MSC Nastran：多體動力學(xué)分析技術(shù)教程.Tex.header

MSCNastran：多體動力學(xué)分析技術(shù)教程1MSCNastran:多體動力學(xué)分析1.1多體動力學(xué)分析概述多體動力學(xué)分析（MBD,Multi-BodyDynamics）是一種用于模擬和分析復(fù)雜機械系統(tǒng)動力學(xué)行為的工程方法。它關(guān)注于系統(tǒng)中多個剛體或柔體之間的相互作用，包括接觸、碰撞、摩擦、間隙、彈簧、阻尼器等非線性效應(yīng)。多體動力學(xué)分析廣泛應(yīng)用于汽車、航空航天、機器人、重型機械等領(lǐng)域，幫助工程師預(yù)測和優(yōu)化系統(tǒng)的動態(tài)性能。1.1.1關(guān)鍵概念剛體和柔體：剛體假設(shè)物體在受力作用下形狀不變，而柔體則考慮材料的彈性變形。自由度：每個剛體有六個自由度（三個平移和三個旋轉(zhuǎn)），而柔體的自由度更多，取決于其幾何形狀和材料特性。約束：用于限制剛體或柔體之間相對運動的條件，如鉸鏈、滑動、齒輪等。力和力矩：作用在剛體或柔體上的外力，包括重力、彈簧力、阻尼力等。1.1.2分析流程模型建立：定義系統(tǒng)中的各個剛體或柔體，以及它們之間的連接和約束。加載和邊界條件：施加外力和力矩，設(shè)定初始條件和邊界條件。求解：使用數(shù)值方法求解系統(tǒng)的動力學(xué)方程，得到時間歷程的響應(yīng)。結(jié)果分析：評估系統(tǒng)的動態(tài)性能，如位移、速度、加速度、應(yīng)力和應(yīng)變等。1.2MSCNastran在多體動力學(xué)中的應(yīng)用MSCNastran是一款廣泛使用的有限元分析軟件，它不僅擅長于結(jié)構(gòu)分析，還提供了強大的多體動力學(xué)分析功能。通過其MBD模塊，工程師可以模擬復(fù)雜的機械系統(tǒng)，包括車輛懸架、發(fā)動機、機器人手臂等。1.2.1MBD模塊特點剛體和柔體分析：支持剛體和柔體的混合分析，考慮材料的彈性變形。非線性效應(yīng)：能夠處理接觸、碰撞、摩擦、間隙等非線性問題。多體系統(tǒng)：允許分析包含多個剛體或柔體的復(fù)雜系統(tǒng)。實時動力學(xué)：提供實時動力學(xué)分析，幫助預(yù)測系統(tǒng)在實際工作條件下的動態(tài)響應(yīng)。1.2.2操作示例假設(shè)我們正在分析一個簡單的兩體系統(tǒng)，其中一個剛體通過彈簧和阻尼器與另一個剛體連接。以下是一個使用MSCNastran進行多體動力學(xué)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:多體動力學(xué)分析-基礎(chǔ)設(shè)置

##建立多體系統(tǒng)模型

在進行多體動力學(xué)分析時，首先需要在MSCNastran中建立多體系統(tǒng)模型。這涉及到定義各個剛體和柔體，以及它們之間的相互作用。以下是一個簡單的示例，展示如何在MSCNastran中創(chuàng)建一個包含兩個剛體的多體系統(tǒng)模型：

```markdown

###示例：創(chuàng)建兩個剛體的多體系統(tǒng)模型

1.**定義剛體**

-使用`PSHELL`或`PSOLID`卡片定義剛體的屬性，包括厚度、材料和密度。

-為每個剛體分配唯一的`GRID`點，以確定其幾何形狀和位置。

2.**定義柔體**

-如果模型中包含柔體，使用`PBAR`或`PBEAM`卡片定義其屬性。

-柔體的定義通常涉及更復(fù)雜的網(wǎng)格劃分和材料屬性。

3.**建立連接**

-使用`RBE2`或`RBE3`卡片定義剛體之間的連接，這些卡片允許定義剛體的主從關(guān)系。

-對于柔體與剛體之間的連接，可以使用`RBE2`卡片，通過指定柔體的`GRID`點作為從點，剛體的`GRID`點作為主點。

4.**設(shè)置初始條件**

-定義模型的初始速度和位置，這對于動力學(xué)分析至關(guān)重要。

-使用`IC`卡片設(shè)置初始條件。

###代碼示例

```nastran

$定義剛體1

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

PSHELL,1,1,0.1,1

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

$定義剛體2

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

PSHELL,2,2,0.1,2

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

$定義剛體之間的連接

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:高級功能詳解

##高級功能

###接觸分析的設(shè)置

在進行多體動力學(xué)分析時，接觸分析是至關(guān)重要的，因為它能夠準(zhǔn)確地模擬不同部件之間的相互作用。MSCNastran提供了多種接觸類型，包括面-面接觸、點-面接觸等，以適應(yīng)不同的工程需求。

####面-面接觸

面-面接觸是最常見的接觸類型，適用于模擬兩個或多個部件表面之間的接觸。在MSCNastran中，可以通過定義CONTACTPAIR來實現(xiàn)面-面接觸。下面是一個簡單的示例，展示如何在Nastran輸入文件中設(shè)置面-面接觸：

```nastran

$定義接觸對

BEGINBULK

...

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

...

SPC,1,1

...

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

...在這個例子中，CMASS4定義了一個質(zhì)量點，SPC設(shè)置了邊界條件，而CONTACTPAIR則定義了接觸對。接觸對的定義需要指定主面和從面，以及接觸屬性。1.2.2.1點-面接觸點-面接觸用于模擬一個點與一個面之間的接觸。這種接觸類型在模擬銷釘、鉸鏈等連接件時非常有用。設(shè)置點-面接觸的示例代碼如下：$定義點-面接觸

BEGINBULK

...

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

...

SPC,1,1

...

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

...在上述代碼中，CPCON1用于定義點-面接觸，其中包含了接觸點和接觸面的信息。1.2.3非線性動力學(xué)分析非線性動力學(xué)分析能夠處理材料非線性、幾何非線性以及接觸非線性等問題。在MSCNastran中，非線性動力學(xué)分析通常通過SOL111來執(zhí)行。1.2.3.1SOL111示例下面是一個使用SOL111進行非線性動力學(xué)分析的示例代碼：$設(shè)置非線性動力學(xué)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

...在上述代碼中，PARAM,SOL,111指定了使用SOL111進行非線性動力學(xué)分析。PARAM,NLGEOM,1表示考慮幾何非線性，而PARAM,NLPCG,1和PARAM,NLPARM,1則分別啟用了非線性求解器的預(yù)條件共軛梯度法和非線性參數(shù)控制。1.2.4碰撞和沖擊模擬碰撞和沖擊模擬是多體動力學(xué)分析中的重要部分，特別是在汽車、航空航天和機械工程領(lǐng)域。MSCNastran通過其非線性動力學(xué)求解器提供了強大的碰撞和沖擊模擬功能。1.2.4.1碰撞模擬示例下面是一個使用MSCNastran進行碰撞模擬的示例代碼：$設(shè)置碰撞模擬

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

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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,40,1

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PARAM,NLCNTL,41,1

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PARAM,NLCNTL,42,1

...

PARAM,NLCNTL,43,1

...

PARAM,NLCNTL,44,1

...

PARAM,NLCNTL,45,1

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PARAM,NLCNTL,46,1

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PARAM,NLCNTL,47,1

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PARAM,NLCNTL,49,1

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PARAM,NLCNTL,53,1

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PARAM,NLCNTL,64,1

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PARAM,NLCNTL,68,1

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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

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PARAM,NLCNTL,80,1

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...

PARAM,NLCNTL,100,1

...在碰撞模擬中，除了設(shè)置非線性動力學(xué)分析參數(shù)外，還需要定義接觸屬性、初始條件和載荷。例如，可以使用CONTACTPAIR來定義接觸對，使用IC卡來設(shè)置初始條件，以及使用FORCE或DLOAD卡來施加載荷。1.2.4.2沖擊模擬示例沖擊模擬通常用于評估結(jié)構(gòu)在突然載荷下的響應(yīng)。在MSCNastran中，可以通過定義沖擊載荷和使用SOL111來進行沖擊模擬。下面是一個簡單的沖擊模擬示例代碼：$設(shè)置沖擊模擬

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

#動力學(xué)分析類型

##模態(tài)分析

模態(tài)分析是結(jié)構(gòu)動力學(xué)中的一種基本分析方法，主要用于研究結(jié)構(gòu)的固有頻率、振型和阻尼比等特性。在MSCNastran中，模態(tài)分析可以通過多種方法進行，包括直接法、子空間迭代法、蘭索斯法等。模態(tài)分析的結(jié)果可以幫助工程師理解結(jié)構(gòu)在不同頻率下的響應(yīng)特性，這對于設(shè)計和優(yōu)化結(jié)構(gòu)以避免共振現(xiàn)象至關(guān)重要。

###示例：使用MSCNastran進行模態(tài)分析

假設(shè)我們有一個簡單的梁結(jié)構(gòu)，需要進行模態(tài)分析。以下是一個基本的輸入文件示例，展示了如何在MSCNastran中設(shè)置模態(tài)分析：

```nastran

$MSCNastran模態(tài)分析示例

$定義單元類型和材料屬性

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

$設(shè)置模態(tài)分析參數(shù)

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

#結(jié)果后處理

##結(jié)果可視化

在進行多體動力學(xué)分析后，結(jié)果的可視化是理解模型行為的關(guān)鍵步驟。MSCNastran提供了多種工具來幫助用戶以圖形方式查看和分析結(jié)果。例如，可以使用Patran或HyperMesh等前/后處理器來可視化位移、應(yīng)力、應(yīng)變等。

###示例：使用Patran進行結(jié)果可視化

假設(shè)我們有一個簡單的多體動力學(xué)模型，包含兩個剛體通過彈簧連接。分析完成后，我們可以在Patran中加載結(jié)果文件，然后進行以下操作：

1.**選擇結(jié)果文件**：在Patran中，選擇“File”>“Open”，然后選擇MSCNastran的結(jié)果文件（通常是.f06或.op2格式）。

2.**顯示位移**：在“Results”菜單中，選擇“Displacement”，可以查看模型在不同時間步的位移情況。

3.**顯示應(yīng)力**：同樣在“Results”菜單中，選擇“Stress”，可以查看模型中各部分的應(yīng)力分布。

##動力學(xué)響應(yīng)譜分析

動力學(xué)響應(yīng)譜分析是評估結(jié)構(gòu)在隨機或周期性載荷作用下的動態(tài)響應(yīng)的一種方法。在MSCNastran中，可以使用SOL111或SOL112來執(zhí)行響應(yīng)譜分析。這些分析方法基于輸入的加速度譜或力譜，計算結(jié)構(gòu)的響應(yīng)。

###示例：使用SOL111進行響應(yīng)譜分析

在MSCNastran中，使用SOL111進行響應(yīng)譜分析的基本步驟如下：

1.**定義分析類型**：在輸入文件中，使用`SOL111`命令行來指定分析類型。

2.**加載響應(yīng)譜**：使用`SPECTRUM`卡片來加載預(yù)定義的響應(yīng)譜。

3.**定義結(jié)構(gòu)模型**：使用`GRID`、`CQUAD4`等卡片來定義結(jié)構(gòu)的幾何和材料屬性。

4.**執(zhí)行分析**：運行MSCNastran，它將根據(jù)定義的響應(yīng)譜計算結(jié)構(gòu)的動態(tài)響應(yīng)。

###代碼示例

```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在上述代碼中，我們定義了一個簡單的結(jié)構(gòu)模型，包含兩個節(jié)點和一個四邊形殼單元。SPECTRUM卡片用于加載響應(yīng)譜，SPC和LOAD卡片用于定義邊界條件和載荷。1.3頻響函數(shù)分析頻響函數(shù)分析（FrequencyResponseAnalysis）用于研究結(jié)構(gòu)在不同頻率下的動態(tài)響應(yīng)。在MSCNastran中，可以通過SOL110來執(zhí)行頻響函數(shù)分析，它可以幫助我們識別結(jié)構(gòu)的共振頻率和振型。1.3.1示例：使用SOL110進行頻響函數(shù)分析在進行頻響函數(shù)分析時，我們首先需要定義頻率范圍和步長，然后設(shè)置模型的邊界條件和載荷。最后，運行MSCNastran來計算結(jié)構(gòu)在指定頻率范圍內(nèi)的響應(yīng)。1.3.2代碼示例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，F(xiàn)REQ1卡片用于定義頻率范圍和步長，從1Hz到1000Hz，步長為10Hz。這將幫助我們識別結(jié)構(gòu)在該頻率范圍內(nèi)的動態(tài)特性。通過以上步驟，我們可以有效地進行多體動力學(xué)分析的結(jié)果后處理，包括結(jié)果的可視化、動力學(xué)響應(yīng)譜分析和頻響函數(shù)分析，從而更深入地理解結(jié)構(gòu)的動態(tài)行為。2案例研究2.1汽車懸掛系統(tǒng)分析2.1.1原理與內(nèi)容汽車懸掛系統(tǒng)是車輛動力學(xué)性能的關(guān)鍵組成部分，其設(shè)計直接影響到車輛的操控性、舒適性和安全性。在多體動力學(xué)分析中，懸掛系統(tǒng)被視為一個復(fù)雜的多體系統(tǒng)，由多個剛體和彈性元件組成，這些元件之間通過各種類型的約束（如鉸鏈、滑動副等）相互連接。MSCNastran的多體動力學(xué)模塊能夠精確模擬這些元件的動態(tài)行為，包括彈性變形、摩擦效應(yīng)和非線性動力學(xué)特性。2.1.2分析步驟模型建立：首先，需要在MSCNastran中建立汽車懸掛系統(tǒng)的多體動力學(xué)模型。這包括定義各個剛體、彈性元件和約束條件。例如，輪胎可以被建模為具有非線性特性的彈性體，而減震器則可以被建模為具有阻尼特性的元件。載荷與邊界條件：接著，需要定義作用在懸掛系統(tǒng)上的載荷和邊界條件。這可能包括路面激勵、車輛運動和外部力的作用。例如，可以通過定義時變的路面輪廓來模擬車輛在不同路況下的行駛。求解與后處理：最后，使用MSCNastran的求解器進行多體動力學(xué)分析，得到系統(tǒng)的動態(tài)響應(yīng)。后處理階段則用于分析和可視化結(jié)果，如位移、速度、加速度和力的分布。2.1.3示例假設(shè)我們正在分析一個簡單的雙軸汽車懸掛系統(tǒng)，模型中包含兩個車輪、兩個減震器和一個車架。以下是一個簡化版的MSCNastran輸入文件示例，用于定義模型和求解設(shè)置：BEGINBULK

$定義車輪

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

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

CMASS1,1,1000.

CMASS1,2,1000.

$定義車架

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

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

CMASS1,3,5000.

CMASS1,4,5000.

$定義減震器

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

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

$定義約束

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

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

$定義載荷

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

$定義求解設(shè)置

SUBCASE,1

SOL,101

ANTYPE,TRANSIENT

TIME,0.,1.,0.01

ENDSUBCASE

$定義輸出

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在這個例子中，我們定義了四個質(zhì)量點（車輪和車架），兩個減震器（使用CBUSH元件），以及約束和載荷。求解設(shè)置為瞬態(tài)分析，輸出包括位移、速度、加速度和力。2.2機器人動力學(xué)模擬2.2.1原理與內(nèi)容機器人動力學(xué)分析是研究機器人在運動過程中各部件的動態(tài)響應(yīng)，包括力、力矩、速度和加速度等。在多體動力學(xué)分析中，機器人被視為由多個剛體和關(guān)節(jié)組成的系統(tǒng)。MSCNastran能夠處理復(fù)雜的機器人模型，包括考慮關(guān)節(jié)間隙、摩擦和彈性元件的影響。2.2.2分析步驟模型建立：在MSCNastran中建立機器人的多體動力學(xué)模型，包括定義各部件的幾何、質(zhì)量屬性和關(guān)節(jié)連接。運動學(xué)分析：定義機器人的運動學(xué)參數(shù)，如關(guān)節(jié)角度的時間歷程，以模擬機器人的運動。動力學(xué)分析：進行動力學(xué)分析，計算在給定運動學(xué)條件下各部件的動態(tài)響應(yīng)。后處理：分析和可視化結(jié)果，如關(guān)節(jié)力矩、部件位移和加速度。2.2.3示例考慮一個簡單的兩關(guān)節(jié)機器人臂，以下是一個使用MSCNastran進行動力學(xué)模擬的簡化輸入文件示例：```nastranBEGINBULK$定義關(guān)節(jié)1GRID,1,,0.,0.,0.GRID,2,,1.,0.,0.CMASS1,1,100.CMASS1,2,100.$定義關(guān)節(jié)2GRID,3,,2.,0.,0.GRID,4,,3.,0.,0.CMASS1,3,100.CMASS1,4,100.$定義桿件CBAR,1,1,2,1.,1.,1.,1.CBAR,2,3,4,1.,1.,1.,1.$定義關(guān)節(jié)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.,