2014, montréal advanced composite simulation - · pdf fileadvanced composite simulation...

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Advanced Composite Simulation

September 25th 2014, Montréal

Benoît Magneville – [email protected] LMS Engineering

Project Manager, Composite Expert

2014-09-25

Restricted © Siemens AG 2013 All rights reserved.

Siemens PLM Software


Engineering challenges

OPTIMIZATION to minimize weight

Manufacturing Many potential DAMAGE

mechanisms

Temperature affects behavior

Manage acoustic performance with reduced weight

Unknown vibrational behavior

Stiffness reduction

and failure due to

FATIGUE

Resistance to Lightning (in development)

2014-09-25




LMS Engineering, composite development partner

2014-09-25



Agenda

• Application of material identification methodology for advanced

damage analysis of Composites

• Composites structure optimization under Sizing and Design

constraints

• Fatigue of Continuous Fiber Composites for Variable amplitude loads:

a new methodology

2014-09-25



Which composites are considered here?

• Load carrying structural parts

Continuous fibers,

structured laminated

composite

Unidirectional ply

(UD)

Multi-axial plies NCF

(Non Crimp Fabric)

Woven fabric

• High performance structured composites (low weight, high stiffness and

strength)

Aerospace application Automotive application


Application of material identification

methodology for advanced damage

analysis of Composites

Benoît Magneville – [email protected]

2014-09-25



Damage in Composites:

LMS Samtech solutions based on Continuum

Damage Mechanics (CDM)

Intra-laminar failure Inter-laminar failure

• Damage evolution law by Ladeveze and Allix • Damage modeling of the elementary ply for laminated composites, Composites Science and Technology 43, 1992

Non-local

Model with

coupling

Native damage

models in LMS

Samcef

2014-09-25






• The approach is based on the Continuum Damage Mechanics

• Intra-laminar failure of the unidirectional plies

ALONG THE FIBERS IN THE MATRIX

2014-09-25



• Inter-laminar failure: Delamination




2014-09-25






Availability at all stages of end-to-end testing process

• From composite materials identification at coupon level

• To composite structures sizing at components & full scale level

2014-09-25



Damage material properties identification with

coupon analyses

Challenges:

Identify the non linear material properties at the coupon level

Have accurate material models for the progressive damage

modeling, easy to use

Solution:

Native damage models for inter and intra-laminar failures

(Cachan models)

LMS Engineering knowledge for parameter identification

Transfer of technology

Benefits:

Virtual material testing, with the non-linearities

Determine allowables in a damage tolerant approach

Input for detailed sizing

02322

223

01312

213

01212

212

332202

023

331101

013

221101

012

0322

233

03

233

02

222

0222

222

0111

211

)1(2)1(2)1(2

)1(222)1(2)1(2

GdGdGd

EEE

EdEEEdEded

Coupon level

2014-09-25



Damage material properties identification with

coupon analyses

• Tests needed

• Number of tests

• Associated standards

• Test output requested

• Parameter identification procedure: a comprehensive test protocol exists

• Technology-transfer projects are proposed for parameters identification

2014-09-25



Challenges • Weight saving requirements instigate adoption of light weight laminated

composite materials in body design

• Use of new materials necessitates the development of new design

performance evaluation methodology

• The reliability & strength behaviour of composites under complex loading is

non-linear

• Need for development of predictive models and related material

characterization procedures for progressive damage analysis and body

performance evaluation

Solution • LMS Samcef Mecano non-linear finite element solver

• LMS Engineering Services for composite damage model identification

Results • Sophisticated material models comprehensively implemented for:

• Progressive ply damage (strength, non-linearities, plasticity, coupling

effects in the matrix)

• Delamination (possibly coupled to damage in the plies)

• Development of the parameter identification procedure, based on a limited

amount of physical tests on coupons

• Predictive damage models at the coupon level and at composite subsystem

design concept level

Honda R&D Co., Ltd.

Innovative Methodology for Progressive Damage

Analysis in Composite Design

Composite Delamination

Progressive ply damage

2014-09-25



Exploitation of the methodology

• Validation of damage models at coupon level Starting from identified material parameters, the damage model is used to predict

the mechanical behavior at the coupon level for evaluation of the behaviour for

other stacking sequences and hence replacing physical tests.

• Application of damage models for predictive

delamination behavior at component level The damage models are supporting the prediction of the progressive damage

and delamination inside the plies and at their interface at component level

Honda R&D Co., Ltd.



Progressive ply damage

Progressive delamination

Source : “Strength Calculation of Composite Material considering multiple progress of failure by

Ladaveze model”, Y.Urushiyama, T. Naito, JSAE Spring Conference, 2014 52 05

2014-09-25



• Application of damage tolerant approach for composite design • Barely visible impact damage

• Damage induced by a low energy impact

• Delamination appears at the interfaces between the plies

• Agreement between simulation and C-scan test results

Honda R&D Co., Ltd.



The stains represent the level of delamination

2014-09-25



LATECOERE

Delamination of a pre-cracked stiffener

Existing crack

Existing cracks Cap (4 plies)

[45/90/0/-45]

Skin (9 plies)

[0/90/45/0/-45/90/0/45/-45]

Imposed displacement

Flange- left part (4 plies)

[-45/90/0/45]

Clamp

Challenges:

Investigate the damage propagation at the interfaces of

plies in a composite structure

Multi-delaminated composite material

Many contact conditions between initial defects

Fast solution procedure

Solution:

LMS Samcef with a specific approach for modeling

delamination

LMS Samcef solution with efficient solvers

Benefits:

Better knowledge of the composite structure, with a

damage tolerant approach

Decrease the safety margins for the composite design

Component level

2014-09-25



DAHER

Test Prediction on stiffened panel

Challenge:

• Evaluate the quality of the test facilities

Solutions:

• LMS Samcef Field for the pre/ post processing

• LMS Samcef non linear solver

• Interlaminar + Intralaminar damage

Benefits:

• Very accurate results

• New design for the test facilities

proposed

Component level

2014-09-25



Benefits:

Better knowledge of the non linear structural behavior

Virtual prototype of stiffened panels

Test

Simulation

Challenges:

Non linear analysis of thin-walled damaged stiffened

composite panels: buckling, post-buckling and collapse

Accurate results and fast solution procedure

Solution:

SAMCEF non linear solver

Use of advance progressive damage laws at the detailed

sizing level

DLR

Composite panel with de-bonding stringer

Sub-system level

2014-09-25



AIRBUS GROUP INNOVATIONS

AIRBUS HELICOPTERS

Damage analysis on composite Helicopter Blade

Challenges:

Investigate the composite damage in a pre-cracked helicopter

blade.

Check the simulation capabilities to predict the damage evolution

Solution:

SAMCEF modeling tools and non linear solver

Use of advance progressive damage laws at the detailed sizing

level

Damage mesomodel

Elastic behaviour

Benefits:

Prediction of final load and prediction of the damage evolution

was performed with success

Better knowledge of the non linear structural behavior

DIC results

Sub-system level

2014-09-25



CEA

Engineering Service: Burst Test Simulations Using

Advanced composite modeling

Challenges:

• Hydrogen storage is a key issue for the high

scale deployment of fuel cell applications

• Necessary to reach a significant cost

reduction of these storage systems

• Optimization of the composite structure can be

reached thanks to numerical simulation

Solution:

• Parametric Finite Element model

• Use of complex damage modeling for burst

mode type identification

• Use LMS Samcef Mecano solver

Benefit :

• Good correlations with reference tests

• Optimization results – Mass decreased by >30%

• Development of adapted method and tools

Sub-system level


Composites structure optimization under

Sizing and Design constraints


2014-09-25



Optimization

Brief overview of LMS Samtech Samcef capabilities

Optimization with

geometric non linearites

(buckling, post-buckling,

collapse)

Local optimization

Optimization wrt ply

thickness & fibers

orientation

Local optimization

Stacking Sequence

Optimization (design

rules + inter-regional ply

continuity)

Local/global optimization

Very Large scale

optimization problems

Global Optimization

• Local optimization (thickness, fiber orientation)

• Stacking sequence optimization with manufacturing constraint

• Vary large scale optimization (preliminary design of full structures)

2014-09-25



Optimization methods

• Genetic Algorithms

• Response Surface Methods • based on an imported data base

• based on a DOE created with our tool (Taguchi tables, D-optimal, …)

• Surrogate Based Optimization • based on a response surface with NN

• based on GA

• enriched data base at each iteration

• Specific integer programming

• For stacking sequence optimization of composite structures

• Gradient based methods

• MP: SQP, Multiplier, CG

• SCP: Conlin, MMA, GCM, …LARGE SCALE OPTIMIZATON

2014-09-25



AIRBUS

Geometric NL behavior of stiffened panels, up to final

collapse

d

Buckling Post-buckling Collapse

Collapse

Unstable path

Decrease the weight and

put those points to

prescribed values

Stiffened composite panels

Thin walled structures

= load factor

d = transverse displacement

Buckling

0 jj ΦSK

Linear analysis

Post-buckling

0)()(),( int qFFqF ext

Non linear analysis

d

• 1st step: Local optimization

• Minimize the weight while keeping buckling and collapse load above

prescribed values

2014-09-25



AIRBUS


collapse

Panel: 3 d.v. t0°, t90°, t45°

Hat: 3 d.v. t0°, t90°, t45°

Total: 36 d.v.

? 0°

? 90°

? 45° ? -45°

? 0°

? 90°

? 45°

? -45°

• 1st step: Local optimization

• Preliminary study: Total thickness of each UD orientation is a continuous variable

2014-09-25



AIRBUS


collapse

• Initial Assumption: Buckling optimization: Linear stability analysis in the optimization loop

0

0.5

1

1.5

2

2.5

3

0 2 4 6 8 10 12 14

Iterations

Desig

n functions

1

Relative weight

Weight min

1boundRFbuckling

Weight = 1.

1 = 2.7

Weight = 0.69

1 = 1.2

collapse = 1.05 < 1.2

Non linear analysis

must be included into

the optimization loop

collapse

Non conservative solution !

Due to geometric non-linearities

2014-09-25



AIRBUS


collapse

Weight min

1boundRFbuckling

2boundRFcollapse

0

0.5

1

1.5

2

2.5

3

0 2 4 6 8 10

Iterations

Desig

n functions

1

collapse

Relative weight 0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 10 20 30

Transversal displacement (mm)

Lo

ad

fa

cto

r

Weight = 0.61

1 = 0.8

collapse = 1.2

0

0.5

1

1.5

2

2.5

0 10 20 30 40

Transversal displacement (mm)

Lo

ad

fa

cto

r

Weight = 1.

collapse = 2.1

1 = 2.7

We can tune the shape of the

load-displacement curve

• Correct Assumption: Buckling, post-buckling and collapse optimization (NL analyses)

2014-09-25



AIRBUS


collapse

Weight = 1.

collapse = 2.1

1 = 2.7

Bad thicknesses and

fibers proportions

Global buckling mode

Initial design

Heavy structure

Weight = 0.61

1 = 0.8

collapse = 1.2

Good thicknesses and

fibers proportions

Local buckling modes,

before the collapse

Optimal design

Safer and lighter

structure

• 1st step: Local optimization: Conclusion

2014-09-25



Local-global optimization

Stacking sequence optimization over a structure

• 2nd step: Local/Global optimization (Stacking sequences optimization)

In each zone, optimal stacking sequence

(plies at 0°, 90°, 45°, -45°)

Design rules

Across the zones, manufacturing constraint (ply continuity)

OK

KO

2014-09-25





Backtracking algorithm optimal stacking sequence table generator

Data from step 1 Nb of plies Number of plies

For a given number of

plies, optimal stacking

sequence

Ply drops between the

zones: ply continuity

OK

KO

2014-09-25





Local and Local-Global optimization Conclusion

0°

90°

45° -45°

0°

90°

45°

-45°

Step 1: optimization of ply

thickness for 0, 90, 45 and -45

Step 2: backtracking (plies shuffling)

Min weight

Stability constranits

Possibly with NL

analysis

- Design rules OK

- Manufacturing constraint OK

- Buckling / Collapse OK

2014-09-25



Wings

1000 DV’s

250000 Constraints

Central Wing Box

250 DV’s

160000 Constraints

Vertical Tail Plane

100 DV’s

100000 Constraints

Horizontal Tail Plane

100 DV’s

100000 Constraints

Optimal preliminary sizing of the A350

Large-scale optimization

Centre Wing

Box

Horizontal Tail

Planes

Vertical Tail

Plane

Outer Wing

Box

2014-09-25





• Panel design variables

Design Variables:

t – Skin Thickness

p0 – Percentage 0-degree

p90 – Percentage 90-degree

Design Variables:

ba - Stringer foot width

h - Stringer height

ta – Stringer angle thickness

tb – Stringer core thickness

• Stiffener design variables

NXYg

NXYd

NXd

NYd

NXg

NYg

PX

• Super-stringers

2014-09-25





• Sizing criteria taken into account in the optimization

• Mass

• Buckling

• Damage tolerance

• Reparability

• Design rules

• Micro-strains

• …


Fatigue of Composites for Variable

amplitude loads: a new methodology


2014-09-25



Fatigue of continuous fiber composites

Advantage and challenge

• Composites typically show good fatigue

behavior (many load cycles till failure)

• But: Fatigue onset is very early

Macroscopic stiffness change

• Therefore: Designing for fatigue vs. no

damage means:

• Benefit from good fatigue behavior

• Extra weight reduction

Unidirection

al ply

Multi-axial

plies NCF Woven

fabric

Light weight advantage

2014-09-25




Progressive Stiffness Degradation Modeling

Typical stiffness degradation curve

3 phases

Continuum Damage Mechanics framework

with damage growth rate equation dD/dN

𝜕𝑑𝐼

𝜕𝑁= 𝑐1 ∙ Σ𝐼 ∙ 𝑒

−𝑐2𝑑𝐼

Σ𝐼 + 𝑐3 ∙ 𝑑𝐼 ∙ Σ𝐼2 1 + 𝑒 𝑐5 Σ𝐼−𝑐4

(W.V.Paepegem, 2001)

• Intra-laminar failure for the UD (same approach as Cachan static damage model)

e

E0

E0(1-d)

0

2322

2

23

0

1312

2

13

0

1212

2

12

33220

2

0

2333110

1

0

1322110

1

0

12

0

322

2

33

0

3

2

33

0

2

2

22

0

222

2

22

0

111

2

11

)1(2)1(2)1(2

)1(222)1(2)1(2

GdGdGd

EEE

EdEEEdEded

2014-09-25




Constant amplitude loading (Past experience)

Work with an university partner, expert in fatigue of composites:

Ghent University (Belgium) – Prof. Wim Van Paepegem

1. Static cycle

2. Fatigue law ...

N

d

3. Increase of the damage variable (Dd), for the

Gauss point on all elements

4. Determine DN (= NJUMP « global »)

5. Update the damage level Ddi (loop on the elements)

2014-09-25




Variable amplitude loading

Improved Cycle Jump algorithm

• Tests and calculation on ply level

• Possible lay-up optimization

• No new tests for variable amplitude

• Stiffness degradation and stress redistribution

Proven hysteresis operator approach

• Only efficient approach to cover continuous loss

in stiffness and fatigue resistance

Allows simulation of full structures Brokate, M; Dressler, K; Krejci, P: Rainflow counting and energy

dissipation in elastoplasticity, Eur. J. Mech. A/Solids 15, . 705-737,

1996

Nagode, M., Hack, M. & Fajida, M. “High cycle thermo-mechanical

fatigue: Damage operator approach”, Fatigue Fract Engng Mater

Struct 32(6), 505-514, Wiley & Son, 2009

Nagode, M., Hack, M. & Fajida, M., “Low cycle thermo-mechanical

fatigue: Damage operator approach”, Fatigue Fract Engng Mater

Struct 33(3), 149-160, Wiley & Son, 2010

Nagode, M. & Hack, M.: “The damage operator approach, creep

fatigue and visco-plastic modeling in thermo-mechanical fatigue”,

SAE International Journal of Materials & Manufacturing, 4(1), 632-

637. doi:10.4271/2011-01-0485, 2011.

Van Paepegem, W ; Degrieck, J; “Fatigue Degradation modelling

of plain woven glass/epoxy composites”, Composites: Part A

32:1433-1441, 2001

Van Paepegem, W.; “Development and finite element

implementation of a damage model for fatigue of fiber reinforced

polymers” Ph. D. thesis, Department of Material Science and

Engineering, Ghent university, 2002.

Xu, J., Lomov, S.V., Verpoest, I. Daggumati, I., Paepegem, W.

Van and Degrieck. J., “Meso-scale modeling of static and fatigue

damage in woven composite materials with finite element method.”

presented in 17th International Conference on Composite Materials

(ICCM-17). 2009. Edinburgh: IOM Communications Ltd.

Xu, J; “Meso Finite Element Fatigue Modelling of Textile

Composites” Ph. D. thesis, Dept MTM, Katholieke Universiteit

Leuven, Belgium, 2011

2014-09-25




Conclusion

Fatigue behaviour of Metals

& Composites

Exploit full advantage of

the gradual stiffness

degradation characteristics

of composite in design

Include dynamic loading in the

design process

Complex cyclic loading

scenarios

FE Composite

Modelling

Technology for

composite durability

evaluation based on

progressive stiffness

degradation model

Fiber orientation & Ply

stacking

Efficiency Accuracy

Fatigue material

properties at ply level

2014-09-25




Conclusion

Engagement model

• Engineering Services & Transfer of Technology

Test set up

Material

Characterization

FE Composite

Modelling

Assistance for test design and set-up

• Workshops

• Tests specifications

• Characterize Material

• Tools based on standard software

• Lead through process

• User defined damage models

Material characterization

Fatigue calculation


Thank you


20XX-XX-XX Siemens PLM Software


2014, montréal advanced composite simulation - · pdf fileadvanced composite simulation...

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