整车FEM建模手册-绝密

用于碰撞被动安全性

CAE

分析

FEM

建模手册

车身模型建模要求

一般要求

General Requirements

1. The parts shall be modelled using linear (3 or 4 noded) shell elements.

2. The parts shall be modelled on the mid surface. If the delivered geometry is

not a mid surface representation, the geometry shall be modified to represent

the mid surface.

3. No elements are allowed to cross the “symmetry” line y=0 (nodes shall be

positioned

on y=0)

4. The shell elements shall be consistently defined.

5. The parts shall be modelled in the following unit settings:

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Length in millimetres (mm)

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Time in second (s)

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Mass in tonne

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Force in Newton

6. Each part shall have one unique PID, with the following exceptions:

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Parts made of tailored blanks shall be divided into different PIDs according to

the

different thickness and material qualities of the parts.

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Extruded parts shall be divided into different PIDs according to the different

thickness and materials of extrusion.

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The thickness at different locations on a cast/moulded part

7. The preferred naming convention as below:

ST3700=1234567_A1A_3.5_B-Pillar

material

drawing no drawing rev

thickness

part name

8. All parts with identical materials properties shall refer to the same MID.

9. One model shall be used for all crash simulation

建模要求

Meshing Guideline

1. Deformation area shall be mesh with a average length 10mm. Deformation area

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shall be mesh with a minimum length of not less than 5mm. Maximum length shall not

exceed 12mm.

注：变形区域：

正面碰撞：

A

柱与

B

柱中间位置以前的所有零件及其某些零件的前部

（车门除外）

，

另外前端吸能部件，包括纵梁 前段、翼子板支撑结构等的平均单元长度为

8 mm

；

侧面碰撞：前后从

A

柱至

C

柱（包括

A

C

柱），横向左半部所有零件及其某些零

件的左半部（框内的零件及其某些零件的框内部分）；

背面碰撞：

C

立柱

（包括

C

立柱）

以后的所有零件及其某些零件的后部

（车门除外）

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2.

Noneformation area shall be mesh with a average length 15mm. All parts shall be

mesh with a minimum length of not less than 5mm. Maximum length shall not exceed

18mm.

3. No penetrations are allowed in the FE model. FE mode shall be global penetration

check .

(part thickness scale is 0.65.)

4. Element type: QUAD4 and TRIA3 (max 10% of the full model)

5. Element Check:

Aspect ratio < 3.0

Skewness < 60

Warping < 15

Crash Time Step*

＞

8.1e-07

Internal Angle

Min

Max

QUAD 40

140

TRIA 30

120

Jacobian > 0.5

* Crash time step for part B-pillar system, longitudinal, bumper system is 6.0e-7

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The part shall be completely meshed. Un-meshed areas shall not exist

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??

A “free edge” check shall be performed to verify that there are no

”cracks” in the mesh.

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??

A “shell element normal” check shall be performed to verify that the normals

are

consistently defined

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??

No duplicate grid point numbers shall exist.

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??

No duplicate element numbers shall exist

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No duplicate structural elements shall exist. A duplicate element is defined as an

element of the same type and attached to the same grid points as another

element.

3

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Avoid packing triangles together to the same grid point

6. Modelling of fillet

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If the radius of the fillet is smaller than 5mm

–

no representation of the fillet

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If the radius of the filler is =/> 5mm, a minimal of one element in fillet is

modelled.

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4

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7. Modelling of flanges

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Spotwelded flanges shall be modelled according to the figure below:

??

Try to keep the original angle of the flange. In (a), the flange has a new angle,

which is not recommended. The recommended practice is to model the

flange as in (b). This is for assembly reasons; flanges with large angular

differences may yield poor welding elements

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8. Modelling of hem flanges

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Hem flanges can be recognized by that the part is folding around itself (see figure

below)

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5

?

??

Hem flanges should be model as figure below:

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9. Modelling of holes

a) Boltholes

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For boltholes, 6 or more nodes around is required around the perimeter of the

bolthole.

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The outer perimeter of washers, distances and nuts in the bolt joint shall be

projected on the part and modelled using preferably 6 or more nodes around

the projected perimeter. In cases where the average element length is small

compared to the size of the washer, it is allowed to use more than one row of

elements between the outer and the inner washer perimeter. If the outer

perimeter of washers, distances and nuts in the bolt joint is not known, acircle with

centre in point C and a diameter of 2.0×

D

min

(D

min

= minimum

diameter of bolt hole) may be used.

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It is allowed to slightly modify the perimeter of either the bolthole or the

projected one of washers, distances and nuts in the bolt, if that improves the

element quality around the bolthole.

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If the minimum diameter of the hole is smaller than the minimum element

length (5mm), the hole shall not be modelled.

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b) Rivet holes

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Rivet holes shall not be modelled

10. Modelling of spotweld

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Spotweld are modelled as PLINK in pamcrash model. PLINK is defined by one

independent node describing the location of the spotweld as well as the parts

which is needed to be spotwelded. The location of spotweld to be defined in VIP

file

PLINK

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?

??

For arc welding, the position of the arc welding shall be represented by a node.

This node to be modelled with TIED CONTACT (TYPE 32)

–

“Node to Element”

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12. Modelling for glue

??

Modelling of glue is by SOLID (PENTA/HEXA). The solid is to be made grid to

grid to its connecting parts.

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13.

铰接

??

厚度不同的铸造铰链体用

SOLID (PENTA/HEXA)

单元模拟，其余用壳单元模拟。

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?

较销用

spring

< br>单元模拟，

spring

单元只有三个移动自由度方向的 刚度，三个转动自由

度方向的刚度为零。

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较销与铰链体之间用

rigid

单元连接。

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< /p>

动力传动系统模型建模要求（

1

天）

General

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Each part of the engine components to be modelled separately into different PIDs

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Engine package can be separated into a few different categories as per below:

a) ENGINE:

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Engine block

??

Cylinder Head

??

Cylinder Cover

??

Oil pan

b) AGGREGATES:

??

Generator

??

Water pump

??

Air conditioning compressor

??

Oil Filter

??

Pulleys, etc

c) INJECTION SYSTEM:

??

Manifold

??

Air duct

??

Air filter

??

Ignition system

d) ENGINE BAY COMPONENTS:

??

Water tanks

??

Battery

??

Brake booster, brake cylinder, brake fluid tank

??

ABS

??

Fuse box

e) GEARBOX

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Gearbox

??

Drive shaft

??

Differential

f) EXHAUST SYSTEM:

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Extractor

??

Catalytic converter

??

Pipes

??

Silencers

??

Brackets/Hooks

g) ENGINE MOUNTING

h) COOLER:

??

Radiator, Air condition cooler

??

Fan, Cage

??

Brackets etc

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Meshing Guideline

1. Engine

??

Meshing size 15~20mm

??

Only outer surface is mesh

??

To avoid hourglass issues, the ribs are to be modelled with 2 element rows.

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发动机本体在分析中作为刚体处理，但必须保证 单元质量，为此可以作适当的几何简

化处理

2. Aggregates

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Meshing size is 10mm

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These parts are mostly not deformable but there could be a possible rupture to its brackets

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Brackets have to be modelled middle surface with true thickness

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Aggregates can be model with outer shell.

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To avoid hourglass issues, the ribs are to be modelled with 2 element rows.

3. Injection system and engine bay components

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Meshing size is 10mm

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Parts to be modelled with outer surface

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