1. Grégoire Lepoittevin, Markus Zogg and Paolo Ermanni
COMPTEST 2011
TESTING OF MULTIFUNCTIONAL STRUCTURAL COMPOSITE COMPONENTS WITH INTEGRATED DAMPING TREATMENTS
Grégoire Lepoittevin, Markus Zogg
and Paolo Ermanni

2. Contents Multifunctional structures Demonstrator Mechanical tests
ETH ZÜRICH
Contents
Multifunctional structures
Demonstrator
Mechanical tests
Vibro-acoustic tests
Conclusion
CENTRE OF STRUCTURE TECHNOLOGIES

3. Contents Multifunctional structures Demonstrator Mechanical tests
ETH ZÜRICH
Contents
Multifunctional structures
Demonstrator
Mechanical tests
Vibro-acoustic tests
Conclusion
CENTRE OF STRUCTURE TECHNOLOGIES

4. Multifunctional structures
A structure can be defined as follows [1]
In addition to this primarily function, a structure can also fulfil others
Thermal management
Vibration damping
Sound insulation
Power distribution networks
Energy harvesting …
‘‘The fundamental function of a structure is to maintain a specified configuration, appropriately constraining and supporting other elements, typically transferring mechanical loads between the parts.’’
[1] G. S. Aglietti, C. W. Schwingshackl, and S. C. Roberts. Multifunctional structure technologies for satellite applications. The Shock and Vibration Digest, 39:381–391, 2007.

5. Multifunctional structures
This concept is commonly apply for spacecraft design

6. Multifunctional structures
With the use of composite materials, it is possible to add a soft layer in the laminate lay-up to increase the vibration damping performance of the structure.
The challenge is to propose a design guideline where the structure has both very good mechanical and vibration damping performances.
Damping layer
Composite laminates

7. Multifunctional structures
Design approach
The goal of this study to asses the effect of the damping layer on the mechanical and vibro-acoustic behaviour of a structural component.

8. Contents Multifunctional structures Demonstrator Mechanical tests
ETH ZÜRICH
Contents
Multifunctional structures
Demonstrator
Mechanical tests
Vibro-acoustic tests
Conclusion
CENTRE OF STRUCTURE TECHNOLOGIES

9. Demonstrator ETH ZÜRICH 07.11.2018
CENTRE OF STRUCTURE TECHNOLOGIES

10. Demonstrator Manufacturing - RTM Process
ETH ZÜRICH
Demonstrator Manufacturing - RTM Process
CENTRE OF STRUCTURE TECHNOLOGIES

11. Demonstrator Manufacturing - RTM Process
ETH ZÜRICH
Demonstrator Manufacturing - RTM Process
Process characteristics
Resin degasing under vacuum at 80 ºC for 30 min
Mold temperature during injection: 125 ºC
Injection under vacuum at 4 bar pressure
Curing at 180 ºC for 180 minutes under 3 bar pressure
CENTRE OF STRUCTURE TECHNOLOGIES

12. Contents Multifunctional structures Demonstrator Mechanical tests
ETH ZÜRICH
Contents
Multifunctional structures
Demonstrator
Mechanical tests
Vibro-acoustic tests
Conclusion
CENTRE OF STRUCTURE TECHNOLOGIES

13. Four-Point Bending Test Set-Up
ETH ZÜRICH
Mechanical tests
Four-Point Bending Test Set-Up
CENTRE OF STRUCTURE TECHNOLOGIES

14. Mechanical tests 4-point bending test results
ETH ZÜRICH
Mechanical tests 4-point bending test results
4180N
4622N
21.1mm
20.5mm
2520N
2420N
29.3mm
826N/mm
831N/mm
28.6mm
5442N
5344N
21.7mm
20.2mm
2466N
46.9mm
2954N
50.1mm
888N/mm
849N/mm
Higher torsional stiffness of the web and higher bending strength for the C-frame with damping treatment
CENTRE OF STRUCTURE TECHNOLOGIES

15. Mechanical tests ‘Step’ Test Set-Up ETH ZÜRICH 07.11.2018
CENTRE OF STRUCTURE TECHNOLOGIES

16. Mechanical tests Step test results - C-frame without damping layer
ETH ZÜRICH
Mechanical tests Step test results - C-frame without damping layer
CENTRE OF STRUCTURE TECHNOLOGIES

17. Mechanical tests Step test results - C-frame with damping layer
ETH ZÜRICH
Mechanical tests Step test results - C-frame with damping layer
Lower strength and stiffness for the C-frame with damping treatment
CENTRE OF STRUCTURE TECHNOLOGIES

18. Contents Multifunctional structures Demonstrator Mechanical tests
ETH ZÜRICH
Contents
Multifunctional structures
Demonstrator
Mechanical tests
Vibro-acoustic tests
Conclusion
CENTRE OF STRUCTURE TECHNOLOGIES

19. Mechanical tests Vibro-acoustic test step-up
ETH ZÜRICH
Mechanical tests Vibro-acoustic test step-up
CENTRE OF STRUCTURE TECHNOLOGIES

20. Mechanical tests Vibro-acoustic test results
ETH ZÜRICH
Mechanical tests Vibro-acoustic test results
FRF C-frame without damping
FRF C-frame with damping
CENTRE OF STRUCTURE TECHNOLOGIES

21. Contents Multifunctional structures Demonstrator Mechanical tests
ETH ZÜRICH
Contents
Multifunctional structures
Demonstrator
Mechanical tests
Vibro-acoustic tests
Conclusion
CENTRE OF STRUCTURE TECHNOLOGIES

22. Conclusion
The mechanical tests in 4-point bending reveal that the C-frame with damping as a higher stiffness and strength than the one without.
The ‘step’ tests shows that the C-frame without damping treatment has a higher stiffness and strength
The vibro-acoustic measurement campaign shows that the resonance frequencies of the C-frame with damping are higher than for the structure without damping.
Future works will aim at demonstrating the efficiency of multifuncional composites in comparison with a composite structure having a classical damping treatment.

23. THANK YOU FOR YOUR ATTENTION.
ANY QUESTIONS?