This paper presents a study combining additive manufactured (AM) elements with carbon fiber-reinforced polymers (CFRP) for the autoclave curing of complex-shaped, lightweight structures. Two approaches were developed: First, structural cores were produced with AM, over-laminated with CFRP, and co-cured in the autoclave. Second, a functional hull is produced with AM, filled with a temperature- and pressure-resistant material, and over-laminated with CFRP. After curing, the filler-material is removed to obtain a hollow lightweight structure. The approaches were applied to hat stiffeners, which were modeled, fabricated, and tested in three-point bending. Results show weight savings by up to 5% compared to a foam core reference. Moreover, the AM element contributes to the mechanical performance of the hat stiffener, which is highlighted by an increase in the specific bending stiffness and the first failure load by up to 18% and 310%. Results indicate that the approaches are appropriate for composite structures with complex geometries.

References

References
1.
Evans
,
A. G.
,
2001
, “
Lightweight Materials and Structures
,”
MRS Bull.
,
26
(
10
), pp.
790
797
.
2.
Davies
,
J. M.
,
2001
,
Lightweight Sandwich Construction
,
Wiley-Blackwell
,
Oxford, UK
.
3.
Herrmann, A. S.
,
Zahlen, P. C.
,
Zuardy, I.
, 2005, “
Sandwich Structures Technology in Commercial Aviation
,”
Sandwich Structures 7: Advancing with Sandwich Structures and Materials
, Thomsen, O., Bozhevolnaya, E., and Lyckegaard, A. eds., Springer, Dordrecht, The Netherlands.
4.
Anders
,
M.
,
Zebrine
,
D.
,
Centea
,
T.
, and
Nutt
,
S.
,
2017
, “
In Situ Observations and Pressure Measurements for Autoclave Co-Cure of Honeycomb Core Sandwich Structures
,”
ASME J. Manuf. Sci. Eng.
,
139
(
11
), p.
111012
.
5.
Kodiyalam
,
S.
,
Nagendra
,
S.
, and
DeStefano
,
J.
,
1996
, “
Composite Sandwich Structure Optimization With Application to Satellite Components
,”
AIAA J.
,
34
(
3
), pp.
614
621
.
6.
Huang
,
X.
, and
Xie
,
Y. M.
,
2008
, “
Optimal Design of Periodic Structures Using Evolutionary Topology Optimization
,”
Struct. Multidiscip. Optim.
,
36
(
6
), pp.
597
606
.
7.
Gibson
,
L. J.
, and
Ashby
,
M. F.
,
1999
,
Cellular Solids: Structure and Properties
,
Cambridge University Press
,
Cambridge, UK
.
8.
Huang
,
S. N.
, and
Alspaugh
,
D. W.
,
1974
, “
Minimum Weight Sandwich Beam Design
,”
AIAA J.
,
12
(
12
), pp.
1617
1618
.
9.
Li
,
X.
,
Li
,
G.
,
Wang
,
C. H.
, and
You
,
M.
,
2012
, “
Optimisation of Composite Sandwich Structures Subjected to Combined Torsion and Bending Stiffness Requirements
,”
Appl. Compos. Mater.
,
19
(
3–4
), pp.
689
704
.
10.
Catapano
,
A.
, and
Montemurro
,
M.
,
2014
, “
A Multi-Scale Approach for the Optimum Design of Sandwich Plates With Honeycomb Core—Part I: Homogenization of Core Properties
,”
Compos. Struct.
,
118
, pp.
664
676
.
11.
Catapano
,
A.
, and
Montemurro
,
M.
,
2014
, “
A Multi-Scale Approach for the Optimum Design of Sandwich Plates With Honeycomb Core—Part II: The Optimization Strategy
,”
Comp. Struct.
,
118
, pp.
677
690
.
12.
Krieglsteiner
,
J.
,
Horst
,
P.
, and
Schmidt
,
C.
,
2014
, “
Characterization of Fiber-Reinforced Stiffener Profiles for Aircraft Fuselage Preliminary Structural Design
,”
16th European Conference on Composite Materials
(
ECCM
), Seville, Spain, June 22–26, pp. 1–8.
13.
Tosh
,
M. W.
, and
Kelly
,
D. W.
,
2001
, “
Fibre Steering for a Composite C-Beam
,”
Comp. Struct.
,
53
(
2
), pp.
133
141
.
14.
Alinia
,
M. M.
, and
Moosavi
,
S. H.
,
2008
, “
A Parametric Study on the Longitudinal Stiffeners of Web Panels
,”
Thin-Walled Struct.
,
46
(
11
), pp.
1212
1223
15.
Kaufmann
,
M.
,
Zenkert
,
D.
, and
Mattei
,
C.
, 2008, “
Cost Optimization of Composite Aircraft Structures Including Variable Laminate Qualities
,”
Comp. Sci. Technol.
,
68
(
13
), pp.
2748
2754
.
16.
Mukhopadhyay
,
M.
,
2004
,
Mechanics of Composite Materials and Structures
,
University Press
,
Hyderguda
, India.
17.
Zenkert
,
D.
,
1995
,
An Introduction to Sandwich Construction
,
Engineering Materials Advisory Services
,
London
.
18.
Gutowski
,
T. G.
,
1997
,
Advanced Composites Manufacturing
,
Wiley
,
Cambridge, UK
.
19.
Advanced Ceramics Manufacturing, 2017, “
Advanced Ceramics Manufacturing
,” Tucson, AZ, accessed June 20, 2017, http://www.acmtucson.com
20.
Black
,
S.
,
2015
, “
3D Printing Moves Into Tooling Components
,” CompositesWorld, Cincinnati, OH, accessed June 15, 2017, https://www.compositesworld.com/articles/3d-printing-moves-into-tooling-components
21.
ASTM
,
2012
, “
Standard Terminology for Additive Manufacturing Technologies
,” West Conshohocken, PA, Standard No.
ASTM F2792-12a
.
22.
Stratasys
, 2017, “
Introduction to Additive Manufacturing for Composites
,” Stratasys, Eden Prairie, MN, accessed June 20, 2017, http://www.stratasys.com/de/campaign/ebook/additive-manufacturing-for-composites
23.
Li
,
H.
,
Taylor
,
G.
,
Bheemreddy
,
V.
,
Iyibilgin
,
O.
,
Leu
,
M.
, and
Chandrashekhara
,
K.
,
2015
, “
Modeling and Characterization of Fused Deposition Modeling Tooling for Vacuum Assisted Resin Transfer Molding Process
,”
Addit. Manuf.
,
7
, pp.
64
72
.
24.
Lušic
,
M.
,
Schneider
,
K.
, and
Hornfeck
,
R.
,
2016
, “
A Case Study on the Capability of Rapid Tooling Thermoplastic Laminating Moulds for Manufacturing of CFRP Components in Autoclaves
,”
Procedia CIRP
,
50
, pp.
390
395
.
25.
Prüß
,
H.
, and
Vietor
,
T.
,
2015
, “
Design for Fiber-Reinforced Additive Manufacturing
,”
ASME J. Mech. Des.
,
137
(
11
), p.
111409
.
26.
Hassen
,
A.
,
Lindahl
,
J.
,
Chen
,
J.
,
Post
,
B.
,
Love
,
L.
, and
Kunc
,
V.
,
2016
, “
Additive Manufacturing of Composite Tooling Using High Temperature Thermoplastic Materials
,”
SAMPE Conference Proceedings
, Long Beach, CA, May 23–26, pp.
2648
2658
.
27.
Stratasys
, 2017, “
Sacrificial Tooling and Mandrels Composite Part Fabrication—Design Guide
,” Stratasys, Eden Prairie, MN, accessed June 21, 2017, http://www.stratasys.com/solutions/additive-manufacturing/tooling/composite-tooling
28.
Türk
,
D.-A.
,
Triebe
,
L.
, and
Meboldt
,
M.
,
2016
, “
Combining Additive Manufacturing With Advanced Composites for Highly Integrated Robotic Structures
,”
Procedia CIRP
,
50
, pp.
402
407
.
29.
Nygaard
,
J. V.
, and
Lyckegaard
,
A.
,
2007
, “
Sandwich Beam With a Periodical and Graded Core Manufactured Using Rapid Prototyping
,”
J. Sandwich Struct. Mater.
,
9
(
4
), pp.
365
376
.
30.
Williams
,
R. R.
,
Howard
,
W. E.
, and
Martin
,
S. M.
,
2011
, “
Composite Sandwich Structures With Rapid Prototyped Cores
,”
Rapid Prototyping J.
,
17
(
2
), pp.
92
97
.
31.
Li
,
T.
, and
Wang
,
L.
,
2017
, “
Bending Behavior of Sandwich Composite Structures With Tunable 3D-Printed Core Materials
,”
Compos. Struct.
,
175
, pp.
46
57
.
32.
Morena
,
J. J.
,
2011
,
Mold Fabrications
,
Wiley Encyclopedia of Composites
, Hoboken, NJ.
33.
Bitzer
,
T.
,
2012
,
Honeycomb Technology: Materials, Design, Manufacturing, Applications and Testing
,
Springer Science & Business Media
, Dordrecht, The Netherlands.
34.
Stankunas
,
T.
,
Mazenko
,
D.
, and
Jensen
,
G.
,
1989
, “
Cocure Investigation of a Honeycomb Reinforced Spacecraft Structure
,”
21st International SAMPE Technical Conference
, Atlantic City, NJ, pp.
176
188
.
35.
Campbell
,
F. C.
, Jr.
,
2003
,
Manufacturing Processes for Advanced Composites
,
Elsevier
, Oxford, UK.
36.
ROHACELL
,
2017
, “
Rohacell IG-F Datasheet
,” Essen, Germany, accessed May 8, 2017, http://www.rohacell.com/sites/lists/RE/DocumentsHP/ROHACELL%20IG_IG-F%20Product%20Information.pdf
37.
Sigmund
,
O.
,
Aage
,
N.
, and
Andreassen
,
E.
,
2016
, “
On the (Non-)Optimality of Michell Structures
,”
Struct. Multidiscip. Optim.
,
54
(
2
), pp.
361
373
.
38.
Kussmaul
,
R.
,
Zogg
,
M.
, and
Ermanni
,
P.
,
2018
, “
An Optimality Criteria-Based Algorithm for Efficient Design Optimization of Laminated Composites Using Concurrent Resizing and Scaling
,”
Struct. Multidiscip. Optim.
(epub).
39.
Sriapai
,
T.
,
Walsri
,
C.
, and
Fuenkajorn
,
K.
,
2012
, “
Effect of Temperature on Compressive and Tensile Strength of Salt
,”
ScienceAsia
,
38
(
2
), pp.
166
174
.
40.
3D Systems
,
2017
, “
DuraForm HST Composite Datasheet
,” 3D Systems, Rock Hill, SC, accessed May 8, 2017, https://www.3dsystems.com/materials/duraform-hst-composite/tech-specs
41.
Schmid
,
M.
,
2015
,
Selektives Lasersintern (SLS) Mit Kunststoffen
,
Hanser
,
Munich, Germany
.
42.
Türk
,
D. A.
,
Brenni
,
F.
,
Zogg
,
M.
, and
Meboldt
,
M.
,
2017
, “
Mechanical Characterization of 3D Printed Polymers for Fiber Reinforced Polymers Processing
,”
Mater. Des.
,
118
, pp.
256
265
.
43.
Gere
,
J. M.
, and
Goodno
,
B. J.
,
2013
,
Mechanics of Materials
,
Cengage Learning
,
Stamford, CT
.
44.
Dewulf
,
W.
,
Pavan
,
M.
,
Craeghs
,
T.
, and
Kruth
,
J.-P.
,
2016
, “
Using X-Ray Computed Tomography to Improve the Porosity Level of Polyamide-12 Laser Sintered Parts
,”
CIRP Ann.
,
65
(
1
), pp.
205
208
.
45.
Shaw
,
B.
, and
Dirven
,
S.
,
2016
, “
Investigation of Porosity and Mechanical Properties of Nylon SLS Structures
,”
23rd International Conference on Mechatronics and Machine Vision in Practice
(
M2VIP
), Nanjing, China, Nov. 28–30, pp. 1–6.
46.
Ho
,
H. C. H.
,
Gibson
,
I.
, and
Cheung
,
W. L.
,
1999
, “
Effects of Energy Density on Morphology and Properties of Selective Laser Sintered Polycarbonate
,”
J. Mater. Process. Technol.
,
89–90
, pp.
204
210
.
47.
Rahman
,
K. M.
,
Hu
,
Z.
, and
Letcher
,
T.
,
2017
, “
In-Plane Stiffness of Additively Manufactured Hierarchical Honeycomb Metamaterials With Defects
,”
ASME J. Manuf. Sci. Eng.
,
140
(
1
), p.
011007
.
48.
Beyer
,
D.
, and
Figueroa
,
D.
,
2016
, “
Design and Analysis of Lattice for Additive Manufacturing
,”
ASME J. Manuf. Sci. Eng.
,
138
(
12
), p.
121015
..
49.
Schmidt
,
M.
,
Pohle
,
D.
, and
Rechtenwald
,
T.
,
2007
, “
Selective Laser Sintering of PEEK
,”
CIRP Ann. Manuf. Technol.
,
56
(
1
), pp.
205
208
.
50.
Fish
,
S.
,
Booth
,
J. C.
,
Kubiak
,
S. T.
,
Wroe
,
W. W.
,
Bryant
,
A. D.
,
Moser
,
D. R.
, and
Beaman
,
J. J.
,
2015
, “
Design and Subsystem Development of a High Temperature Selective Laser Sintering Machine for Enhanced Process Monitoring and Control
,”
Addit. Manuf.
,
5
, pp.
60
67
.
You do not currently have access to this content.