Cooperation between research and
industry – a German perspective
Arno van Wingerde
[email protected]
1
© Fraunhofer
A typical conversation between research
and industry
Scientist
Industry
5th
A new
dimensional , highly non-linear material theory
according to [who.ever & some.one.else] using the modified
algorithm by now also incorporating time-dependent effects such
as……..
Using the rather elegant equation, developed by DTU:
It follows that, as can be
clearly confirmed by FE
analysis, we reduced the error
by a full 0.04%!
Impressive or what?
2
© Fraunhofer
Nice… I guess,
Meanwhile I have a real problem:
Successful cooperation
Most brilliant theories
… are not applied because of complexity, poor implementation and documentation
Can they be verified?
Does the certification body agree?
Is there a standard?
Offer a solution to today’s problem
Industry’s idea of “long-term” is about “one year ahead”
Approval of research projects takes often 2 years (in Germany…)
Project itself 3-5 years.
Meanwhile focus of the industry has shifted completely
Start of contacts: use of research facilities for experimental testing
Especially if one-of-a-kind and with direct use, for instance accreditation
Based on experience gained: more value for industry
Contacts developed: further cooperation
3
© Fraunhofer
Fraunhofer´s business model:
industry focus as success factor
67 Fraunhofer institutes in Germany, Europe’s largest research organization
More than 23.000 employees, mainly with natural or engineering science education
€ 2.0 billion annual research budget
1/3
public basic
funding
1/3
third-party
grants
1/3 yields from
industry orders
4
© Fraunhofer
Example: Rotor Blade Requirements
Material Costs
Labour Costs
Interest Charges
Depreciation
High
High
Strength
strength
Other Costs
Low Structural
Costs
Growing
Dimensions
High Reliability
High Numbers
Low
Weight
Low
weight
Aviation
Automotive
6
Wind
© Fraunhofer
Costs of Bad Quality?
Example: rotor blade certification in 4 easy steps
(well… from a test institute’s point of view)
1. Establish material properties
Static :UTS, UCS, ….
R-1:
CLD:
2. Design a blade
3. Do a blade test
4. Get your certificate!
7
© Fraunhofer
Purpose of blade test
(IEC-61400-23)
Demonstrate to reasonable level of certainty
That specified limit states are not reached
blades possess strength and service life provided for in design
when manufactured according to certain set of specifications
Blade must be shown to withstand both ultimate loads and fatigue loads
Full-scale tests are normally tests on limited
number of samples
Only one or two blades of given design are tested
no statistical distribution of production blade strength can be obtained
Tests give information valid for blade type
No replacement for rigorous design process
No replacement for quality system for series blade production
8
© Fraunhofer
Full scale blade test
70m Rotor blade test stand
Static test 56m blade: Suction side under Pressure
Determination of the test loads
Medge
Without further analysis:
IEC: 75% blade width each side
GL: 80% Blade width, each side
Mload case
Mdu
Mtarget-u
Mloadframes
10
© Fraunhofer
5 years after opening we tested the world’s largest blades
From this basis: develop further tests.
Elements & Details
(bond line, ply drops in spar
cap, …)
Coupons
(consituents,
laminae, laminates,
core materials, …)
Source: IEC 61400-5 (draft version)
11
© Fraunhofer
Data Base
Sub-Components
(spars, shells, root sections,
…)
Structural Features
Nobody home….
Generic Specimen
Non-Generic Specimen
Increased Complexity
Increased number of tests
Full Scale Test
Blade components
Root connections
Transition part
Buckling panels
Trailing edge segments
Leading edge segments
Chord, Chord-web
12
© Fraunhofer
Plydrops
Bondlines
Spar cap to web bond line component testing
Beam cross section
10 mm
30
25
20
15
5.0
2.5
0.0
10
-2.5
5
0
-5.0
50
240
430
630 830 1030 1230
x [mm]
Axial stress
Shear stress
13
Shear stress [N/mm²]
26 mm
Critical Area
Axial stress [N/mm²]
97,5 mm
10 mm
32 mm
80 mm
s1 ≈ 13 MPa
s13 ≈ 2 MPa
© Fraunhofer
Sub-Component test: Bond lines
Transversal cracks (mode I), 10% Nf
Cracks extend into laminate
Longitudinal crack (mode II), 60-70% Nf
“kissing” cracks: ultimate failure
Spar Cap
1. Axial Cracks
Adhesive
Web
Spar Cap
2. Start of
InterfaceFailure
Adhesive
Web
Spar Cap
Adhesive
3. Interface
Failure
Web
14
© Fraunhofer
Outlook: a new design path for rotor blades

Create extended standards
 IEA
 IEC-61400-5 Rotor blades
 IEC-61400-23 Testing or rotor blades
 Close cooperation with certification bodies
 DNV-GL
 DEWI-OCC
 Cooperation with industry

Steering committee
 Cooperation within (inter)national projects

EU projects

European Energy Research Alliance
16
© Fraunhofer
Steering
Committee
Acknowledgements
Fraunhofer IWES is funded by the:
Federal State of Bremen
Senator für Umwelt, Bau, Verkehr und Europa
Senator für Wirtschaft und Häfen
Senatorin für Bildung und Wissenschaft
Bremerhavener Gesellschaft für Investitions-Förderung und Stadtentwicklung GmbH
Federal State of Lower Saxony
Federal Republic of Germany
Federal Ministry for Economic Affairs and Energy (BMWi)
with support of the European Regional Development Fund (ERDF)
EUROPEAN UNION
Investing in your future
European Regional
Development Fund
Niedersachsen
34
© Fraunhofer
THANK YOU FOR
YOUR ATTENTION
Any questions?
[email protected]
35
© Fraunhofer