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26/11/2003. Habib Karaouni 1 Joseph Zarka 2. Intelligent Optimal Design in Fatigue and Reliability. 1) CADLM 2) LMS at Ecole Polytechique. CADLM Airways. Motivations. Errors Numerical simulations. Geometry Mechanical Prop. Loadings. Fatigue Failure?. ?. Initial State.

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26 11 2003

26/11/2003

Habib Karaouni 1Joseph Zarka 2

Intelligent Optimal Design in

Fatigue and Reliability

1) CADLM 2) LMS at Ecole Polytechique


Motivations

CADLM Airways

Motivations

Errors

Numerical simulations

Geometry

Mechanical Prop.

Loadings

Fatigue Failure?

?

Initial State

Complex

Loadings


26 11 2003

Objectives

Complex Loadings

Deterministic

1

ZAK-Det

Equivalence rule

Quasi-Local Approach

 A.I.D.S. (J. Zarka)

ZAK

Advanced Intelligent Design of Structures

3

2

ZAK-Fi

ZAK-Alea

With random conditions

Reliability

Monte Carlo


26 11 2003

Plan

  • A.I.D.S. Approach

  • Equivalence Rule

    II.1. Radial loadings

    II.2. Non-Radial loadings

    II.3. Identification of the microscopical mechanisms

  • ZAK Approach

    III.1. Principles

    III.2. Use of the A.I.D.S. Approach

    III.3. Generation of the Fatigue Design Rules

  • Perspectives

Contents


I a i d s approach

I. A.I.D.S. Approach

Advanced Intelligent Design of Structures

Principles of Automating Learning

Learning Base

RULES

+

Reliabily

LB

DB

Test Base

TB

Production Base

PD

New cases


26 11 2003

I. A.I.D.S. Approach

Advanced Intelligent Design of Structures

Primitive Description

Example

Conclusion


26 11 2003

I. A.I.D.S. Approach

Advanced Intelligent Design of Structures

With actual whole knowledge

Simplified analytical models

Simplified analysis

Complex beautiful theories

A.I.D.S.

Knowledge

Primitive Description

Intelligent Description

Rules

Cj = gj(Di)

Optimization

Experiences and

Numerical simulations


Ii equivalence rule relative to fatigue damage

II. Equivalence rule relative to fatigue damage

Hypothesis

1- Two independant scales :

a- Macroscopic Elastic-shakedown at the scale of the structure

b- Microscopic Plastic-shakedown on some microscopic mechanisms

Yield Stress  Endurance Limit

Damage = pc ouWD

Crack Initiation  Critical Damage

2- Global simplified Analysis  ZAC (Zarka/Casier)


Ii equivalence rule relative to fatigue damage1

Loading 1

Loading 2

WD1;

WD2;

or WD1 = WD2

II. Equivalence rule relative to fatigue damage

II.1. Radial Loadings

Fluctuation

max

Cf = (max + min)/2

F = (max - min)/2

min

« Measure » of the loading

LOCALCumulated plastic strain pc

LOCALDissipated Energy WD


Ii equivalence rule relative to fatigue damage2

II. Equivalence rule relative to fatigue damage

II.1. Radial Loadings

Particular Loadings

a = F

m = Cf

N


Ii equivalence rule relative to fatigue damage3

II. Equivalence rule relative to fatigue damage

II.2. Non Radial Loadings

Same Equivalence Rule

 Radial Cyclic Loading in the direction 

Loading

Plastic Strain


Ii equivalence rule relative to fatigue damage4

II. Equivalence rule relative to fatigue damage

II.3. Identification of the microscopical mechanisms

1 F. block - 1D

1 F. block - 2D

2 Friction block - 2D


Iii zak quasi local framework

5) Region/material

III. ZAK : Quasi-Local framework

III.1. Principle : Multi-scale Analysis

3) 2D Détail

1) Elastic Analysis

2) 3D Sub-Structure

A.I.D.S.

4) Window

+

Radial Cyclic Loading


Iii zak quasi local framework1

Classes

Conclusions

III. ZAK : Quasi-Local framework

III.2. Use of the A.I.D.S. Approach

  • Synthesis of the loadings  Equivalence Rule

  • Synthesis of the material (cyclic and Fatigue)

  • Synthesis of the geometries  Analysis within the

    2D region

I1, J2 ,||grad J2|| ,

DVK, Ns-n , pc

Material

Descriptors

Stress Field/Fatigue

Descriptors

- 13 Material desc.

- 72 Stress Field desc.

- 9 Fatigue desc.

- 4 size of region

- 2 kind of analysis

- 36 details

- 12 regions per detail

Given Analysis

Given size region


Iii zak quasi local framework2

MAXt

MOYt

MINt

Layer 5

M

Mmax

Layer 4

Layer 3

Mmin

Layer 2

Layer 1

III. ZAK : Quasi-Local framework

III.2. Use of the A.I.D.S. Approach

M

I1, J2 ,||grad J2|| ,

DVK, Ns-n , pc

Average of M within  (Mmoy)

Maximum of M within  (Mmax)

Minimum of M within  (Mmin) 

Region 

(MlayN) = SN / S0


Iii zak quasi local framework3

III. ZAK : Quasi-Local framework

III.3. Generation of the Fatigue Design Rules

Failure or No Failure

If Failure => Number of cycles

Software : SEA and NeuroShell

Best results : Elastic analysis + region size = .8 mm


Iv conclusions perspectives

IV. Conclusions & Perspectives

Experimental Validation of the E.R.

Increase the Data Base

  • more materials

  • more details and kind of loadings

 INDUSTRIAL QUALIFICATION OF THE FRAMEWORK

Integration of the ZAK framework in FatPro


Fatpro

  • Loadings

  • Cyclics

  • Variable Amplitudes

  • Random

  • Multiaxial

FatPro

Finite Element Analysis

  • NISA

  • CADSAP/ALGOR

  • ABAQUS

  • CASTEM

Fatigue failure models and criteria

  • Stress Life

  • Strain Life

  • Dang Van

  • Papadopoulos

  • ZAK Life

    • Decreasing of Errors linked to the mesh

    • Equivalent Rule

Demo


Thank you

Thank You!


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