弹性力学仿真软件：ADINA：非线性静力分析进阶

弹性力学仿真软件：ADINA：非线性静力分析进阶1软件介绍与安装1.1ADINA软件概述ADINA(AutomaticDynamicIncrementalNonlinearAnalysis)是一款由美国ADINAR&DInc.开发的高级有限元分析软件，广泛应用于结构、流体、热力学和多物理场耦合分析。其非线性静力分析功能特别强大，能够处理复杂的材料非线性、几何非线性以及接触问题，是工程设计和研究中不可或缺的工具。1.2ADINA安装与配置1.2.1系统要求操作系统:Windows10/11,Linux处理器:多核处理器内存:至少16GBRAM硬盘空间:至少10GB可用空间1.2.2安装步骤下载软件:从ADINA官方网站下载最新版本的安装包。解压:使用解压软件打开下载的安装包。运行安装程序:找到并运行安装程序，通常为ADINA_Installer.exe。许可设置:输入ADINA许可信息，通常包括许可服务器的IP地址和端口号。选择组件:选择需要安装的组件，如ADINA结构分析、流体分析等。安装路径:选择软件的安装路径。完成安装:按照安装向导完成安装过程。1.2.3配置许可许可服务器:确保许可服务器已正确配置并运行。环境变量:在系统中设置ADINA的环境变量，指向许可文件或服务器。测试连接:使用ADINA提供的许可测试工具检查与许可服务器的连接。1.3用户界面与基本操作1.3.1用户界面ADINA的用户界面直观且功能丰富，主要分为以下几个部分：-菜单栏:提供软件的主要功能选项。-工具栏:快速访问常用工具。-模型树:显示当前模型的结构和组件。-图形窗口:显示和操作模型的3D视图。-状态栏:显示当前操作状态和提示信息。1.3.2基本操作1.3.2.1创建新模型启动ADINA:双击桌面图标或从开始菜单启动。选择新模型:在菜单栏中选择File>New。定义模型类型:选择结构分析、流体分析或耦合分析。1.3.2.2导入几何模型选择导入:在菜单栏中选择File>Import。支持格式:ADINA支持多种格式，如IGES、STEP、STL等。导入模型:选择几何模型文件并导入。1.3.2.3材料属性设置选择材料:在模型树中选择需要设置材料的实体。定义材料属性:在属性面板中输入材料的弹性模量、泊松比等参数。应用材料:点击应用按钮，将材料属性应用到所选实体。1.3.2.4网格划分选择网格类型:在菜单栏中选择Mesh>MeshType。设置网格参数:调整网格大小、精度等参数。生成网格:点击Mesh>Generate生成网格。1.3.2.5边界条件与载荷设置边界条件:在模型树中选择实体，然后在菜单栏中选择BoundaryConditions。应用载荷:选择实体，然后在菜单栏中选择Loads，输入载荷值。1.3.2.6运行分析选择分析类型:在菜单栏中选择Analysis>NonlinearStatic。设置分析参数:调整分析的步数、收敛准则等。运行分析:点击Analysis>Run开始分析。1.3.2.7查看结果结果可视化:在菜单栏中选择Results>Visualize。分析报告:选择Results>Report生成分析报告。1.3.3示例：创建一个简单的梁模型并进行非线性静力分析1.3.3.1步骤1:创建新模型启动ADINA，选择结构分析。1.3.3.2步骤2:定义几何使用内置的几何工具创建一个矩形梁。1.3.3.3步骤3:设置材料属性选择梁实体，定义材料为钢，弹性模量200GPa，泊松比0.3。1.3.3.4步骤4:网格划分选择`Mesh`>`MeshType`，设置为四面体网格，然后生成网格。1.3.3.5步骤5:应用边界条件与载荷在梁的一端设置固定边界条件，在另一端应用垂直向下的载荷。1.3.3.6步骤6:运行非线性静力分析选择`Analysis`>`NonlinearStatic`，设置分析步数为10，然后运行分析。1.3.3.7步骤7:查看结果在`Results`>`Visualize`中查看梁的变形和应力分布。通过以上步骤，用户可以完成一个简单的梁模型的非线性静力分析，理解ADINA的基本操作流程。2非线性静力分析基础2.1非线性力学概念在工程分析中，线性力学假设材料的应力与应变之间存在线性关系，且结构的变形不会显著影响其刚度。然而，在许多实际应用中，这些假设可能不成立，导致需要进行非线性分析。非线性力学涉及结构响应的复杂性，包括材料非线性、几何非线性和边界条件非线性。2.1.1材料非线性材料非线性指的是材料的应力-应变关系不再遵循线性比例。例如，金属在塑性变形阶段、混凝土在受压时、橡胶在大变形时，都会表现出非线性特性。2.1.2几何非线性几何非线性考虑了结构变形对分析结果的影响。当结构的变形足够大，以至于不能忽略其对结构刚度的影响时，就需要使用几何非线性分析。这在大位移、大旋转或接触问题中尤为重要。2.2材料非线性介绍材料非线性分析在ADINA中通过定义材料属性来实现。ADINA支持多种材料模型，包括弹性、塑性、粘弹性、超弹性等。2.2.1弹塑性材料模型弹塑性材料模型是ADINA中最常用的非线性材料模型之一。它描述了材料在弹性阶段和塑性阶段的行为。在弹性阶段，应力与应变成正比；在塑性阶段，材料继续变形，但应力可能保持不变或缓慢增加。2.2.1.1示例假设我们有一个简单的弹塑性材料模型，其弹性模量为200GPa，泊松比为0.3，屈服强度为250MPa。在ADINA中，可以使用以下输入文件定义这种材料：MATERIAL1

TYPEELASTICPLASTIC

E200000

NU0.3

SIGY250

ENDMATERIAL2.3几何非线性原理几何非线性分析考虑了结构变形对分析结果的影响。在ADINA中，当结构的位移或旋转足够大时，可以激活几何非线性分析。这通常通过在分析设置中选择适当的非线性选项来实现。2.3.1大位移和大旋转大位移和大旋转分析是几何非线性分析的一部分，它考虑了结构在大变形下的行为。在这些情况下，结构的初始几何和最终几何之间的差异可能很大，不能简单地用小变形理论来描述。2.3.2接触问题接触分析是几何非线性分析的另一个重要方面。当两个或多个物体接触时，接触面的变形和压力分布可能非常复杂，需要使用非线性分析来准确预测。2.3.2.1示例考虑一个简单的接触问题，其中两个物体在接触面上相互作用。在ADINA中，可以使用以下输入文件定义接触条件：CONTACT

SURFACE1

TYPESLIDING

BODY1

SURFACE2

BODY2

ENDSURFACE

ENDCONTACT在这个例子中，SURFACE1和SURFACE2是接触的两个表面，BODY1和BODY2是与这些表面相关的物体。TYPESLIDING指定了接触类型为滑动接触。2.4非线性静力分析流程进行非线性静力分析时，通常遵循以下步骤：定义材料属性：根据材料的非线性特性，选择合适的材料模型并定义其参数。设置几何非线性：如果结构的变形足够大，需要在分析设置中激活几何非线性选项。定义接触条件：对于涉及接触的问题，需要定义接触表面和接触类型。施加载荷和边界条件：根据问题的物理特性，施加适当的载荷和边界条件。选择求解器设置：非线性分析可能需要使用增量迭代求解器，以逐步逼近最终解。运行分析：执行非线性静力分析，ADINA将计算结构在非线性条件下的响应。后处理和结果分析：分析结果，检查应力、应变、位移等，确保分析的准确性和合理性。通过以上步骤，可以使用ADINA进行复杂的非线性静力分析，为工程设计和优化提供关键信息。3ADINA中的非线性静力分析设置3.1定义非线性材料属性在ADINA中进行非线性静力分析，首先需要定义材料的非线性属性。非线性材料属性可以包括塑性、蠕变、超弹性等特性。以塑性材料为例，我们可以通过定义材料的应力-应变关系来模拟材料在大应力下的非线性行为。3.1.1示例：定义塑性材料假设我们正在分析一个结构件，其材料为钢，具有理想的弹塑性行为。在ADINA中，可以通过以下步骤定义这种材料：选择材料类型：在材料属性定义中选择“塑性”。输入弹性模量和泊松比：这是材料的线性弹性属性。定义屈服强度：对于理想弹塑性材料，需要输入材料的屈服强度。设置硬化类型：理想弹塑性材料通常假设为“理想硬化”或“完全硬化”。3.1.1.1数据样例弹性模量：E泊松比：ν屈服强度：σ3.2设置几何非线性条件几何非线性分析考虑了结构变形对分析结果的影响，尤其在大变形或大位移情况下。在ADINA中，几何非线性可以通过选择适当的分析类型来激活。3.2.1激活几何非线性在ADINA的分析设置中，选择“非线性静力分析”，并确保勾选“考虑几何非线性”。3.3应用非线性载荷与边界条件非线性载荷与边界条件的设置是确保分析准确性的关键。在ADINA中，可以施加各种类型的载荷，包括力、压力、温度载荷等，并可以定义随时间变化的载荷。3.3.1示例：应用非线性载荷假设我们正在分析一个承受逐渐增加的力的结构，可以按照以下步骤设置载荷：选择载荷类型：在载荷定义中选择“力”。定义载荷大小：输入力的大小，例如F=设置载荷步：定义载荷随时间的变化，例如，从0到1000N，分10步增加。3.3.1.1数据样例初始力：F最终力：F载荷步数：N3.3.2示例代码;ADINAScriptforNonlinearStaticAnalysis

;DefineMaterialProperties

MAT1

TYPEPLASTIC

E200e3

NU0.3

SIGY250

HARDENIDEAL

ENDMAT

;SetNonlinearGeometryOption

ANALYSISNONLINEAR

GEOMETRYNONLINEAR

;ApplyNonlinearLoad

LOAD1

TYPEFORCE

VALUE0

ENDLOAD

LOAD2

TYPEFORCE

VALUE1000

STEP10

ENDLOAD

;DefineBoundaryConditions

BC1

TYPEFIXED

NODES123

DOF123

ENDBC3.3.3代码解释MAT1：定义材料属性，类型为塑性。E200e3：设置弹性模量为200GNU0.3：设置泊松比为0.3。SIGY250：定义屈服强度为250MHARDENIDEAL：设置硬化类型为理想硬化。ANALYSISNONLINEAR：选择非线性静力分析。GEOMETRYNONLINEAR：激活几何非线性。LOAD1和LOAD2：定义载荷，从0N逐渐增加到1000N，共10步。BC1：定义边界条件，固定节点1、2、3的所有自由度。通过以上步骤，我们可以在ADINA中设置一个非线性静力分析，考虑材料的塑性行为、几何非线性以及非线性载荷的影响。这将帮助我们更准确地预测结构在复杂载荷条件下的响应。4非线性静力分析案例研究4.1简单梁的非线性弯曲在非线性静力分析中，简单梁的非线性弯曲是一个基础但重要的案例。非线性行为可能由材料非线性、几何非线性和接触条件引起。对于简单梁，我们主要关注材料非线性和几何非线性。4.1.1材料非线性材料非线性通常指材料的应力-应变关系不再遵循线性关系。例如，钢材在超过屈服点后，其应力-应变曲线会表现出明显的非线性特征。在ADINA中，可以通过定义材料属性来模拟这种非线性行为。4.1.2几何非线性几何非线性发生在结构的变形足够大，以至于不能忽略变形对结构刚度的影响。在简单梁的弯曲中，当梁的挠度较大时，梁的中性轴会发生偏移，这将影响梁的刚度，从而导致非线性响应。4.1.3案例描述假设我们有一根长度为10米的简单梁，两端固定，中间受到垂直向下的集中力作用。梁的截面为矩形，宽度为0.2米，高度为0.1米。材料为钢材，弹性模量为200GPa，泊松比为0.3，屈服强度为250MPa。我们将使用ADINA进行非线性静力分析，以研究梁的非线性弯曲行为。4.1.4ADINA操作步骤建立模型：在ADINA中创建梁的几何模型，定义材料属性和边界条件。网格划分：对梁进行网格划分，确保网格足够细以捕捉非线性行为。加载：在梁的中间位置施加垂直向下的集中力。求解：设置非线性静力分析，求解梁的变形和应力分布。4.2复合材料板的压屈分析复合材料因其高比强度和比刚度，在航空航天、汽车和建筑领域得到广泛应用。然而，复合材料的非线性行为，特别是在压缩载荷下的压屈分析，是设计和分析中的关键问题。4.2.1压屈分析原理压屈分析（BucklingAnalysis）用于评估结构在压缩载荷作用下发生失稳的临界载荷。对于复合材料板，由于其各向异性，压屈分析更为复杂，需要考虑材料的非线性以及层间效应。4.2.2案例描述考虑一块由多层复合材料组成的矩形板，尺寸为1米×1米，厚度为0.01米。板的材料为碳纤维增强塑料（CFRP），每层的弹性模量、泊松比和厚度不同。板的四周固定，受到垂直向下的均匀压缩载荷。我们将使用ADINA进行压屈分析，以确定板的临界压缩载荷。4.2.3ADINA操作步骤建立模型：在ADINA中创建复合材料板的几何模型，定义各层的材料属性和厚度。网格划分：对板进行网格划分，确保网格能够准确反映各层的材料特性。加载：在板的上表面施加垂直向下的均匀压缩载荷。求解：设置压屈分析，求解板的临界压缩载荷和失稳模式。4.3混凝土结构的非线性响应混凝土是一种广泛使用的建筑材料，其非线性行为在结构分析中至关重要。混凝土的非线性响应包括塑性、裂缝和损伤等现象，这些都会影响结构的承载能力和安全性。4.3.1混凝土非线性响应原理混凝土的非线性响应主要由其复杂的材料性质决定。在受压时，混凝土表现出塑性行为；在受拉时，混凝土容易产生裂缝。此外，混凝土的损伤累积也会影响其长期性能。4.3.2案例描述假设我们有一座混凝土桥梁，桥面宽度为10米，长度为50米，桥墩高度为10米。桥梁受到车辆载荷和风载荷的作用。我们将使用ADINA进行非线性静力分析，以研究桥梁在这些载荷作用下的非线性响应。4.3.3ADINA操作步骤建立模型：在ADINA中创建桥梁的几何模型，定义混凝土的材料属性。网格划分：对桥梁进行网格划分，确保网格能够捕捉混凝土的裂缝和损伤行为。加载：在桥梁上施加车辆载荷和风载荷。求解：设置非线性静力分析，求解桥梁的变形、应力分布和损伤累积。4.3.4注意事项在进行混凝土结构的非线性分析时，需要特别注意以下几点：-材料模型：选择合适的混凝土材料模型，如弹塑性模型或损伤模型。-裂缝模拟：使用裂缝追踪技术来模拟混凝土的裂缝发展。-损伤累积：考虑损伤累积对结构性能的影响，特别是在长期载荷作用下。以上案例研究展示了ADINA在非线性静力分析中的应用，包括简单梁的非线性弯曲、复合材料板的压屈分析和混凝土结构的非线性响应。通过这些案例，可以深入了解非线性行为对结构性能的影响，以及如何使用ADINA进行有效的非线性静力分析。5高级非线性静力分析技巧5.1接触分析的设置与解读在进行非线性静力分析时，接触分析是关键的一部分，尤其是在处理结构件之间的相互作用时。ADINA提供了强大的接触分析功能，能够模拟各种接触条件，包括滑动、摩擦、间隙等。5.1.1设置接触分析在ADINA中设置接触分析，首先需要定义接触对，即哪些表面之间可能发生接触。这通常在前处理阶段完成，通过选择主表面（MasterSurface）和从表面（SlaveSurface）来定义接触对。主表面和从表面的选择基于物理接触的性质和分析需求。5.1.1.1示例假设我们有一个简单的模型，包含一个压板和一个底座，压板将接触并施力于底座上。在ADINA中，接触分析的设置可能如下：```plaintext*CONTACT1,2,0.3,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0.0,0