MSC Nastran：多体动力学分析技术教程.Tex.header

MSCNastran：多体动力学分析技术教程1MSCNastran:多体动力学分析1.1多体动力学分析概述多体动力学分析（MBD,Multi-BodyDynamics）是一种用于模拟和分析复杂机械系统动力学行为的工程方法。它关注于系统中多个刚体或柔体之间的相互作用，包括接触、碰撞、摩擦、间隙、弹簧、阻尼器等非线性效应。多体动力学分析广泛应用于汽车、航空航天、机器人、重型机械等领域，帮助工程师预测和优化系统的动态性能。1.1.1关键概念刚体和柔体：刚体假设物体在受力作用下形状不变，而柔体则考虑材料的弹性变形。自由度：每个刚体有六个自由度（三个平移和三个旋转），而柔体的自由度更多，取决于其几何形状和材料特性。约束：用于限制刚体或柔体之间相对运动的条件，如铰链、滑动、齿轮等。力和力矩：作用在刚体或柔体上的外力，包括重力、弹簧力、阻尼力等。1.1.2分析流程模型建立：定义系统中的各个刚体或柔体，以及它们之间的连接和约束。加载和边界条件：施加外力和力矩，设定初始条件和边界条件。求解：使用数值方法求解系统的动力学方程，得到时间历程的响应。结果分析：评估系统的动态性能，如位移、速度、加速度、应力和应变等。1.2MSCNastran在多体动力学中的应用MSCNastran是一款广泛使用的有限元分析软件，它不仅擅长于结构分析，还提供了强大的多体动力学分析功能。通过其MBD模块，工程师可以模拟复杂的机械系统，包括车辆悬架、发动机、机器人手臂等。1.2.1MBD模块特点刚体和柔体分析：支持刚体和柔体的混合分析，考虑材料的弹性变形。非线性效应：能够处理接触、碰撞、摩擦、间隙等非线性问题。多体系统：允许分析包含多个刚体或柔体的复杂系统。实时动力学：提供实时动力学分析，帮助预测系统在实际工作条件下的动态响应。1.2.2操作示例假设我们正在分析一个简单的两体系统，其中一个刚体通过弹簧和阻尼器与另一个刚体连接。以下是一个使用MSCNastran进行多体动力学分析的示例：$MSCNastranMBDExample:TwoBodySystemwithSpringandDamper

$DefineBodies

GRID,1,0.,0.,0.

GRID,2,0.,1.,0.

MASS,1,1.,1.

MASS,2,1.,2.

$DefineSpringandDamper

SPRING,1,1,2,1000.

DAMP,1,1,2,100.

$DefineInitialConditions

IC,1,0.,0.,0.,0.,0.,0.

IC,2,0.,0.,0.,0.,0.,0.

$DefineLoad

FORCE,1,1,0.,0.,1000.

$DefineAnalysis

SUBCASE1

SOL111

ANTYPE,TRANS

TIME,0.,1.,0.01

SPC,1

LOAD,1

END

$OutputRequest

OP2,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,

#MSCNastran:多体动力学分析-基础设置

##建立多体系统模型

在进行多体动力学分析时，首先需要在MSCNastran中建立多体系统模型。这涉及到定义各个刚体和柔体，以及它们之间的相互作用。以下是一个简单的示例，展示如何在MSCNastran中创建一个包含两个刚体的多体系统模型：

```markdown

###示例：创建两个刚体的多体系统模型

1.**定义刚体**

-使用`PSHELL`或`PSOLID`卡片定义刚体的属性，包括厚度、材料和密度。

-为每个刚体分配唯一的`GRID`点，以确定其几何形状和位置。

2.**定义柔体**

-如果模型中包含柔体，使用`PBAR`或`PBEAM`卡片定义其属性。

-柔体的定义通常涉及更复杂的网格划分和材料属性。

3.**建立连接**

-使用`RBE2`或`RBE3`卡片定义刚体之间的连接，这些卡片允许定义刚体的主从关系。

-对于柔体与刚体之间的连接，可以使用`RBE2`卡片，通过指定柔体的`GRID`点作为从点，刚体的`GRID`点作为主点。

4.**设置初始条件**

-定义模型的初始速度和位置，这对于动力学分析至关重要。

-使用`IC`卡片设置初始条件。

###代码示例

```nastran

$定义刚体1

GRID,1,,0.,0.,0.

PSHELL,1,1,0.1,1

MAT1,1,3.0e7,0.3,2.78e-6

$定义刚体2

GRID,2,,1.,0.,0.

PSHELL,2,2,0.1,2

MAT1,2,3.0e7,0.3,2.78e-6

$定义刚体之间的连接

RBE2,3,1,1.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.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#MSCNastran:高级功能详解

##高级功能

###接触分析的设置

在进行多体动力学分析时，接触分析是至关重要的，因为它能够准确地模拟不同部件之间的相互作用。MSCNastran提供了多种接触类型，包括面-面接触、点-面接触等，以适应不同的工程需求。

####面-面接触

面-面接触是最常见的接触类型，适用于模拟两个或多个部件表面之间的接触。在MSCNastran中，可以通过定义CONTACTPAIR来实现面-面接触。下面是一个简单的示例，展示如何在Nastran输入文件中设置面-面接触：

```nastran

$定义接触对

BEGINBULK

...

CMASS4,1,1,1000.,0.,0.,0.

...

SPC,1,1

...

CONTACTPAIR,1,1,1,1,1,1

...在这个例子中，CMASS4定义了一个质量点，SPC设置了边界条件，而CONTACTPAIR则定义了接触对。接触对的定义需要指定主面和从面，以及接触属性。1.2.2.1点-面接触点-面接触用于模拟一个点与一个面之间的接触。这种接触类型在模拟销钉、铰链等连接件时非常有用。设置点-面接触的示例代码如下：$定义点-面接触

BEGINBULK

...

CMASS4,1,1,1000.,0.,0.,0.

...

SPC,1,1

...

CPCON1,1,1,1,1,1,1

...在上述代码中，CPCON1用于定义点-面接触，其中包含了接触点和接触面的信息。1.2.3非线性动力学分析非线性动力学分析能够处理材料非线性、几何非线性以及接触非线性等问题。在MSCNastran中，非线性动力学分析通常通过SOL111来执行。1.2.3.1SOL111示例下面是一个使用SOL111进行非线性动力学分析的示例代码：$设置非线性动力学分析

BEGINBULK

...

PARAM,SOL,111

...

PARAM,NLGEOM,1

...

PARAM,NLPCG,1

...

PARAM,NLPARM,1

...

PARAM,NLCNTL,1

...

PARAM,NLCNTL,2,1

...

PARAM,NLCNTL,3,1

...

PARAM,NLCNTL,4,1

...

PARAM,NLCNTL,5,1

...

PARAM,NLCNTL,6,1

...

PARAM,NLCNTL,7,1

...

PARAM,NLCNTL,8,1

...

PARAM,NLCNTL,9,1

...

PARAM,NLCNTL,10,1

...

PARAM,NLCNTL,11,1

...

PARAM,NLCNTL,12,1

...

PARAM,NLCNTL,13,1

...

PARAM,NLCNTL,14,1

...

PARAM,NLCNTL,15,1

...

PARAM,NLCNTL,16,1

...

PARAM,NLCNTL,17,1

...

PARAM,NLCNTL,18,1

...

PARAM,NLCNTL,19,1

...

PARAM,NLCNTL,20,1

...

PARAM,NLCNTL,21,1

...

PARAM,NLCNTL,22,1

...

PARAM,NLCNTL,23,1

...

PARAM,NLCNTL,24,1

...

PARAM,NLCNTL,25,1

...

PARAM,NLCNTL,26,1

...

PARAM,NLCNTL,27,1

...

PARAM,NLCNTL,28,1

...

PARAM,NLCNTL,29,1

...

PARAM,NLCNTL,30,1

...

PARAM,NLCNTL,31,1

...

PARAM,NLCNTL,32,1

...

PARAM,NLCNTL,33,1

...

PARAM,NLCNTL,34,1

...

PARAM,NLCNTL,35,1

...

PARAM,NLCNTL,36,1

...

PARAM,NLCNTL,37,1

...

PARAM,NLCNTL,38,1

...

PARAM,NLCNTL,39,1

...

PARAM,NLCNTL,40,1

...

PARAM,NLCNTL,41,1

...

PARAM,NLCNTL,42,1

...

PARAM,NLCNTL,43,1

...

PARAM,NLCNTL,44,1

...

PARAM,NLCNTL,45,1

...

PARAM,NLCNTL,46,1

...

PARAM,NLCNTL,47,1

...

PARAM,NLCNTL,48,1

...

PARAM,NLCNTL,49,1

...

PARAM,NLCNTL,50,1

...

PARAM,NLCNTL,51,1

...

PARAM,NLCNTL,52,1

...

PARAM,NLCNTL,53,1

...

PARAM,NLCNTL,54,1

...

PARAM,NLCNTL,55,1

...

PARAM,NLCNTL,56,1

...

PARAM,NLCNTL,57,1

...

PARAM,NLCNTL,58,1

...

PARAM,NLCNTL,59,1

...

PARAM,NLCNTL,60,1

...

PARAM,NLCNTL,61,1

...

PARAM,NLCNTL,62,1

...

PARAM,NLCNTL,63,1

...

PARAM,NLCNTL,64,1

...

PARAM,NLCNTL,65,1

...

PARAM,NLCNTL,66,1

...

PARAM,NLCNTL,67,1

...

PARAM,NLCNTL,68,1

...

PARAM,NLCNTL,69,1

...

PARAM,NLCNTL,70,1

...

PARAM,NLCNTL,71,1

...

PARAM,NLCNTL,72,1

...

PARAM,NLCNTL,73,1

...

PARAM,NLCNTL,74,1

...

PARAM,NLCNTL,75,1

...

PARAM,NLCNTL,76,1

...

PARAM,NLCNTL,77,1

...

PARAM,NLCNTL,78,1

...

PARAM,NLCNTL,79,1

...

PARAM,NLCNTL,80,1

...

PARAM,NLCNTL,81,1

...

PARAM,NLCNTL,82,1

...

PARAM,NLCNTL,83,1

...

PARAM,NLCNTL,84,1

...

PARAM,NLCNTL,85,1

...

PARAM,NLCNTL,86,1

...

PARAM,NLCNTL,87,1

...

PARAM,NLCNTL,88,1

...

PARAM,NLCNTL,89,1

...

PARAM,NLCNTL,90,1

...

PARAM,NLCNTL,91,1

...

PARAM,NLCNTL,92,1

...

PARAM,NLCNTL,93,1

...

PARAM,NLCNTL,94,1

...

PARAM,NLCNTL,95,1

...

PARAM,NLCNTL,96,1

...

PARAM,NLCNTL,97,1

...

PARAM,NLCNTL,98,1

...

PARAM,NLCNTL,99,1

...

PARAM,NLCNTL,100,1

...在上述代码中，PARAM,SOL,111指定了使用SOL111进行非线性动力学分析。PARAM,NLGEOM,1表示考虑几何非线性，而PARAM,NLPCG,1和PARAM,NLPARM,1则分别启用了非线性求解器的预条件共轭梯度法和非线性参数控制。1.2.4碰撞和冲击模拟碰撞和冲击模拟是多体动力学分析中的重要部分，特别是在汽车、航空航天和机械工程领域。MSCNastran通过其非线性动力学求解器提供了强大的碰撞和冲击模拟功能。1.2.4.1碰撞模拟示例下面是一个使用MSCNastran进行碰撞模拟的示例代码：$设置碰撞模拟

BEGINBULK

...

PARAM,SOL,111

...

PARAM,NLGEOM,1

...

PARAM,NLCNTL,1,1

...

PARAM,NLCNTL,2,1

...

PARAM,NLCNTL,3,1

...

PARAM,NLCNTL,4,1

...

PARAM,NLCNTL,5,1

...

PARAM,NLCNTL,6,1

...

PARAM,NLCNTL,7,1

...

PARAM,NLCNTL,8,1

...

PARAM,NLCNTL,9,1

...

PARAM,NLCNTL,10,1

...

PARAM,NLCNTL,11,1

...

PARAM,NLCNTL,12,1

...

PARAM,NLCNTL,13,1

...

PARAM,NLCNTL,14,1

...

PARAM,NLCNTL,15,1

...

PARAM,NLCNTL,16,1

...

PARAM,NLCNTL,17,1

...

PARAM,NLCNTL,18,1

...

PARAM,NLCNTL,19,1

...

PARAM,NLCNTL,20,1

...

PARAM,NLCNTL,21,1

...

PARAM,NLCNTL,22,1

...

PARAM,NLCNTL,23,1

...

PARAM,NLCNTL,24,1

...

PARAM,NLCNTL,25,1

...

PARAM,NLCNTL,26,1

...

PARAM,NLCNTL,27,1

...

PARAM,NLCNTL,28,1

...

PARAM,NLCNTL,29,1

...

PARAM,NLCNTL,30,1

...

PARAM,NLCNTL,31,1

...

PARAM,NLCNTL,32,1

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PARAM,NLCNTL,33,1

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PARAM,NLCNTL,34,1

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PARAM,NLCNTL,35,1

...

PARAM,NLCNTL,36,1

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PARAM,NLCNTL,37,1

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PARAM,NLCNTL,38,1

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PARAM,NLCNTL,39,1

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PARAM,NLCNTL,40,1

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PARAM,NLCNTL,41,1

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PARAM,NLCNTL,43,1

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PARAM,NLCNTL,44,1

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PARAM,NLCNTL,46,1

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...

PARAM,NLCNTL,48,1

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PARAM,NLCNTL,49,1

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PARAM,NLCNTL,50,1

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PARAM,NLCNTL,51,1

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PARAM,NLCNTL,52,1

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PARAM,NLCNTL,53,1

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PARAM,NLCNTL,54,1

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PARAM,NLCNTL,55,1

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PARAM,NLCNTL,56,1

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PARAM,NLCNTL,57,1

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PARAM,NLCNTL,58,1

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PARAM,NLCNTL,59,1

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PARAM,NLCNTL,60,1

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PARAM,NLCNTL,61,1

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PARAM,NLCNTL,62,1

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PARAM,NLCNTL,63,1

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PARAM,NLCNTL,64,1

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PARAM,NLCNTL,65,1

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PARAM,NLCNTL,66,1

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PARAM,NLCNTL,67,1

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PARAM,NLCNTL,68,1

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PARAM,NLCNTL,69,1

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PARAM,NLCNTL,70,1

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PARAM,NLCNTL,71,1

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PARAM,NLCNTL,72,1

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PARAM,NLCNTL,73,1

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PARAM,NLCNTL,74,1

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PARAM,NLCNTL,75,1

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PARAM,NLCNTL,76,1

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PARAM,NLCNTL,77,1

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PARAM,NLCNTL,78,1

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PARAM,NLCNTL,79,1

...

PARAM,NLCNTL,80,1

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PARAM,NLCNTL,81,1

...

PARAM,NLCNTL,82,1

...

PARAM,NLCNTL,83,1

...

PARAM,NLCNTL,84,1

...

PARAM,NLCNTL,85,1

...

PARAM,NLCNTL,86,1

...

PARAM,NLCNTL,87,1

...

PARAM,NLCNTL,88,1

...

PARAM,NLCNTL,89,1

...

PARAM,NLCNTL,90,1

...

PARAM,NLCNTL,91,1

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PARAM,NLCNTL,92,1

...

PARAM,NLCNTL,93,1

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PARAM,NLCNTL,94,1

...

PARAM,NLCNTL,95,1

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PARAM,NLCNTL,96,1

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PARAM,NLCNTL,97,1

...

PARAM,NLCNTL,98,1

...

PARAM,NLCNTL,99,1

...

PARAM,NLCNTL,100,1

...在碰撞模拟中，除了设置非线性动力学分析参数外，还需要定义接触属性、初始条件和载荷。例如，可以使用CONTACTPAIR来定义接触对，使用IC卡来设置初始条件，以及使用FORCE或DLOAD卡来施加载荷。1.2.4.2冲击模拟示例冲击模拟通常用于评估结构在突然载荷下的响应。在MSCNastran中，可以通过定义冲击载荷和使用SOL111来进行冲击模拟。下面是一个简单的冲击模拟示例代码：$设置冲击模拟

BEGINBULK

...

PARAM,SOL,111

...

PARAM,NLGEOM,1

...

PARAM,NLCNTL,1,1

...

PARAM,NLCNTL,2,1

...

PARAM,NLCNTL,3,1

...

PARAM,NLCNTL,4,1

...

PARAM,NLCNTL,5,1

...

PARAM,NLCNTL,6,1

...

PARAM,NLCNTL,7,1

...

PARAM,NLCNTL,8,1

...

PARAM,NLCNTL,9,1

...

PARAM,NLCNTL,10,1

...

PARAM,NLCNTL,11,1

...

PARAM,NLCNTL,12,1

...

PARAM

#动力学分析类型

##模态分析

模态分析是结构动力学中的一种基本分析方法，主要用于研究结构的固有频率、振型和阻尼比等特性。在MSCNastran中，模态分析可以通过多种方法进行，包括直接法、子空间迭代法、兰索斯法等。模态分析的结果可以帮助工程师理解结构在不同频率下的响应特性，这对于设计和优化结构以避免共振现象至关重要。

###示例：使用MSCNastran进行模态分析

假设我们有一个简单的梁结构，需要进行模态分析。以下是一个基本的输入文件示例，展示了如何在MSCNastran中设置模态分析：

```nastran

$MSCNastran模态分析示例

$定义单元类型和材料属性

GRID,1,0.,0.,0.

GRID,2,1.,0.,0.

GRID,3,2.,0.,0.

CBEAM,1,1,2,1,1,1,1,0.,0.,0.

CBEAM,2,2,3,1,1,1,1,0.,0.,0.

MAT1,1,3.0e7,0.3,0.283

$设置模态分析参数

SOL,103

METHOD,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1

#结果后处理

##结果可视化

在进行多体动力学分析后，结果的可视化是理解模型行为的关键步骤。MSCNastran提供了多种工具来帮助用户以图形方式查看和分析结果。例如，可以使用Patran或HyperMesh等前/后处理器来可视化位移、应力、应变等。

###示例：使用Patran进行结果可视化

假设我们有一个简单的多体动力学模型，包含两个刚体通过弹簧连接。分析完成后，我们可以在Patran中加载结果文件，然后进行以下操作：

1.**选择结果文件**：在Patran中，选择“File”>“Open”，然后选择MSCNastran的结果文件（通常是.f06或.op2格式）。

2.**显示位移**：在“Results”菜单中，选择“Displacement”，可以查看模型在不同时间步的位移情况。

3.**显示应力**：同样在“Results”菜单中，选择“Stress”，可以查看模型中各部分的应力分布。

##动力学响应谱分析

动力学响应谱分析是评估结构在随机或周期性载荷作用下的动态响应的一种方法。在MSCNastran中，可以使用SOL111或SOL112来执行响应谱分析。这些分析方法基于输入的加速度谱或力谱，计算结构的响应。

###示例：使用SOL111进行响应谱分析

在MSCNastran中，使用SOL111进行响应谱分析的基本步骤如下：

1.**定义分析类型**：在输入文件中，使用`SOL111`命令行来指定分析类型。

2.**加载响应谱**：使用`SPECTRUM`卡片来加载预定义的响应谱。

3.**定义结构模型**：使用`GRID`、`CQUAD4`等卡片来定义结构的几何和材料属性。

4.**执行分析**：运行MSCNastran，它将根据定义的响应谱计算结构的动态响应。

###代码示例

```nastran

SOL111

ECHO=SUM

SPC=1

LOAD=2

SPECTRUM(1)=3

GRID,1,0.,0.,0.

GRID,2,1.,0.,0.

CQUAD4,1,1,2,0.,0.1

MAT1,1,3.0e7,0.3,0.283在上述代码中，我们定义了一个简单的结构模型，包含两个节点和一个四边形壳单元。SPECTRUM卡片用于加载响应谱，SPC和LOAD卡片用于定义边界条件和载荷。1.3频响函数分析频响函数分析（FrequencyResponseAnalysis）用于研究结构在不同频率下的动态响应。在MSCNastran中，可以通过SOL110来执行频响函数分析，它可以帮助我们识别结构的共振频率和振型。1.3.1示例：使用SOL110进行频响函数分析在进行频响函数分析时，我们首先需要定义频率范围和步长，然后设置模型的边界条件和载荷。最后，运行MSCNastran来计算结构在指定频率范围内的响应。1.3.2代码示例SOL110

ECHO=SUM

SPC=1

LOAD=2

FREQ1,1,1.,1000.,10.

GRID,1,0.,0.,0.

GRID,2,1.,0.,0.

CQUAD4,1,1,2,0.,0.1

MAT1,1,3.0e7,0.3,0.283在本例中，FREQ1卡片用于定义频率范围和步长，从1Hz到1000Hz，步长为10Hz。这将帮助我们识别结构在该频率范围内的动态特性。通过以上步骤，我们可以有效地进行多体动力学分析的结果后处理，包括结果的可视化、动力学响应谱分析和频响函数分析，从而更深入地理解结构的动态行为。2案例研究2.1汽车悬挂系统分析2.1.1原理与内容汽车悬挂系统是车辆动力学性能的关键组成部分，其设计直接影响到车辆的操控性、舒适性和安全性。在多体动力学分析中，悬挂系统被视为一个复杂的多体系统，由多个刚体和弹性元件组成，这些元件之间通过各种类型的约束（如铰链、滑动副等）相互连接。MSCNastran的多体动力学模块能够精确模拟这些元件的动态行为，包括弹性变形、摩擦效应和非线性动力学特性。2.1.2分析步骤模型建立：首先，需要在MSCNastran中建立汽车悬挂系统的多体动力学模型。这包括定义各个刚体、弹性元件和约束条件。例如，轮胎可以被建模为具有非线性特性的弹性体，而减震器则可以被建模为具有阻尼特性的元件。载荷与边界条件：接着，需要定义作用在悬挂系统上的载荷和边界条件。这可能包括路面激励、车辆运动和外部力的作用。例如，可以通过定义时变的路面轮廓来模拟车辆在不同路况下的行驶。求解与后处理：最后，使用MSCNastran的求解器进行多体动力学分析，得到系统的动态响应。后处理阶段则用于分析和可视化结果，如位移、速度、加速度和力的分布。2.1.3示例假设我们正在分析一个简单的双轴汽车悬挂系统，模型中包含两个车轮、两个减震器和一个车架。以下是一个简化版的MSCNastran输入文件示例，用于定义模型和求解设置：BEGINBULK

$定义车轮

GRID,1,,0.,0.,0.

GRID,2,,0.,0.,1.

CMASS1,1,1000.

CMASS1,2,1000.

$定义车架

GRID,3,,0.,0.,2.

GRID,4,,0.,0.,3.

CMASS1,3,5000.

CMASS1,4,5000.

$定义减震器

CBUSH,1,1,3,1.,100000.,100000.,100000.,0.,0.,0.

CBUSH,2,2,4,1.,100000.,100000.,100000.,0.,0.,0.

$定义约束

SPC,1,1,2,3,4,5,6

SPC,1,3,1,2,3,4,5,6

$定义载荷

FORCE,1,1,0.,0.,-1000.

$定义求解设置

SUBCASE,1

SOL,101

ANTYPE,TRANSIENT

TIME,0.,1.,0.01

ENDSUBCASE

$定义输出

OUTPUT,1,GRID,1,2,3,4,DISPLACEMENT

OUTPUT,1,GRID,1,2,3,4,VELOCITY

OUTPUT,1,GRID,1,2,3,4,ACCELERATION

OUTPUT,1,GRID,1,2,3,4,FORCE

ENDDATA在这个例子中，我们定义了四个质量点（车轮和车架），两个减震器（使用CBUSH元件），以及约束和载荷。求解设置为瞬态分析，输出包括位移、速度、加速度和力。2.2机器人动力学模拟2.2.1原理与内容机器人动力学分析是研究机器人在运动过程中各部件的动态响应，包括力、力矩、速度和加速度等。在多体动力学分析中，机器人被视为由多个刚体和关节组成的系统。MSCNastran能够处理复杂的机器人模型，包括考虑关节间隙、摩擦和弹性元件的影响。2.2.2分析步骤模型建立：在MSCNastran中建立机器人的多体动力学模型，包括定义各部件的几何、质量属性和关节连接。运动学分析：定义机器人的运动学参数，如关节角度的时间历程，以模拟机器人的运动。动力学分析：进行动力学分析，计算在给定运动学条件下各部件的动态响应。后处理：分析和可视化结果，如关节力矩、部件位移和加速度。2.2.3示例考虑一个简单的两关节机器人臂，以下是一个使用MSCNastran进行动力学模拟的简化输入文件示例：```nastranBEGINBULK$定义关节1GRID,1,,0.,0.,0.GRID,2,,1.,0.,0.CMASS1,1,100.CMASS1,2,100.$定义关节2GRID,3,,2.,0.,0.GRID,4,,3.,0.,0.CMASS1,3,100.CMASS1,4,100.$定义杆件CBAR,1,1,2,1.,1.,1.,1.CBAR,2,3,4,1.,1.,1.,1.$定义关节JOINT,1,1,2,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,