自动化生成仿真粒子的方法

现代工程仿真软件不仅具有分析连续介质的功能，如有限元方法计算结构、流体、或电磁场。也有增强了对非连续粒子系统的计算能力，如纯粒子的分子动力学计算，离散元，光滑粒子流体动力学（SPH），以及与有限元耦合的计算。计算粒子系统的首要条件就是能够在模型中产生粒子，包含了粒子的位置，形状，和体积大小等数据。这与有限元分析需要生成含有节点和单元信息的网格类似。 Image 在计算粒子体系时，第一步是生成粒子的位置，大小，和形状。因此，粒子生成器也就成为整个分析系统的关键部分。好的粒子生成器可以快速生成初始状态粒子，还可以根据不同的形状和边界来生成粒子。常见的自动化粒子生成方式有，晶体点阵，网络生长，和有限元网格转换。本文就讨论常见的可用于SPH系统的粒子生成方法，及其实现机理。 晶体点阵（Lattice） 使用点阵方式生成粒子是一种常见的方式，尤其适用于材料的微小尺度的计算。如材料晶体结构中常见的FCC、BCC等结构。当初始的点阵结构给定以后，粒子生成器会复制这个结构并铺满整个区域。 Image 对于此类型的粒子生成，需要用户提供整个模拟区域的边界，通常是一个矩形盒子，每个点阵中粒子类型，和粒子之间的位置。算法上，这也是一种简单直接的粒子生成方式，大量应用于分子动力学等粒子生成之中。 有限元网格转换 有限元网格是一种包含了节点与单元的数据，根据模型的不同，单元的类型也会不同。这种网格是有限元分析计算中的基础数据之一。代表性的有四面体和六面体实体单元网格，和三角形与四边形平面网格。网格可以表达不规则的形状，因此，转换成为粒子后，也可以表征不规则的形状。在与有限元结合的粒子系统中，这种粒子生成方式，能够方便与有限元计算进行耦合，如常见的粒子有限元和SPH分析。 Image 转换网格到粒子的常用方法是，获取网格每个单元的重心，和单元的直径大小。以此确定每个粒子的位置和大小。原则上每个单元会对应生成一个粒子。由于有限元网格的密度可能不均匀，以此方法生成的粒子分布也不均匀。有时需要再将生成的粒子进行均匀化处理。对于位于边界的粒子，可能还需要标记额外的内容，以方便在后续的分析中施加边界条件。如流体动力学计算(CFD)中，会在某个流入边界中不断生成粒子进入仿真区域。WELSIM已经能够根据有限元网格生成粒子的功能。 基于网络增长生成 另一种常见的粒子生成方式是通过网络增长，具体的算法上常使用树与分支的方式。初始一个树状结构的主干，允许分支在固定区域内按照一定方式生长，生成新的节点，即粒子。在输入起始点和第二个点，片段长度，梯度，初始形状等参数后。这种生成方式的核心是如何创立新的分支，通常的做法是，如果新节点与当前某个节点位置很近，或者都属于同一个父节点，则不会生成这个新节点（分支）。基于网格生成粒子的方法使用了随机数，因此生成的粒子会有一定的随机性。 Image 总结 本文介绍了仿真软件中，自动化生成粒子的常用方法。对于有限元相关的软件，网格转化为粒子的方式更为实用，可以直接将生成的粒子应用于有限元耦合计算中。通用有限元软件WELSIM已经支持了从网格到粒子的转化，用户还可以将生成的粒子导出，用于其他类型的分析。

Orthotropic Hill Plasticity Model

In the field of structural mechanics, the plastic deformation processes of many materials are anisotropic in nature. Examples include composite materials, titanium alloys, additively manufactured structures, and multiscale materials. In these cases, traditional isotropic yield criteria are no longer sufficient to accurately describe the behavior, and appropriate models are required to characterize anisotropic plastic yielding. Commonly used anisotropic yield functions include the Hill, Barlat, Banabic, and Cazacu models. Among them, the Hill model was proposed relatively early and has a wide range of applications. It performs particularly well in describing orthotropic materials and is extensively used in structural finite element analysis. hill_augmented_manufacturing The Hill model is named after Professor R. Hill, who was appointed Professor of Applied Mathematics at the University of Nottingham in 1953. His 1950 work “The Mathematical Theory of Plasticity” laid the foundation for modern plasticity theory. He is widely regarded as one of the most significant contributors to solid mechanics in the second half of the 20th century. It’s important to note that the Hill model is not the only yield criterion for orthotropic anisotropic materials. Alternatives include Barlat models with 3 or 6 parameters, or modified versions of the Hill yield criterion. This article focuses only on the classical Hill model, but similar approaches can be used to determine parameters for other yield models. The Hill model is applicable for analyzing plastic deformation in anisotropic materials and can be viewed as a generalized form of the von Mises yield criterion tailored for anisotropic behavior. It is particularly useful for orthotropic plastic materials in structural engineering applications. The Hill yield criterion is given by: hill_yield_equation For shell elements, the yield function is given by: hill_yield_equation2 Where σ represents the stress components. For 3D models, F to H are six anisotropy calibration coefficients, also known as Hill parameters, which can be determined through material experiments. For shell elements, only four parameters F to N are required. In computational mechanics, solid elements typically use yield stress ratios (or yield stresses) R11, R22, R33, R12, R13, R23 to calculate Hill parameters. To determine the yield stress ratios, the material’s yield stresses under different loading conditions must be measured: σ11, σ22, σ33 are obtained from tensile tests. σ12, σ13, σ23 are obtained from shear tests. For shell elements, Lankford parameters are used to determine the Hill parameters. A Lankford parameter rₐ is defined as the ratio of plastic strain in the plane to that in the thickness direction. For orthotropic anisotropy, rₐ can be obtained from simple tensile tests: r₀₀: tensile direction aligned with the orthotropic axis 1. r₉₀: tensile direction perpendicular to the orthotropic axis 1. Once r₀₀, r₄₅, r₉₀ are measured, the Hill parameters can be calculated. Higher Lankford values indicate better formability. Most finite element analysis software requires the user to input either R values or Lankford parameters for the Hill model. Once these are specified, the Hill yield criterion equation can be fully determined. Support for the orthotropic Hill model in WelSim The complexity of the Hill model lies in parameter input and solving the orthotropic nonlinear behavior. The general-purpose simulation software WESLIM supports transient analysis involving the Hill model. The free material editing software MatEditor supports Hill material model input. Currently, MatEditor supports three types of orthotropic Hill plastic material models and can generate OpenRadioss material input scripts: Law32, Law73/74, and Law93. mateditor_hill_orthotropic Conclusion The Hill model effectively describes orthotropic yield behavior, especially in tension-compression directions and in scenarios with minimal shear deformation. It can also be used to model the mechanical behavior of metallic lattice structures in additive manufacturing. Hill parameters can be determined via R or Lankford parameters. When these parameters are unavailable from experiments, they can be approximated using curve fitting methods. WelSim already provides support for the Hill model and can be integrated with OpenRadioss for transient simulations involving orthotorpic plastic deformation. WelSim and authors have no direct affiliation with developers of OpenRadioss. References to OpenRadioss here are solely for technical blogging and software usage discussion.

正交各项异性Hill 塑性模型

在结构力学领域，很多材料的塑性变形过程是各项异性的，如复合材料，钛合金，增材制造结构，多尺度材料等。这时传统的各项同性屈服准则就无法准确描述此过程，需要有合适的模型来描述各项异性塑性屈服，常用的各项异性屈服函数有：Hill 系列、Barlat 系列、Banabic和 Cazacu等。其中，Hill模型是提出较早，且应用范围广。尤其是在描述正交各向异性材料，Hill模型有着很好的表现，被广泛应用于结构有限元计算中。 Image Hill塑性模型是以R. Hill教授命名的，他在1953年被任命为诺丁汉大学应用数学教授。于1950年发表的《塑性数学理论》奠定了塑性理论的基础。被广泛认为是20世纪下半叶固体力学基础最重要的贡献者之一。 Hill模型并不是描述正交各项异性屈服的唯一准则，例如3参数或者6参数的Barlat本构模型，或者修改版的Hill屈服准则。本文仅对经典的Hill模型进行讨论，其他屈服模型也可以采用类似的方法进行确定。 Hill适用于各项异性的塑性变形分析。可以看作是用于各项异性屈服行为的von Mises屈服准则的通用形式。在实际的结构工程中，常用于正交各项异性的塑性材料。 Hill 的屈服准则如下： Image 对于壳单元，屈服函数如下 Image sigma是应力分量，对于三维模型，F-H为六个各向异性校准系数，又称作Hill参数，可以通过材料实验得到。对于壳单元，只需要F-N 4个参数。 在计算上，固体单元使用 屈服应力率 （或屈服应力）R11, R22, R33, R12, R13, R23来计算Hill参数。为了得到屈服应力率，材料在两种载荷工况下的屈服应力需要被测量。其中，屈服应力sigma11, sigma22, sigma33从拉伸测试中获得。屈服剪应力 sigma12, sigma13, sigma23从剪切测试中获得。 对于壳单元，会使用Lankford参数组来决定Hill参数。Lankford参数r_a是 平面上与厚度方向上塑性应变的比值。对于正交各项异性，r_a可以从简单的拉伸测试中获得。比如r00 从拉伸测试中，载荷方向与正交第一方向一致。r90的载荷方向与正交第一方向垂直。一旦Landford参数r00, r45, r90获得，便可以计算得到Hill参数。Landford数值越大，表示材料有更好的延展性。 在大多数有限元分析软件中，Hill模型要求用户输入R或者Landford参数。通过确定R或者Landford参数，即可确定Hill屈服准则方程。 WelSim对正交各项异性Hill模型的支持 Hill模型的复杂性在于模型参数的输入，和正交各项异性的非线性的求解。通用仿真软件WELSIM支持含有Hill的瞬态动力学计算，免费的材料编辑软件MatEditor支持Hill材料模型的输入。目前MatEditor已经支持了三种正交各项异性Hill塑性材料模型，并支持生成OpenRadioss的材料卡片Law32， Law73/74和Law93。 Image 总结 Hill模型可以描述材料的正交各项异性屈服行为。尤其是在拉压方向，以及剪切变形较小的场合，Hill模型也可以描述金属增材点阵结构的力学行为。 Hill参数可以通过R或者Landford参数确定，当这些参数无法从实验中获得时，也可以通过曲线拟合的方法近似得到。 WelSim已经对Hill模型有了一定支持，能够联合OpenRadioss进行含有各向异性塑性变形的瞬态动力学计算。 WelSim与作者和OpenRadioss开发者没有直接关系。这里引用OpenRadioss仅用作技术博客文章与软件使用的参考。

Running OpenGL-based applications in a sandbox/virtual machine

Windows Sandbox is a built-in virtual machine in the Windows operating system that allows users to test and run uncertain applications. The sandbox is seperate from the host OS, so applications can run safely in isolation. It is temporary; once closed, all software, files, and states within the sandbox are deleted. Each time the sandbox is launched, a brand-new instance is created. Unlike other virtual machines like VirtualBox, launching Windows Sandbox doesn’t require installing or purchasing a separate OS, which is a significant advantage. However, the sandbox is only available on Windows Professional or Enterprise editions. When running OpenGL-based software in the sandbox, display issues may arise. This is because Windows Sandbox does not natively support OpenGL. If an application depends on OpenGL but does not include the necessary OpenGL libraries, issues can occur such as a missing main interface. For example, MatEditor, a free engineering simulation material editor from the WelSim suite, may not display its main window the first time it is opened in the sandbox. This is because the required OpenGL libraries in the sandboxed OS are absent. The fix is straightforward — simply add the OpenGL libraries to MatEditor. Download the Mesa OpenGL library from GitHub. The project name is mesa-dist-win. 2. Choose the appropriate version for your operating system and build type. In this case, the release-msvc version is selected. 3. Extract the files, open the extracted directory, and type cmd in the address bar to open a command prompt. Then, run the perappdeploy.bat file. 4. The command line will launch and display relevant information. Press any key to continue. 5. Follow the prompts by inputting the executable file folder: C:\Program Files\WELSIM\MatEditor, the executable file name: runMatEditor.exe, and selecting the processor architecture: x64. 6. The OpenGL library is now added to MatEditor. You can re-run the application, and the main window should now display correctly. Conclusion This article uses MatEditor as an example to demonstrate how to resolve OpenGL library dependency issues in Windows Sandbox. The same method applies to other environments lacking OpenGL support, such as Windows systems running in VirtualBox. Besides MatEditor, other WelSim products such as the general simulation software WELSIM and the free curve fitting tool CurveFitter are also based on OpenGL and will require similar configuration when used in the sandbox. WelSim and its developers are not directly affiliated with OpenGL, Windows, Linux, VirtualBox, or Sandbox. References to these technologies are solely for technical blog purposes and software usage guidance.

沙盒/虚拟机中运行基于OpenGL的应用软件

Windows沙盒（Sandbox）是Windows操作系统中自带的虚拟机。对于不确定的应用程序，可以先在沙盒里测试运行。沙盒与当前的操作系统隔离，可以安全地在隔离状态下运行应用程序。沙盒是临时的，关闭后，系统将删除所有软件和文件以及状态。 每次打开应用程序时，都会获得沙盒的全新实例。打开沙盒系统无需安装或购买一份新的操作系统，这是相对于VirtualBox等虚拟机来说一个优势，但是只有在Windows专业版或企业版才有沙盒功能。 在沙盒环境下运行含有OpenGL的软件时，可能会遇到一些显示问题。由于沙盒环境下没有对OpenGL的原生支持，因此，当应用软件基于OpenGL但不包含OpenGL依赖库的时候，会出现显示的问题，如没有主界面等现象。WelSim系列的MatEditor是一款免费的工程仿真材料编辑软件，当在沙河中首次打开时，可能会无法显示主窗口，是由于沙盒的操作系统中没有OpenGL的相关库文件。 Image 解决方法很容易，只需要为当前的MatEditor程序添加OpenGL的库即可。 1. 从GitHub上下载Mesa的OpenGL库，项目名称为mesa-dist-win。 Image 2. 选择对应的操作系统和编译方式版本。这里选择的是release-msvc版本。 Image 3. 解压后，在解压目录中输入cmd，进入命令行模式。并运行perappdeploy.bat文件。 Image 4. 会进入命令行模式，并显示相关信息。按下任意键后。 Image 5. 根据提示，分别输入可执行文件的文件夹C:\Program Files\WELSIM\MatEditor。可执行文件的名称runMatEditor.exe。选择处理器构架为x64。 Image 6. 为MatEditor添加OpenGL库文件的工作已经完成。可以再次运行MatEditor应用。主窗口与界面完美显示。 Image 总结 本文通过以MatEditor软件为例，介绍了在Windows沙盒中解决和OpenGL依赖库有关的问题。此方法同样适用没有OpenGL支持的操作系统环境，如Virtual Box中的Windows系统。除了MatEditor，WelSim系列下的通用仿真软件WELSIM，和免费的曲线拟合软件CurveFitter也都基于OpenGL，因此在沙盒环境下，也需要做类似配置。 WelSim与作者和OpenGL, Windows, Linux, VirtualBox, SandBox等开发机构没有直接关系。这里引用OpenGL, Windows, Linux, VirtualBox, SandBox仅用作技术博客文章与软件使用的参考。

Finite Element Analysis of Plastic Roll Forming

Roll forming, also known as cold roll forming, is an industry-wide process used to manufacture and form metal. Through successive deformation, it shapes the metal workpiece into specific profiles using a series of forming rollers arranged in sequence. This forming method offers high production efficiency, reduced waste, and enhanced product strength. Roll forming is widely applied in industrial sectors such as automotive manufacturing. Simulation of roll forming is a common type of finite element analysis (FEA). With this analysis, one can predict the degree of deformation of the workpiece, the stresses and strains it undergoes, as well as determine the roller dimensions and operating speeds required for success. Since this type of analysis involves nearly all aspects of structural calculations, such as multi-load steps, nonlinear plasticity, various types of contact algorithms, rigid body dynamics, and both solid and shell elements, it is considered one of the most copmlex and difficult-to-converge models in structural analysis. An analysis of roll forming not only places high pressure on the solver, but also on the skill of its pre- and post-processors. The general-purpose engineering simulation software WelSim, when combined with the powerful open-source FEA solver OpenRadioss, can effectively simulate various plastic forming and forging processes. This article demonstrates how to perform a roll forming simulation from a practical perspective. Analysis Steps 1. Open WelSim and set units. In this case, we use the kg-mm-s system. 2. Create a new aluminum alloy material named myPlastic, with the following properties: Density: 2.7e-6 kg/mm³ Young’s Modulus: 70 GPa Poisson’s Ratio: 0.33 Johnson-Cook Plasticity Properties: Initial Yield Stress: 300 MPa Hardening Constant: 360 MPa Hardening Exponent: 0.08 After editing the material parameters, close the material window to proceed with the analysis. 3. Create a new FEM project and set the analysis type to Explicit Transient Structural Analysis in the Properties window. 4. Import the geometry model as shown below: In this assembly, the bottom two rotating rollers transport the workpiece, while the top roller presses down on the workpiece. The workpiece is a square tube with chamfered corners. The cross-section of the tube is shown below: For the three cylindrical rollers, set them as Shell structures. The Material is Structural Steel; Thickness is 1 mm. Set the Integration Points property to 3, and set the Rigid Body property to true. For the deformable square tube workpiece, define it as a Solid structure, and assign the aluminum alloy created in Step 2 to the Material. 5. In the Mesh Settings window, set the Maximum Element Size to 10 mm. WelSim automatically meshes based on geometry type. The square tube is meshed with solid elements. The thin-walled rollers are meshed with shell elements. 6. In the Contact property windows, this model defines three contact pairs: two frictionless, and one frictional. 6.1 The first contact pair is frictional; it is between the bottom front roller and square tube. The friction coefficient is 0.9 to provide driving force as the roller rotates. 6.2 The second contact pair is frictionless and is between the rear bottom roller and tube. 6.3 The third contact pair is frictionless and is between the top pressing roller and tube. 7. Now, define this analysis to be multi-step. In the properties of Study Settings object, set up 3 load steps. The end times for each step are: 0.04s, 0.045s, and 0.1s. Set the solver to OpenRadioss, or leave it as the default (Program Controlled). When performing explicit structural dynamics, WelSim defaults to OpenRadioss as the solver. 8. Next, define four boundary conditions for this analysis. 8.1. The Displacement boundary is set for the top roller. The roller moves downward 20 mm at a constant speed during first load step, then holds position. 8.2. A Constraint condition is set for top roller to prevent some rotation during simulation, only Z direction translation and X axis rotation are allowed. 8.3. Now, define the constraints for the bottom rollers to only allow rotation around the X-axis by setting X to False. 8.4. The last boundary condition is the angular velocity of the front bottom roller, which is set to a speed of 200 rad/s, and it starts in the second load step. 9. Now it’s time to solve the Model. You can simply click the Solve button to begin the computation. If it’s your first time using WelSim with OpenRadioss locally, you’ll need to download the OpenRadioss solver and configure its path in WelSim’s Preferences. 10. After computation, you can view results by clicking the Answer object. The Table and Chart display energy and kinetic quantities over time. These quantities include: Contact energy, External work, Internal energy, Kinetic energy, Mass, Momentum, etc. 11. You also can add result objects like stress, strain, displacement to evaluate the specific results of the domain. To see the deformation, you need to enable the Show Deformation property in the 3D View tab. The figure below displays the von-Mises stress contour; the Table and Chart display how stress evolves over time. WelSim also supports the generation of animation, just click the record button in the Chart window to create an animation of the 3D view. The example animation is shown here: https://www.youtube.com/watch?v=-38eodbujns Conclusion This article demonstrates how to build and analyze a plastic roll forming simulation using a real-world example. OpenRadioss proves to be a powerful tool for transient structural analysis. Paired with WelSim's convenient pre- and post-processing capabilities, OpenRadioss becomes easier to use and integrate. WelSim acts as both the pre- and post-processors in this case, efficiently generating complex input scripts and directly reading the result files for display. WelSim seamlessly integrates with the OpenRadioss solver. The geometry and test files used in this article are open-sourced and available in WelSim's official test case repository: 🔗 https://github.com/WelSimLLC/WelSimAutoTests WelSim has no direct affiliation with the developers of OpenRadioss. References to OpenRadioss are for technical blog and software usage purposes only.

塑性辊压成型的有限元仿真

塑性辊压成型又称冷弯成型，是工业中常用的金属制造与成型方式。是通过顺序配置的多道次成形轧辊，把金属工件不断进行变形，以制成特定形状。这种成型方式生产效率高，节约材料，增加产品强度，广泛应用于如汽车生产等工业部门。 Image 辊压成型的仿真也是常见的有限元分析类型。通过这种分析，可以预测工件的变形程度，承受的应力应变情况，以及所需要辊子的尺寸和运转速度。由于此类分析几乎涉及了结构计算的所有因素，如多载荷步，塑性非线性变形，各种类型的接触算法，刚体动力学，和各种实体与板壳单元。可以说是结构分析中最复杂，最难以收敛的模型之一。这不仅对求解器提出很高的要求，也对前后处理器也需要比较完善的功能。 通用工程仿真软件 WelSim，在结合强大的开源瞬态求解器OpenRadioss后，可以很好的模拟各种塑性成型等锻造过程。本文就从实际操作角度，演示如何进行滚动压铸成型的仿真分析。 分析步骤 1. 打开WelSim主界面，并设置单位。这里，我们设置kg-mm-s。 Image 2. 建立一个新的铝合金材料，并命名为myPlastic，设置的属性分别如下。 密度：2.7e-6 kg/mm3。杨氏模量：70 GPa。泊松比：0.33。 Johnson-Hook塑性属性，初始屈服应力：300 MPa。硬化常数: 360 MPa。硬化指数: 0.08。 Image 编辑完成材料参数后，关闭材料窗口。进行后续分析操作。 3.新建一个FEM项目工程，并在属性窗口中，设置为显式瞬态结构分析。 Image 4. 导入几何模型，如下图所示。 Image 底部有两个可转动辊轴，用于传送工件。上转辊用于下压工件。工件为方管结构，四角有倒角。方管的横截面如下图所示。 Image 对于3个圆柱形辊子，在属性窗口中设置为壳体结构，材料为结构钢，厚度保持1mm不变，积分点保持3个不变，同时将刚体选项设置为真。如下图所示， Image 对于受挤压成型的方管工件，定义为实体结构，并赋予在第2步创建的铝合金塑性材料。 Image 5. 网格划分。将最大单元尺寸设置为10mm。WelSim会自动根据几何类型进行划分单元。方管会使用实体单元网格划分。薄壁滚轴是使用壳单元划分。 Image 6. 添加接触。本算例中，需要添加3对接触对，其中两个无摩擦接触对，一个有摩擦接触对。第一个接触对是底部第一滚轴与方管的接触，设置为有摩擦，同时摩擦系数为0.9。之所以设置成有摩擦，是为了在滚轴转动时，摩擦力能将方管向一个方向传递。 Image 第二个接触对是底部第二滚轴与方管的接触，定义为无摩擦接触。如下图所示， Image 第三个接触对是顶部的压辊与方管的接触，同样定义为无摩擦接触。 Image 7. 在Study Settings节点中设置多载荷步分析。由于分析工况的需要，我们将载荷步设置为3步，每一个载荷步的结束时间分别是0.04s, 0.045s, 0.1s。将求解器设置OpenRadioss或者保持默认的自动选择求解器。WelSim在进行显式结构动力学计算时，会默认使用OpenRadioss求解器。 Image 8. 设置边界条件。这里要设置四个边界条件，用于完成整个分析中所需的约束与载荷。 8.1 对顶部的辊子设置位移边界条件。上辊在第一个时间步内匀速下压20mm, 并在之后的过程中保持在这个位置。 Image 8.2 对上辊设置约束边界条件。目的是防止上辊在接下来的计算中产生转动。因此，只允许Z方向和X轴方向运动。 Image 8.3 对底部两个辊子都施加约束边界条件。只允许以X轴方向的转动。 Image 8.4 对底部前端的辊子施加以X为轴的旋转角速度，用于传动方管。角速度的大小为200 rad/s，从第二个载荷步开始旋转辊子。 Image 9. 设置完成后，即可以点击求解按钮，进行计算。如果是在本地第一次使用WelSim和OpenRadioss的联合求解，还需要下载OpenRadioss求解器至本地，同时在WelSim的首选项中进行简单配置，输入OpenRadioss的目录地址。即可联立求解。 Image 10. 计算完成后，点击答案节点，会在表格与曲线窗口，显示整个时间历程下，各种能量和动能的分布。这些量包括，接触能量，外部做功，内能，动能，质量，和动量等。如下图所示。 Image 11. 还可以添加如应力、应变、位移等结果节点，评价后即可得到三维云图显示。当需要打开变型显示时，可以在三维显示属性窗口中，将显示变形属性设置为真。即可看到方管变形和位移后的状态。同时，表格和曲线窗口显示整个应变随时间变化的状况。 Image WelSim还支持快速生成动画，用户可以点击曲线窗口上的录像按钮，即可生成3D视图窗口中的动画文件。本算例的应力结果动画如下所示。 总结 本文通过一个实例，演示了如何建立塑性辊压模型，并得到计算结果。OpenRadioss被证明是一款功能强大的瞬态结构动力分析软件，通过WelSim便捷的前后处理能力，使得OpenRadioss的更加易于使用。WelSim在本例中，作为前后处理工具，快速生成包含复杂内容的求解文件，同时可以直接读取结果文件并显示，体现了和OpenRadioss求解器无缝整合的功能。 本文所用的几何文件和测试文件已经开源，并共享在 WelSim的官方测试库中，https://github.com/WelSimLLC/WelSimAutoTests。 WelSim与作者和OpenRadioss开发机构没有直接关系。这里引用OpenRadioss仅用作技术博客文章与软件使用的参考。