Lecture 01 Ver1

8/15/2019 Lecture 01 Ver1

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CAD/CAE in Mechatronics Engineering

1Mai Duc Dai7 July 2015

. .

Faculty of Mechanical EngineeringHo Chi Minh City University of Technology and Education

Background

Bachelor’s degree in Mechanical Design Engineering

ĐHSPKT (1995-2000)


University of Liege, Belgium (2001-2003)

Ph.D in Aerospace EngineeringKonkuk University, Seoul Korea (2008-2012)


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What are the CAD, CAM and CAE ?

Need

&

Ideas

CAD (Comu!er Aided Design"1# Au!oCAD & Mec$anical Desk!o

2# %ro'

# Ca!ia

)# N*5# +olid 'dge & +olid,orks

-# Ansys7# +amce.

/# Aaus

# M+C#Nas!ran

Numerical Simulation (CA' !ools"

Geometric & Mechanism Simulation

Design

&

+imula!ion

Manu.ac!ureMarke! 3uali!y Con!rol

CAM (Comu!er Aided Manu.ac!uring"1# Mas!erCam

2# Cima!ron

# %ro' (CAM"4 Ca!ia (CAM"4 nigra$ics

CA'

1. ADAM

2. RecurDyn

3. Moldex 3D

4. Moldflow

5. NX/CAE

A mechanical engineer,


Shou know how to use at east one o

softwares in each group which previouly

listed


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CA' analysis

Thực hiện các phân tích kỹ thuật (phân tích CAE) cho các cấu kiện Cơ khí


Frequency Response Function

0

20

40

60

80

100

120

400 800 1200 1600 2000 2400 2800

FREQUENCY [Hz]

d b

[ g / N ]

X_dir

Y_dir

_dir

CA' analysis

NA+6AN8 NM'ICA9 +IM9A6I:N



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CA' analysis


CA' analysis

;orce < 0 N

;i=ed suor!



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6$e mos! common CA' analysis

Những phân tích kỹ thuật thông dụng (phân tích CAE) ?

Structural Analysis


u o y ynam cs s mu a ons

Coupled fields analysis

Fluid structure interaction

Thermo-mechanical coupling

Structural-thermoelectric analysis

Electromechanical analysis

+!ruc!ural

Analysis

+!a!ic

Analysis

Modal

Analysis

>armonic

Analysis

6ransien!

DynamicAnalysis

+ec!rum

Analysis

Buckling

Analysis

'=lici!

DynamicAnalysis

1 2 3 4 5 6 7

Plasticity

Stress stiffening

Large deflection (small strain)

Large strain (finite strain)

Hyper-elasticity

Contact surfaces

Creep.

ANSYS

LS-DYNA

only

Linear

analysis

Nonlinear

analysis

Nonlinear

analysis

Linear

analysis

Nonlinear

analysis


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+!ruc!ural Analysis8s!a!ic


+!ruc!ural Analysis8s!a!ic



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+!ruc!ural Analysis8modal


+!ruc!ural Analysis8modal


1rs! mode (10#7 >?"

2nd mode (11#- >?"


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+!ruc!ural Analysis8dro!es!


Damer ar!,eig$! Balance ar!

Bedla!e ar!

Co@er ar!




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MBD Analysis

first-stage second-stageSled Rocket

Rigid wall


booster booster

railway

Brake mechanism

Ground

Water/Sand0.8m

Sled

Rocket

MBD Analysis



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MBD Analysis


Couled .ield Analysis8;+I

Apply Piston

Hub

Retainer

Spacer

Outer Plate

nner Plate


Apply Piston


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Couled .ield Analysis8;+I

-

-20

-10

0

10

20

30

40

50

60

70

T o r q u e

( N . m

)

Dynamic Test Results

Exp. (1 cycles)

Exp. (10 cyc les)

Exp. (100 cycles)

Structure model


0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8-

time (sec)

:u!line

+!ruc!ural analysis

+!a!ic analysis (!russ4 .rame4 s$ell4 solid"

Modal analysis6ransien! analysis


Couled8;ield analysis

+!ruc!ural8!$ermoelec!ric analysis

'lec!romec$anical analysis

;inal roec!


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Numerical !ools in s!ruc!ural analysis

Structural anslysis

Analy!ic solu!ions +!reng!$ o. ma!erials

Aro=ima!e solu!ions


Numerical solu!ions

;ini!e 'lemen! Me!$od (;'M"

Boundary 'lemen! Me!$od (B'M"

Common CA' +o.!a@es



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An Introduction to

27Mai Duc Dai21 January 2015

FINITE ELEMENT METHOD

Basic +!es in !$e ;ini!e 'lemen! Me!$od

1# Discre!i?a!ion o. analysis domain2# +elec! 'lemen! 6ye

(+$ae and Aro=ima!ion"

u1

u2

u@2

@

1

2

y@1


# Deri@e 'lemen! 'ua!ions

(aria!ional and 'nergy Me!$ods"

EeFGeH < G;eH

EeF < +!i..ness or %roer!y Ma!ri=

GeH < Nodal Dislacemen! ec!or

G;eH < Nodal ;orce ec!or

)# Assemle 'lemen! 'ua!ions!o ;orm loal +ys!em

5# Incorora!e Boundary

and Ini!ial Condi!ions

EFGH < G;H

# o @e ssem e ys em o ua ons or

nknon Nodal Dislacemen!s4

+econdary nknons o. +!ress and +!rain alues


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Common 6yes o. 'lemen!s

:ne8Dimensional 'lemen!s

9ine

ods4 Beams4 6russes4 ;rames

6o8Dimensional 'lemen!s

6riangular4 3uadrila!eral

%la!es4 +$ells4 28D Con!inua


6$ree8Dimensional 'lemen!s

6e!ra$edral4 ec!angular %rism (Brick"

8D Con!inua

Discre!i?a!ion '=amles


:ne8Dimensional

;rame 'lemen!s

6o8Dimensional

6riangular 'lemen!s

6$ree8DimensionalBrick 'lemen!s


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;'M mes$

6$e numer o. elemen!s used in a model deends on a numer o. .ac!ors !$a! include

!$e .olloing

1# %$ysical geome!ry o. !$e domain


2# Desired accuracy

;'M mes$

# 'lemen! .ormula!ion

9inear .ormula!ion

elemen!s


>ig$er oder .ormula!ion

elemen!s


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;'M mes$

)# +ecial solu!ion c$arac!eris!ics


5# A@ailale comu!a!ional resources

ANSYS Classic Training

basis course


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%re8%rocessor

s!age

%re8%rocessor

s!age

Define the element types

Define the real constants

Define the material properties

Modeling

create key points, lines, surfaces, volumes

import from CAD files

Meshing

Apply Boundary conditions

geometric BCs

applied load

General steps in using Ansys classic for solving a structural analysis problems

%rocessor +!age%rocessor +!age

%os!8%rocessor+!age%os!8%rocessor+!age

Solver set-up

modal analysis

static structural analysis

nonlinear structural analysis

Run the job

Visualization of the results

displacements

stress

safety factor

…

Start-up ANSYS


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!ili!y menu Command line

,orking area

ANSYS GUI

Main menu Model con!rol!oolar

Curren! se!!ing

Utility Menu Help


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Anal sis of truss/frame structures

Truss and frame structures


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Element types

This element can be used to model trusses,

sagging cables, links, springs, etc.

This 3-D spar element is a uniaxial tension-

compression element with three degrees of

freedom at each node: translations in the nodal x,y, and z directions.

LINK180

BEAM188

s su a e or ana yz ng s en er o

moderately stubby/thick beam (or frame)

structures.

BEAM188 has six degrees of freedom at each

node, include translations in the x, y, and z

directions and rotations about the x, y, and zdirections.

This element is well-suited for linear, large

rotation, and/or large strain nonlinear applications.

Trusses


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Activity #1: Deflection of a Hinged Support (VM4)

A structure consisting of two equal steel bars, each of length l and cross-sectional

area A, with hinged ends is subjected to the action of a load F . Determine the stress,

σ , in the bars and the deflection, δ, of point 2. Neglect the weight of the bars as a

small quantity in comparison with the load F.

Material Propertiesθ θ sin,cos2 ll −== ba

Geometric Properties

Loading

Reference solution

σ = 10,000 psi, δ = - 0.12 in

Change the project title

Utility menu File→ Change Title…

Project Title


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Define element type

Main Menu Preprocessor→ Element Type→Add/Edit/Delete

Define material properties

Main Menu Preprocessor→Material Props→Material Models


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Define cross-sectional properties

Main Menu Preprocessor→ Real Constants→Add/Edit/Delete

Modeling-create nodes

Main Menu Preprocessor→Modeling→ Create→ Nodes→ In Active CS

Nodes:

x y z

1 0 0 0

2 0

3 0 0

θ cosl θ sinl−

θ cos2l

There is no unit system is defined in Ansys Classic, user have responsibility on using consistent units for

their input parameters.


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Consis!en! sys!em o. uni!s

Consis!en! sys!em o. uni!s

Mass kg

9eng!$ m

6ime s

;orce N

Densi!y kgm

+!ress %a (Nm2

"ra@i!y #/1 ms2

Mass l 8s2 in snail

SI


g < #/1ms2 < /- ins2

1.! < 12in < 0#0)/m (.oo! K .ee!"

1in < 0#025)m

9eng!$ in

6ime s

;orce l. (ounds8.orce"

or l (ound"

ens !y sna n

+!ress %si (l.in2"

ra@i!y /- ins2

m$ (miles er $our"4 1mile < 14-0 km

1l. < )#))/222 N

1ki (kiloound" < 1000 l.

UK

Units for angular functions


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Modeling-create elements

Main Menu Preprocessor→Modeling→ Create→ Elements→Auto Numbered

→ Thru Nodes

Select two nodes to define the element then click OK

Modeling- Controls entity numbering/coloring on plots

Utility Menu PlotCtrls→ Numbering …

Utility Menu Plot→ Keypoints→ Keypoints

→ Lines

→Areas

→ Volumes

→ Elements


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so$etric "ie#

!ront "ie#

Apply BCs & Load

Main Menu Preprocessor→ Load→ Define Loads→Apply→ Structural→ Displacement

→ On Nodes

Main Menu Preprocessor→ Load→ Define Loads→Apply→ Structural→ Force/Moment

→ On Nodes


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Set up solver, save & solve the problem

Main Menu Solution→ New Analysis

ANSYS Toolbar→ Save_DB

Main Menu Solution→ Solve→ Current LS

Post-processing, show deformed shape

Main Menu General Postproc→ Plot Results→ Deformed Shape


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Post-processing, Printout nodal solution per nodes

Main Menu General Postproc→ List Results→ Nodal Solution→ Displacement vector sum

Post-processing, Printout nodal forces

Main Menu General Postproc→ List Results→ Element Solution→ Structural forces

Post-processing, Printout element axial stress

Main Menu General Postproc→ Element Table→ Define Table→Add Button

Main Menu General Postproc→ Element Table→ List Elem Table→ OK Button


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Post-processing, Plot axial stress

Create one more element table, axial stress at node J


Post-processing, Plot axial stress

Plot axial stress diagram

Main Menu General Postproc→ Plot Results→ Contour Plot→ Line Elem Res


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Frame structures

Activity #2: Beam Stresses and Deflections (VN2)

A standard 30" WF beam, with a cross-sectional area A, is supported as shown below

and loaded on the overhangs by a uniformly distributed load w. Determine the

maximum bending stress σ in the middle portion of the beam and the deflection δ at

the middle of the beam.

Material Properties

Geometric Properties

in240=l

Loading

Reference solution

σ = -11400 psi, δ = 0.182 in

in0.6856t3

1.0484t2t1

in30.0968w3

in15w2w1

in120a

=

==

=

==

=


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Define element type

Main Menu Preprocessor→ Element Type→Add/Edit/Delete

Define material properties

Main Menu Preprocessor→Material Props→Material Models


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Define sectional properties

Main Menu Preprocessor→ Sections→ Beam→ Common Section

Modeling-create key points

Main Menu Preprocessor→Modeling→ Create→ Keypoints→ In Active CS

Keypoints:

1. 0 0

2. 240 0

3. -120 0

4. 360 0

10. 0 120 (orientation)


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Modeling-create lines

Main Menu Preprocessor→Modeling→ Create→ Lines→ Lines / Straight Line

Select two keypoints to define the line then click OK

Meshing – Associates element attributes with the selected, unmeshed lines.

Main Menu Preprocessor→Meshing→Mesh Attributes→ Picked Lines

1. Select lines then click OK

2. Pick Orientation Keypoint(s)→Yes→ OK

3. Specifying the keypoint 10→ OK


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Meshing – setting element size & meshing.

Main Menu Preprocessor→Meshing→ Size Cntrls→ManualSize

→ Lines→All Lines

Main Menu Preprocessor→Meshing→MeshTool

1. Click Mesh button

2. Select lines→ OK→ close MeshTool Dialog

Display elements with shapes determined from the real constants or section definition.

Utility Menu PlotCtrls→ Style→ Size and Shape…

Utility Menu Plot→ Elements


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Apply BCs

Main Menu Preprocessor→ Load→ Define Loads→Apply→ Structural→ Displacement

→ On Lines (or On Keypoints)

BCs on Lines:

1, 2, 3 Uz=Roty=Rotx=0

BCs on Keypoints:

1 Ux=Uy=0

2 Uy=0

Apply load

Main Menu Preprocessor→ Load→ Define Loads→Apply→ Structural→ Pressure

→ On Beams


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Set up solver, save & solve the problem

Main Menu Solution→ New Analysis

ANSYS Toolbar→ Save_DB

Main Menu Solution→ Solve→ Current LS

Post-processing, show deformed shape

Main Menu General Postproc→ Plot Results→ Deformed Shape


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Post-processing, Printout nodal solution per nodes

Main Menu General Postproc→ List Results→ Nodal Solution→ Displacement vector sum

the deflection δ at the

middle of the beam

Post-processing, plot bending stress diagram


Comp: 2, 15 for bending moment


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Post-processing, Plot bending stress

Plot bending stress diagram

Main Menu General Postproc→ Plot Results→ Contour Plot→ Line Elem Res

2-Dimensional Elastic Problems

Documents

Lecture 01 Ver1