。基于 Solid Works平台 ,以 API为应用程序接口 ,以型转化及广义型转化法为运动分析的理论基础 ,通过机构的配合特征和装配体中各零件几何信息的提取与转换 ,利用面向对象的VC+

精密排种器的特征造型及其装配关联设计——基于Solidworks

为了提高排种器的改型设计和系列化设计的效率,基于Solidworks采用自上而下的设计方法对推种式型孔轮排种器进行三维特征造型和装配关联设计;同时,探讨了关键零件的三维特征造型过程中的技术要点和基于装配的关联设计的技术关键,动态模拟装配过程、关联产生二维工程图。

基于SolidWorks的行星齿轮传动机构三维建模

以某型直升机主减速器为实物参考,利用SolidWorks软件实现了渐开线齿轮的精确三维建模,并建立了该减速器单级行星传动机构在SolidWorks软件中的装配体模型。应用COSMOSMotion插件高效、直观的计算仿真功能实现了行星齿轮机构的运动仿真。

双行木薯收获机虚拟设计与运动仿真——基于SolidWorks

针对我国木薯收获机设计中存在的设计手段落后和设计效率低下等问题,采用基于特征的参数化造型软件SolidWorks对木薯收获机进行参数化造型,设计了新型的悬挂式双行木薯收获机。同时,对木薯收获机简化模型进行了运动仿真,确保机具在理论上满足使用要求,为木薯收获机的研制提供了一种新方法,也为同类机具的研制提供了参考。

基于SolidWorks与ADAMS的工业机器人动力学仿真

目的工业码垛机器人因其负载大、自动化程度高等优点,被广泛应用于食品、药品、化肥等生产线中,但是机器人动力学模型的建立较为困难,为了得到码垛机器人设计参数,运用SolidWorks与Matlab联合仿真。方法通过SolidWorks建立码垛机器人实体模型,并将其导入到ADAMS中,在仿真软件中通过设置具体参数,得到机器人动力学仿真模型。结果通过SolidWorks与ADAMS的结合仿真,可以大大缩短设计周期,有效地获得码垛机器人的动力学特性参数。结论运用SolidWorks与Matlab联合仿真,可以形象直观地模拟机器人的三维运动情况,并获取其动力学特性参数。