JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 51

AERONAUTICS
structures

Optimisation of sandwich composite
structures for space applications
CédriC julien, Ph.D., Research Scientist,
FrançoiS-Xavier iriSarri, Ph.D.,
Research Scientist, dimitri bettebghor,
Ph.D., Research Scientist,
Onera
Florian lavelle, Materials and
Structures Engineer, kevin mathiS,
Materials and Structures Engineer,
CNES

With the increasing use of advanced composite materials in launcher structures comes the issue of the optimum design of composite structures. Over
the past years, the space industry has been experiencing an important change.
What was a steady-state dominated by a handful of major companies and
institutions now has to face a new impulsion coming from disruptive companies
all over the world. The space economy is growing; private players, applications
and projects are multiplying.

T

Still looking for
the best design practice
However, this replacement dynamics
slowed down in the past decades as composite solutions were not always competitive in terms of costs or even performance
compared to metallic ones. Many reasons
can explain this: higher performance of
aluminium alloy technology (material
characteristics and effective assembly
processes); high experimental support for

A novel tool covering
the whole design process
The past decades have seen the development
of automation, and growth in materials and

manufacturing process solutions, which
have opened the door to higher production
rates, robustness and quality, but also the
ability to manufacture more diversified,
complex and functionalized designs. At the
same time, new methodologies are emerging that make behaviour predictions more
precise, resulting in lower experimental
efforts and more complex designs, and
enable design optimisation.
But a research effort is now needed to devise
new design tools for launcher structures.
To face the increasingly complex design
of composite structures, and owing to the
relative absence of integrated composite
design tools, CNES and Onera decided to
join their efforts in developing a novel tool
for the optimum design of composite structures, which aims to cover the whole design
process of a structure, from the search for
the structural concept to the prediction of
damage and failure in the most critical areas.
This joint work is performed within the
framework of the R&T Launchers CNES/
ONERA. This tool would take into account
many specificities of these materials - especially their anisotropic non-linear behaviour
and manufacturing constraints - and be
applicable to a wide range of structures,
from shells to lattice and wound structures,
and of processes (hand lay-up, fibre placement, thermo-moulding, etc.). This article
presents the outcome of the first step of this

Feature Aeronautics

he key to success in this competition
seems to be cost reduction together
with quick adaptability to market
evolutions (fast developments, performance improvement and solutions for new
applications). Composite materials are
clearly a key technology in this struggle.
Due to their better density/performance
ratio, composite materials have replaced
metal step by step in launchers as a key
driver to maximize payload. With compression-dominated structures prone to buckling, CFRP and aluminium honeycomb
sandwich materials have become a natural
solution for fairings, payload adaptors,
inter-stage skirts, etc. Moreover, wound
composites offer an interesting alternative
to steel and aluminium for high-pressure
tanks.

the development of composite structures,
thus increasing costs and limiting material
and concept choices; limitations in manufacturing processes (difficulties to control
quality and reproducibility, difficulties to
manufacture complex shapes such as double curvatures, etc.); but also limitations in
design methods.
Indeed, the aerospace and aeronautics
industries are still looking for the best
practice to design composite structures.
The most advanced methods currently used
are either very expensive computationally,
or require massive and costly experimental
validations, thus limiting their use to the
most critical parts only. For more common
parts, design is conducted with a traditional
approach relying on conservative guidelines
that hamper the development of design
tools that would really take advantage of the
design freedom offered by composite structures. This results in oversized structures as a
means to compensate for their lack of sound
physical basis, so that the specific features
and advantages of composite materials are
not fully exploited, and composite solutions
are often undervalued compared to metallic
solutions, which are much more readily
available and easy to model.

/ jec composites magazine

51

No112 April - May 2017



Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017

Cover
Edito
Opinion: Civilian robotic
Contents
NEWS
In brief
Yachting
Strategy
Fabric
Agenda
BUSINESS
Additive manufacturing
Carbon
MANUFACTURING
Press
Repair
CNC
Natural fibres
Feature Aeronautics - Will the horizon stay clear?
Simulation
Software
NDT
Tooling
Self healing
Primary structure
Natural fibre
Recycling
Environment
Structures
SOLUTIONS
Sustainability
Sailplane
Lift
Construction
In the world
TECHNOLOGY
Nanomaterials
Thermoplastics
CFRP
Index
Advertisers
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 68
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Cover
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 2
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Edito
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Opinion: Civilian robotic
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 5
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Contents
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 7
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - In brief
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 9
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Yachting
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 11
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Strategy
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 13
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Fabric
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 15
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Agenda
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 17
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Ad IPC
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Ad JEC
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Additive manufacturing
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 19
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Carbon
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 21
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 22
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Press
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 24
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Repair
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - CNC
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 27
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Natural fibres
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 29
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 30
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Simulation
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 32
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Software
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 34
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - NDT
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 36
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Tooling
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 38
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 39
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 40
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Self healing
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 42
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Primary structure
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 44
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Natural fibre
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 46
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 47
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Recycling
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 49
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Environment
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Structures
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 52
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 53
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Sustainability
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Sailplane
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Lift
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Construction
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - In the world
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Nanomaterials
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 60
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 61
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Thermoplastics
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 63
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - CFRP
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 65
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - Advertisers
JEC COMPOSITES MAGAZINE - Issue #112 - April/May 2017 - 67
https://www.nxtbook.fr/newpress/jeccomposites/jcm_2020_Q1_Innovation_Report
https://www.nxtbook.fr/newpress/jeccomposites/jcm2005_Special_Issue3
https://www.nxtbook.fr/newpress/jeccomposites/jcm2005_134
https://www.nxtbook.fr/newpress/jeccomposites/jcm2003_133
https://www.nxtbook.fr/newpress/jeccomposites/jcm2001_132
https://www.nxtbook.fr/newpress/jeccomposites/jcm1911_Special_Issue2
https://www.nxtbook.fr/newpress/jeccomposites/jcm1911_131
https://www.nxtbook.fr/newpress/jeccomposites/jcm1909_130
https://www.nxtbook.fr/newpress/jeccomposites/jcm1907_129
https://www.nxtbook.fr/newpress/jeccomposites/jcm1905_128
https://www.nxtbook.fr/newpress/jeccomposites/jcm1903_Special_Issue1
https://www.nxtbook.fr/newpress/jeccomposites/jcm1903_127
https://www.nxtbook.fr/newpress/jeccomposites/jcm1901_126
https://www.nxtbook.fr/newpress/jeccomposites/jcm1811_125
https://www.nxtbook.fr/newpress/jeccomposites/jcm1810_124
https://www.nxtbook.fr/newpress/jeccomposites/jcm1808_123
https://www.nxtbook.fr/newpress/jeccomposites/jcm1807_122
https://www.nxtbook.fr/newpress/jeccomposites/jcm1805_121
https://www.nxtbook.fr/newpress/jeccomposites/jcm1804_120
https://www.nxtbook.fr/newpress/jeccomposites/jcm1803_119
https://www.nxtbook.fr/newpress/jeccomposites/jcm1802_119-Supplement_Innovation_Report
https://www.nxtbook.fr/newpress/jeccomposites/jcm1801_118
https://www.nxtbook.fr/newpress/jeccomposites/jcm1711_117
https://www.nxtbook.fr/newpress/jeccomposites/jcm1710_116
https://www.nxtbook.fr/newpress/jeccomposites/jcm1708_115
https://www.nxtbook.fr/newpress/jeccomposites/jcm1707_114
https://www.nxtbook.fr/newpress/jeccomposites/jcm1706_113
https://www.nxtbook.fr/newpress/jeccomposites/jcm1704_112
https://www.nxtbook.fr/newpress/jeccomposites/jcm1703_111
https://www.nxtbook.fr/newpress/jeccomposites/jcm1701_110
https://www.nxtbook.fr/newpress/jeccomposites/jcm1611_109
https://www.nxtbook.fr/newpress/jeccomposites/jcm1610_108
https://www.nxtbook.fr/newpress/jeccomposites/jcm1608_107
https://www.nxtbook.fr/newpress/jeccomposites/jcm1607_106
https://www.nxtbook.fr/newpress/jeccomposites/jcm1605_105
https://www.nxtbook.fr/newpress/jeccomposites/jcm1604_104
https://www.nxtbook.fr/newpress/jeccomposites/jcm1603_103
https://www.nxtbook.fr/newpress/jeccomposites/jcm1601_102
https://www.nxtbook.fr/newpress/jeccomposites/jcm1511_101
https://www.nxtbook.fr/newpress/jeccomposites/jcm1510_100
https://www.nxtbook.fr/newpress/jeccomposites/jcm1509_99
https://www.nxtbook.fr/newpress/jeccomposites/jcm1507_98
https://www.nxtbook.fr/newpress/jeccomposites/jcm1505_97
https://www.nxtbook.fr/newpress/jeccomposites/jcm1504_96
https://www.nxtbook.com/newpress/jeccomposites/jcm1503_95
https://www.nxtbook.com/newpress/jeccomposites/jcm1501_94
https://www.nxtbook.com/newpress/jeccomposites/jcm1412_93
https://www.nxtbook.com/newpress/jeccomposites/jcm1410_92
https://www.nxtbook.com/newpress/jeccomposites/jcm1409_91
https://www.nxtbook.com/newpress/jeccomposites/jcm1406_90
https://www.nxtbook.com/newpress/jeccomposites/jcm1405_89
https://www.nxtbook.com/newpress/jeccomposites/jcm1404_88
https://www.nxtbook.com/newpress/jeccomposites/jcm1403_87
https://www.nxtbook.com/newpress/jeccomposites/jcm1401_86
https://www.nxtbook.com/newpress/jeccomposites/jcm1311_85
https://www.nxtbook.com/newpress/jeccomposites/jcm1310_84
https://www.nxtbook.com/newpress/jeccomposites/jcm1308_83
https://www.nxtbook.com/newpress/jeccomposites/jcm1307_82
https://www.nxtbook.com/newpress/jeccomposites/jcm1305_81
https://www.nxtbook.com/newpress/jeccomposites/jcm1304_80
https://www.nxtbook.com/newpress/jeccomposites/jcm1303_79
https://www.nxtbook.com/newpress/jeccomposites/jcm1301_78
https://www.nxtbook.com/newpress/jeccomposites/jcm1212_77
https://www.nxtbook.com/newpress/jeccomposites/jcm1210_76
https://www.nxtbook.com/newpress/jeccomposites/jcm1208_75
https://www.nxtbook.com/newpress/jeccomposites/jcm1207_74
https://www.nxtbook.com/newpress/jeccomposites/jcm1206_73
https://www.nxtbook.com/newpress/jeccomposites/jcm1204_72
https://www.nxtbook.com/newpress/jeccomposites/jcm1203_71
https://www.nxtbook.com/newpress/jeccomposites/jcm1201_70
https://www.nxtbook.com/newpress/jeccomposites/jcm1111_69
https://www.nxtbook.com/newpress/jeccomposites/jcm1110_68
https://www.nxtbook.com/newpress/jeccomposites/jcm1108_67
https://www.nxtbook.com/newpress/jeccomposites/jcm1107_66
https://www.nxtbook.com/newpress/jeccomposites/jcm1105_65
https://www.nxtbook.com/newpress/jeccomposites/jcm1104_64
https://www.nxtbook.com/newpress/jeccomposites/jcm1103_63
https://www.nxtbook.com/newpress/jeccomposites/jcm1101_62
https://www.nxtbook.com/newpress/jeccomposites/jcm1011_61
https://www.nxtbook.com/newpress/jeccomposites/jcm1010_60
https://www.nxtbook.com/newpress/jeccomposites/jcm1009_59
https://www.nxtbook.com/newpress/jeccomposites/jcm1006_58
https://www.nxtbook.com/newpress/jeccomposites/jcm1005_57
https://www.nxtbook.com/newpress/jeccomposites/jcm1004_56
https://www.nxtbook.com/newpress/jeccomposites/jcm1003_55
https://www.nxtbook.com/newpress/jeccomposites/jcm1001_54
https://www.nxtbook.com/newpress/jeccomposites/jcm0911_53
https://www.nxtbook.com/newpress/jeccomposites/jcm0910_52
https://www.nxtbook.com/newpress/jeccomposites/jcm0909_51
https://www.nxtbook.com/newpress/jeccomposites/jcm0907-08_50
https://www.nxtbook.com/newpress/jeccomposites/jcm0906_49
https://www.nxtbook.com/newpress/jeccomposites/jcm0904_48
https://www.nxtbook.com/newpress/jeccomposites/jcm0903_47
https://www.nxtbook.com/newpress/jeccomposites/jcm0901_46
https://www.nxtbook.com/newpress/jeccomposites/jcm0811_45
https://www.nxtbook.com/newpress/jeccomposites/jcm0810_44
https://www.nxtbook.com/newpress/jeccomposites/jcm0809_43
https://www.nxtbook.com/newpress/jeccomposites/jcm0807_42
https://www.nxtbook.com/newpress/jeccomposites/jcm0806_41
https://www.nxtbook.com/newpress/jeccomposites/jcm0805_40
https://www.nxtbook.com/newpress/jeccomposites/jcm0803_39
https://www.nxtbook.com/newpress/jeccomposites/jcm0801_38
https://www.nxtbook.com/newpress/jeccomposites/jcm0712_37
https://www.nxtbook.com/newpress/jeccomposites/jcm0710_36
https://www.nxtbook.com/newpress/jeccomposites/jcm0709_35
https://www.nxtbook.com/newpress/jeccomposites/jcm0707_34
https://www.nxtbook.com/newpress/jeccomposites/jcm0706_33
https://www.nxtbookmedia.com