Mechanics of Composite, Hybrid and Multifunctional Materials , Volume 6: Proceedings of the 2020 Annual Conference on Experimental and Applied ... Society for Experimental Mechanics Series) 3030598675, 9783030598679

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Conference Proceedings of the Society for Experimental Mechanics Series

Raman P. Singh Vijay Chalivendra   Editors

Mechanics of Composite, Hybrid and Multifunctional Materials , Volume 6 Proceedings of the 2020 Annual Conference on Experimental and Applied Mechanics

Conference Proceedings of the Society for Experimental Mechanics Series Series Editor Kristin B. Zimmerman Society for Experimental Mechanics, Inc., Bethel, CT, USA

The Conference Proceedings of the Society for Experimental Mechanics Series presents early findings and case studies from a wide range of fundamental and applied work across the broad range of fields that comprise Experimental Mechanics. Series volumes follow the principle tracks or focus topics featured in each of the Society’s two annual conferences: IMAC, A Conference and Exposition on Structural Dynamics, and the Society’s Annual Conference & Exposition and will address critical areas of interest to researchers and design engineers working in all areas of Structural Dynamics, Solid Mechanics and Materials Research.

More information about this series at http://www.springer.com/series/8922

Raman P. Singh • Vijay Chalivendra Editors

Mechanics of Composite, Hybrid and Multifunctional Materials, Volume 6 Proceedings of the 2020 Annual Conference on Experimental and Applied Mechanics

Editors Raman P. Singh Engineering, Architecture & Technology Oklahoma State University, College of Stillwater, OK, USA

Vijay Chalivendra University of Massachussetts North Dartmouth, MA, USA

ISSN 2191-5644 ISSN 2191-5652 (electronic) Conference Proceedings of the Society for Experimental Mechanics Series ISBN 978-3-030-59867-9 ISBN 978-3-030-59868-6 (eBook) https://doi.org/10.1007/978-3-030-59868-6 © The Society for Experimental Mechanics, Inc. 2021 This work is subject to copyright. All rights are solely and exclusively licensed by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed. The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The publisher, the authors, and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, expressed or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. This Springer imprint is published by the registered company Springer Nature Switzerland AG The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

Preface

Mechanics of Composite, Hybrid and Multifunctional Materials represents one of seven volumes of technical papers presented at the 2020 SEM Annual Conference and Exposition on Experimental and Applied Mechanics organized by the Society for Experimental Mechanics held in Orlando, FL, September 14–17, 2020. The complete Proceedings also includes volumes on Dynamic Behavior of Materials; Challenges in Mechanics of Time-Dependent Materials, Fracture, Fatigue, Failure and Damage Evolution; Advancement of Optical Methods & Digital Image Correlation in Experimental Mechanics; Mechanics of Biological Systems and Materials, Micro- and Nanomechanics & Research Applications; and Thermomechanics & Infrared Imaging, Inverse Problem Methodologies and Mechanics of Additive & Advanced Manufactured Materials. The commercial market for composite continues to expand with a wide range of applications from sporting equipment to aerospace vehicles. This growth has been fueled by new material developments, greater understanding of material behaviors, novel design solutions, and improved manufacturing techniques. The broad range of applications and the associated technical challenges require an increasingly multidisciplinary and collaborative approach between the mechanical, chemical, and physical sciences to sustain and enhance the positive impact of composites on the commercial and military sectors. New materials are being developed from recycled source materials, leading to composites with unique properties and more sustainable sources. Existing materials are also being used in new and critical applications, which require a deeper understanding of material behaviors and failure mechanisms on multiple length and time scales. In addition, the unique properties of composites present many challenges in manufacturing and in joining with other materials. New testing methods must be developed to characterize the novel composite properties, to evaluate application and product life cycle performance, as well as to evaluate impacts and merits of new manufacturing methods. This volume presents early research findings from experimental and computational investigations related to the processing, characterization, and testing of composite, hybrid, and multifunctional materials. Stillwater, OK, USA Dartmouth, MA, USA

Raman P. Singh Vijaya Chalivendra

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Contents

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Autonomous Healing and Indication of Transverse Crack Damage in Carbon Fiber Composite Laminates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Kelly M. Chang and Nancy R. Sottos

1

A Novel Test Geometry for Characterization of Traction-Separation Behavior in Composite Laminates Under Mode I Delamination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Devon C. Hartlen, John Montesano, and Duane S. Cronin

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Design of Recycled Alumix-123 Based Composites Reinforced with γ-Al2O3 through Combined Method; Sinter + Forging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F. Gatamorta, H. M. Enginsoy, E. Bayraktar, I. Miskioglu, and D. Katundi

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Compressive Behavior of AlSiMg0.5Mn Matrix Syntactic Foam Produced via Thixoinfiltration of Fly Ash Micro Balloons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J. P. Paschoal, R. C. Moraes, E. Bayraktar, J. Sartori, R. Silva, and F. Gatamorta

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Tailored Behaviour of Scrap Copper Matrix Composites Reinforced with Zinc and Aluminium: Low Cost Shape Memory Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L. Mihlyuzova, H. M. Enginsoy, D. Dontchev, and E. Bayraktar

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New Design of Composites from Fresh Scraps of Niobium for Tribological Applications . . . . . . . . . . . . . . E. Bayraktar, F. Gatamorta, H. M. Enginsoy, J. E. Polis, and I. Miskioglu

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Design of Copper and Silicon Carbide (SiC) Reinforced Recycled Aluminium Matrix Composites Through Sintering + Forging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H. M. Enginsoy, F. Gatamorta, E. Bayraktar, I. Miskioglu, and A. Larbi

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Manufacturing of “Ni-Ti” Based Composites from Fresh Scrap Thin Sheets Reinforced with Nb and TiB2 Through Hot-Forged Bonding: Sandwich Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . H. M. Enginsoy, E. Bayraktar, I. Miskioglu, and D. Katundi

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Design Study of Morphing Wing with MFC Actuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. M. Mennu, B. Tran, C. S. Tripp, and P. G. Ifju

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Design of Recycled Thin Sheet “Ti-Al” Based Composites Reinforced with AA1050, Boron, TiB2, TiC, and B4C Through Hot-Forged Bonding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . E. Bayraktar, D. Katundi, F. Gatamorta, I. Miskioglu, and H. Murat Enginsoy

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Design of Copper and γ-Alumina Reinforced Recycled Aluminium Matrix Composites through Sintering + Forging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . H. M. Enginsoy, E. Bayraktar, I. Miskioglu, F. Gatamorta, and D. Katundi

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Experimental Study on Compressive Strength of Copper Slag Replaced Cement Concrete . . . . . . . . . . . . G. L. Easwara Prasad, B. S. Keerthi Gowda, and R. Velmurugan

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Enhanced Structural Imperfection Resistance in Thin-Walled Tubes Filled with Liquid Nanofoam . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mingzhe Li, Fuming Yang, and Weiyi Lu

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Time Temperature Superposition Shift Factors for Fabric Composites . . . . . . . . . . . . . . . . . . . . . . . . . . . Brian T. Werner and Kevin Nelson

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Applying Macro Fiber Composite Patches to Morph Complex Aircraft Structure . . . . . . . . . . . . . . . . . . . B. Tran, P. G. Ifju, M. M. Mennu, A. Brenes, and S. Shbalko

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Study of a Semisolid Processing Route for Producing an AlSiMg0.5Mn Matrix Syntactic Foam via Thixoinfiltration of Fly Ash Micro Balloons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 R. C. Moraes, J. P. Paschoal, E. Bayraktar, R. Silva, R. Costa, and F. Gatamorta

Chapter 1

Autonomous Healing and Indication of Transverse Crack Damage in Carbon Fiber Composite Laminates Kelly M. Chang and Nancy R. Sottos

Abstract The performance of fiber-reinforced polymer (FRP) composites is limited by susceptibility to transverse microcracking and interfacial debonding. In this work, we introduce a microcapsule-based self-reporting and self-healing strategy for simultaneous detection and repair of cracks in FRPs. This dual functionality is achieved via the microencapsulation of a solvent-based healing agent doped with aggregation induced emission (AIE) luminogens and the subsequent dispersion of such microcapsules in carbon prepreg containing a thermoplastic-toughened epoxy matrix. Composite specimens are fabricated with a [0/90/0] stacking sequence from self-healing prepreg tapes and loaded in transverse tension until crack saturation is achieved. The transverse cracks rupture the microcapsules and release of the encapsulated solvent into the crack plane. Crack healing is achieved by the dissolution and redistribution of thermoplastic-rich regions into the damage volume. Evaporation of the solvent leaves solid thermoplastic in place of the crack and allowing AIE luminogens to aggregate and fluoresce. Using a small load frame that mounts under an optical microscope, we measure full-field surface strains during loading of the composite specimens via digital image correlation (DIC). The self-reporting functionality is evaluated by correlating the presence of microcracks with regions of damage-induced fluorescence. The healing efficiency of the composite specimens is assessed by comparing the applied stress levels and strain fields associated with cracking events pre- and posthealing.

1.1

Introduction

Glass-fiber and carbon-fiber reinforced polymers (GFRPs and CFRPs) are used widely in high-performance applications for their high stiffness, specific strength, chemical resistance, and low thermal sensitivity. However, FRPs are prone to fatigueinduced failure, which is often due to transverse cracking or interfacial de-bonding. As a result, FRPs often fail catastrophically under stresses significantly lower than their quasi-static strengths, motivating the need for self-reporting and self-healing strategies to both detect and repair cracks before failure. This dual functionality has powerful implications in extending the safe and usable lifespan of vehicles and load-bearing structures for aerospace and defense applications. While self-healing can provide in-situ damage control, additional and simultaneous self-reporting functionality can indicate where the healing functionality has already been spent, thereby informing users of the most vulnerable regions before impending failure occurs.

1.2

Background

Biologically inspired self-healing polymers and FRP composites have the ability to autonomously detect and repair damage [1–3]. In capsule-based systems, an autonomous healing reaction is triggered by rupturing an embedded microencapsulated healing agent, which reacts with the matrix to heal the damaged volume. This approach to self-healing is effective for damage at the microscale [4]. Furthermore, it has been shown that incorporating solvent-filled microcapsules (polydopamine-coated polyurethane/urea-formaldehyde triple-walled shell wall with ethyl phenylacetate core (PDA(PU/UF(EPA))) slowed the fatigue-induced decay of stiffness in GFRP and CFRP composites [3]. These PDA(PU/UF(EPA)) capsules were successfully embedded into fiber bundles via the traditional prepreg method used in industry [3]. K. M. Chang (*) · N. R. Sottos Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, USA e-mail: [email protected]; [email protected] © The Society for Experimental Mechanics, Inc. 2021 R. P. Singh, V. Chalivendra (eds.), Mechanics of Composite, Hybrid and Multifunctional Materials, Volume 6, Conference Proceedings of the Society for Experimental Mechanics Series, https://doi.org/10.1007/978-3-030-59868-6_1

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Autonomous damage indication in coatings has been achieved via encapsulated AIE luminogens [5, 6]. AIE is the only proven method that does not rely on auxiliary material constituents—an advantage attributable to the unique properties of AIE molecules. In solution, AIE luminogens can relax absorbed photon energy non-radiatively due to their vibrational and rotational modes. Upon capsule rupture and solvent evaporation, aggregation of these AIE luminogens restricts the intramolecular motions required to relax the absorbed photon energy and triggers localized photoluminescence [5]. In this work, we successfully incorporate microencapsulated AIE luminogens into fiber reinforced composites.

1.3

Results

Composite self-healing and self-reporting capabilities were assessed separately before combining both functionalities into one material system. Self-healing composites were fabricated by incorporating solvent-only microcapsules into a cross-ply CFRP with a thermoplastic-toughened epoxy matrix. The composite layup was hot-pressed at 120  C under 0.3 MPa for 3 h, followed by 180  C under 0.3 MPa for 1 h with a temperature ramp rate of 1  C/min between steps. After cooling to room temperature, the panel was post-cured in an oven at 180  C for 1 h. SEM was used to estimate capsule volume fraction in the composite and to also confirm that the microcapsules survived both pre-pregging and hot-pressing. Final composites had a fiber volume fraction of 51%, estimated capsule volume fraction of 1%, and Tg of 172  C. Tensile specimens were cut from processed panels with dimensions of 1.2  2.5  15 mm and the cross-section was polished. Specimens were loaded in transverse tension in a xyz load frame mounted under a digital optical microscope (Keyence VHX-5000). DIC was performed on these specimens during loading and a representative strain field is shown in Fig. 1.1. Healing is assessed by comparing the stress-strain response of the damaged composites pre- and post-healing. Self-reporting composites were produced by incorporating AIE-doped solvent microcapsules into a cross-ply CFRP with an Araldite LY 8605 epoxy matrix (no thermoplastic phase). Self-reporting composite layups were hot-pressed at room temperature for 24 h under 0.3 MPa, followed by 2 h at 121  C under 0.3 MPa, and a final 3 h at 177  C under 0.3 MPa. As described above, capsule volume fraction and capsule survival were evaluated by SEM. Final self-reporting composites had a fiber volume fraction of 53%, estimated capsule volume fraction of 1%, and Tg of 150  C. Self-reporting FRP tensile specimens were loaded in transverse tension until crack saturation occurred. Optical microscopy was used to characterize localized fluorescence near the cracked regions.

1.4

Conclusion

Autonomous healing and reporting were demonstrated separately in CFRPs. Self-healing and self-reporting composites were fabricated with a 54% fiber volume fraction and estimated capsule volume fraction of 1%. The microcapsules survived the cure cycle and were shown to rupture under transverse tensile loading. Tensile tests with DIC were successfully performed on self-healing samples and found to have a 4% local strain to failure before healing. Successful damage indication was demonstrated in neat epoxy specimens. Future tests are planned to assess local post-healing mechanical properties. We also plan to assess simultaneous self-healing and self-reporting by correlating local fluorescence with local recovery in mechanical properties.

Fig. 1.1 Surface strain map of a carbon-fiber specimen with two transverse cracks. Surface strain field is determined via DIC

1 Autonomous Healing and Indication of Transverse Crack Damage in. . .

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Acknowledgements This work was supported as part of the AFOSR Center of Excellence in Self-Healing, Regeneration and Remodeling, award FA9550-16-1-0017. We would also like to acknowledge Dr. Sang Yup Kim for helpful suggestions, undergraduate researchers Alexander Kosyakov, Enola Ma, and Aiden Kamber for microcapsule synthesis and characterization, and use of the Imaging Technology group and shared user facilities at the University of Illinois Beckman Institute.

References 1. Jones, A.R., Watkins, C.A., White, S.R., Sottos, N.R.: Self-healing thermoplastic-toughened epoxy. Polymer (Guildf). 74, 254–261 (2015) 2. Jones, A.S., Rule, J.D., Moore, J.S., Sottos, N.R., White, S.R.: Life extension of self-healing polymers with rapidly growing fatigue cracks. J. R. Soc. Interface. 4(13), 395–403 (2007) 3. Kim, S.Y.: Self-healing laminated composites from prepreg fabrics. Dissertation, University of Illinois at Urbana-Champaign (2017) 4. White, S.R., Caruso, M.M., Moore, J.S.: Autonomic healing of polymers. MRS Bull. 33(08), 766–769 (2008) 5. Robb, M.J., et al.: A robust damage-reporting strategy for polymeric materials enabled by aggregation-induced emission. ACS Cent. Sci. 2, 598–603 (2016) 6. Li, W., Matthews, C.C., Yang, K., Odarczenko, M.T., White, S.R., Sottos, N.R.: Autonomous indication of mechanical damage in polymeric coatings. Adv. Mater. 28(11), 2189–2194 (2016)

Chapter 2

A Novel Test Geometry for Characterization of Traction-Separation Behavior in Composite Laminates Under Mode I Delamination Devon C. Hartlen, John Montesano, and Duane S. Cronin

Abstract The integration of composite laminates into automotive structures can provide weight reduction and improvement in occupant safety. However, the adoption of such materials requires characterization and efficient modeling of the damage behaviors of composite laminates which may occur during crash events, such as delamination. Numerical modeling techniques such as cohesive zone modeling require a traction-separation response for each mode of loading. The standard test technique used to characterize Mode I delamination, the double cantilever beam (DCB), measures the critical energy release rate; however, additional tests or inverse fitting techniques are required to characterize the full traction-separation response. Additionally, compliance inherent in the DCB specimen can influence the measured energy release rate while the large size of the specimen complicates the high deformation rate testing needed for crash analysis. In this study, a novel Mode I test specimen adapted from a recent advancement in structural adhesive characterization is applied to evaluate composite delamination. The hybrid Rigid Double Cantilever Beam (RDCB) test specimen presented herein consists of rigid steel adherends co-molded to a composite plate containing a crack initiator. The use of steel adherends eliminates compliance in the composite laminate and ensures the interface of interest is loaded consistently and uniformly during tests, enabling measurement of the Mode I traction-separation behavior of composite delamination in a single test. As an example, the hybrid RDCB geometry is used to characterize the Mode I delamination behavior of a unidirectional E-glass fiber/epoxy laminate under quasi-static conditions, highlighting the ability of this specimen geometry to extract a full tractionseparation behavior from a single test.

2.1

Introduction and Background

With increasingly strict emission limits placed on automotive manufacturers, there is a push toward integrating lightweight materials such as fiber-reinforced polymers (FRPs) into production automobiles to reduce vehicle weight and increase fuel efficiency [1]. In addition to being lightweight, FRPs also have greater stiffness-to-weight and energy absorption properties compared to traditional steel components [2]. However, their adoption is slowed, in part, due to a lack of maturity in modeling the damage accumulation and failure modes of composite materials that may occur in extreme events such as impact or crash scenarios. One modeling approach being investigated to predict the delamination behavior of FRP components is cohesive zone modeling (CZM). However, a traction-separation law (TSL) representing the material response of the FRP is required when using CZM, which further necessitates characterizing the delamination behavior of the FRP. The de facto method for characterizing Mode I delamination is the double cantilever beam (DCB) test [3]. While widely used and studied, the DCB test is only capable of directly measuring the Mode I critical energy release rate (CERR) of the FRP. Additional tests or inverse fitting techniques are needed to extract the mechanical properties required to define the TSL for a specific material fully. Furthermore, the compliance of the DCB specimen can affect the calculation of CERR in some data reduction schemes or test conditions [4]. One approach to mitigate the issue of DCB specimen compliance developed by Marzi et al. [4] was to bond aluminum bars to the top and bottom of composite DCB specimens to increase specimen rigidity. While this improves the measurement of CERR, inverse methods are still required to extract other TSL parameters. However, a recent advancement in the characterization of adhesive behavior presents a potential alternative to the DCB test. The rigid double cantilever beam (RDCB) specimen and analysis technique presented by Watson et al. [5] makes use of metallic adherends, which are effectively rigid compared to the interface material being testing. This rigidity makes it possible to extract the full traction-separation response

D. C. Hartlen (*) · J. Montesano · D. S. Cronin Department of Mechanical and Mechatronic Engineering, University of Waterloo, Waterloo, ON, Canada e-mail: [email protected]; [email protected]; [email protected] © The Society for Experimental Mechanics, Inc. 2021 R. P. Singh, V. Chalivendra (eds.), Mechanics of Composite, Hybrid and Multifunctional Materials, Volume 6, Conference Proceedings of the Society for Experimental Mechanics Series, https://doi.org/10.1007/978-3-030-59868-6_2

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Fig. 2.1 RDCB specimen geometry; adherends shown in grey, composite in yellow. The thickness of the composite (yellow) is not to scale. All units are millimeters

of an interface from a single test. Additionally, the small size and low inertia of the RDCB specimen make it suitable for high deformation rate testing. In this study, the RDCB specimen geometry was investigated to characterize the Mode I delamination of a unidirectional E-glass fibre/epoxy laminate.

2.2

Methodology

The adherends of the hybrid RDCB specimen (Fig. 2.1) were machined from mild steel. The co-molding surfaces of the adherends were grit-blasted with 60 grit silicon carbide blasting media to roughen the surfaces and promote good adhesion between the composite laminate and adherends as well as promoting crack development between the composite plies. Two-ply unidirectional composite laminates ([0]2) were individually processed to fit between the bonding surfaces of the metallic adherends using a unidirectional prepreg material (UE400-REM, Composite Materials, Italy). A 12.5 μm thick PTFE film was placed between the plies of the laminate to provide a crack initiator. The laminate was cured between two metallic  RDCB adherends under 5 bar of pressure at 140 C for 90 min in a specially designed jig to ensure the alignment of the adherends and consistent thickness of the composite. This processing technique not only cured the prepreg material but also molded the FRP directly to the metallic adherends. After processing, cured resin spew and excess composite material were removed from the specimen using abrasive paper. All specimens were imaged using an optical-digital microscope to verify the overall dimensions of each specimen as well as to measure the length of the pre-crack formed by the PTFE tape. A hydraulic test frame was used to test specimens to failure at a constant crosshead speed of 0.025 mm/s. Tests were imaged at 1080p resolution and 30 frames per second using a Nikon D3200 camera fitted with a 105 mm macro lens and 2 teleconverter. The displacement of the pins used to load the specimen was tracked optically using open source software (Tracker, Open Source Physics, National Science Foundation) [6] to eliminate the effects of machine compliance. Tractionseparation behavior was extracted from the test data using the method described by Watson et al. [5]. A bi-linear TSL was then fit to the response of each specimen. The TSL is described using three parameters: interface stiffness (E), peak traction (σ max), and critical energy release rate (GI, C).

2.3

Results and Discussion

The force-displacement behavior (Fig. 2.2) of the five hybrid RDCB specimens tested in this study showed that force trended linearly with adherend displacement, with a plateau at the average peak force of 650 N before failure. However, it is important to note that this plateau occurred over a very brief period of time, and force-displacement data was sparse in this region. This

2 A Novel Test Geometry for Characterization of Traction-Separation. . .

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Fig. 2.2 Force-displacement responses of hybrid RDCB tests for Mode I composite delamination. The plateau region is highlighted in yellow

plateau could indicate damage propagation within the delamination interface prior to abrupt crack growth and subsequent loss of load-carrying capacity. The sparse force-displacement data in the plateau does limit how accurately this potential damage accumulation can be characterized, however. Interface stiffness and peak force were consistent among specimens, although displacement to failure demonstrated variability, ranging between 0.12 and 0.15 mm. The analysis technique developed by Watson et al. [5] relies on the derivative of the force-displacement response to calculate traction-separation behavior. Given the non-smooth nature of the experimental force-displacement data, filtering was required to produce and calculate an accurate, realistic derivative. This filtering did introduce some oscillatory features into the calculated traction-separation response (Fig. 2.3). Nonetheless, traction-separation behavior closely mirrored forcedisplacement behavior, with traction increasing linearly with interface separation up to peak traction. The sparsity of data in the force-displacement plateau region lead to the associated plateau of the traction-separation responses being somewhat lower than the maximum computed traction. However, this calculation would likely improve with more temporal resolution in that region. The quality of the fitted TSLs (Fig. 2.3) was somewhat compromised as a bi-linear curve was unable to capture the plateau region of the extracted traction-separation responses. A trapezoidal TSL would likely provide a better representation of the delamination response for this material. Regardless, average fitted parameters (Table 2.1) exhibited a low degree of variation between specimens, particularly for interface stiffness and peak traction (less than 10% variation). Work conducted by Marat-Medes and Freitas [7] measured the mode I CERR of a composite laminate processed from the same prepreg material used in the present study to be 0.85 kJ/mm2 using conventional DCB tests. This value is lower than the value of CERR determined from the hybrid RDCB test (1.98 kJ/mm2). While this difference could be attributed, in part, due to differences in processing method and parameters, Watson et al. also demonstrated the RDCB produced larger values of CERR than traditional DCB testing techniques [5]. Watson et al. attributed this to the rigidity of the RDCB adherends, which stores less deformation energy during testing than the DCB geometry and loads the interface of interest more uniformly.

2.4

Conclusions and Future Work

The RDCB specimen, originally developed for the characterization of adhesives, has been shown in this work to be capable of characterizing the Mode I delamination behavior of FRPs. A full traction-separation response was extracted from a single test geometry, with experimental tests exhibiting low variation, particularly in stiffness and peak traction. Future work will

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Fig. 2.3 Calculated traction-separation responses (blue curves) for each test (grey curves), plotted with the average TSL (yellow curve)

Table 2.1 TSL constitutive model parameters averaged over all specimens. Standard deviation provided in parenthesis Parameter Value

E (GPa) 1482 (80)

σ peak (MPa) 57.5 (3.4)

GI, C (kJ/m2) 1.98 (0.32)

investigate improving the experimental setup to improve the resolution of force-displacement response, particularly in the plateau region prior to failure to characterize damage propagation better. Follow-on work will apply the hybrid RDCB geometry to study high deformation rate, Mode I delamination response as well as the fitting of a trapezoidal TSL to material behavior. Acknowledgments The authors would like to thank the support of the Ontario Advanced Manufacturing Consortium and the Natural Science and Engineering Research Council of Canada for financial support in this project.

References 1. Tabiei, A., Zhang, W.: Composite laminate delamination simulation and experiment: a review of recent development. Appl. Mech. Rev. 70(3), 030801 (2018). https://doi.org/10.1115/1.4040448 2. Machado, J., Marques, E., Campilho, R., da Silva, L.F.: Mode I fracture toughness of CFRP as a function of temperature and strain rate. J. Compos. Mater. 51(23), 3315–3326 (2017). https://doi.org/10.1177/0021998316682309 3. ASTM International: ASTM D5528-13 Standard test method for mode I interlaminar fracture toughness of unidirectional fiber-reinforced polymer matrix composites. West Conshohocken, PA (2013) 4. Marzi, S., Rauh, A., Hinterhölzl, R.M.: Fracture mechanical investigations and cohesive zone failure modeling on automotive composites. Compos. Struct. 111, 324–331 (2014). https://doi.org/10.1016/j.compstruct.2014.01.016 5. Watson, B., Liao, C.-H., Worswick, M.J., Cronin, D.S.: Mode I traction-separation measured using rigid double cantilever beam applied to structural adhesive. J. Adhes., 1–21 (2018). https://doi.org/10.1080/00218464.2018.1502666 6. Brown, D.: Tracker video analysis and modeling tool V5.1.3.” [Computer Software]. http://physlets.org/tracker/ (2019) 7. Marat-Mendes, R.M., Freitas, M.M.: Failure criteria for mixed mode delamination in glass fibre epoxy composites. Compos. Struct. 92(9), 2292–2298 (2010). https://doi.org/10.1016/j.compstruct.2009.07.017

Chapter 3

Design of Recycled Alumix-123 Based Composites Reinforced with γ-Al2O3 through Combined Method; Sinter + Forging F. Gatamorta, H. M. Enginsoy, E. Bayraktar, I. Miskioglu, and D. Katundi

Abstract Aluminium Metal Matrix Composites (AMMCs) have very light weight, high strength, and show better resistance to corrosion, oxidation, and wear. Impact resistance is an especially important property of these AMMCs which is essential for automotive applications. In this study, recycled aluminium matrix composites were designed through the powder metallurgy route. As matrix, fresh scrap aluminium chips (Alumix-123), by-product of machining coming from the French aeronautical company, were used. Fine -alumina particles (γ-Al2O3, 10 wt %), were used as main reinforcement element for the present work. As secondary reinforcements, Mo and Cu were added in the matrix. In this study, a typical low cost but high performance metal matrix composite was designed by using recycled aluminum chips (Alumix-123). This process comprises of the mixing, blending and compacting of aluminum chips through press moulding and pre-sintering and finally forging. In the final stage, material parameters were optimized for improving physical and mechanical properties of these composites. Further, the influence of reinforcement’s type and content on the mechanical properties has also been reviewed and discussed. Damping capacities and damage were analysed by drop weight and quasi static compression tests. Microstructures were analysed by the Scanning Electron Microscope (SEM).

3.1

Introduction

Aluminium based hybrid composites are the most demanding aeronautical and aerospace operational applications. During the last decades, these composites are also very attractive for the automotive industry. Regarding to other manufacturing processes such as casting machining, etc. manufacturing via powder metallurgy (PM) route are the high performance process for producing net-shaped parts because of the facilities of the production of fully dense, low cost composites by using of sintering and hot pressing/forging with sound and healthy microstructure [1–7]. Wear and impact loading are the most important problems encountered in many industrial applications. Many different solution approaches have been developed for the solution of these problems encountered in applications [4–9]. Developing new generation materials that will resist wear and impact loads and developing new manufacturing methods for these materials are among the most important of these solutions [6–13]. (Alumix-123), by-product of machining coming from the French aeronautical company, were used. This process comprises the mixing, blending and compacting of aluminum F. Gatamorta University of Campinas-UNICAMP-FEM, Campinas, São Paulo, Brazil e-mail: [email protected] H. M. Enginsoy Supmeca-Paris, School of Mechanical and Manufacturing Engineering, Paris, France Usak University, School of Mechanical Engineering, Usak, Turkey E. Bayraktar (*) University of Campinas-UNICAMP-FEM, Campinas, São Paulo, Brazil Supmeca-Paris, School of Mechanical and Manufacturing Engineering, Paris, France e-mail: [email protected] I. Miskioglu Michigan Technological University ME-EM Department, Houghton, MI, USA e-mail: [email protected] D. Katundi Supmeca-Paris, School of Mechanical and Manufacturing Engineering, Paris, France e-mail: [email protected] © The Society for Experimental Mechanics, Inc. 2021 R. P. Singh, V. Chalivendra (eds.), Mechanics of Composite, Hybrid and Multifunctional Materials, Volume 6, Conference Proceedings of the Society for Experimental Mechanics Series, https://doi.org/10.1007/978-3-030-59868-6_3

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chips through press moulding and pre-sintering and finally forging. In the final stage, material parameters were optimized for improving physical and mechanical properties of these composites [3, 7, 9–15]. In this study, a typical low cost but high performance metal matrix composite was designed by using recycled aluminum chips (Alumix-123) as matrix material as fine γ-alumina particles main reinforcement element Cu and Mo as secondary reinforcement element. For the characterization of this composite, Static compression test drop weight (impact) test and also nano wear and nano creep tests have been carried out. Chemical and microstructural analyses, the internal structure of the material was analyzed in detail with Scanning Electron Microscope (SEM).

3.2

Experimental Conditions

In the frame of a common research project, an alternative low cost aluminium matrix composite (AMCs) was designed from the fresh scrap recycled chips of the aluminium series of Alumix-123 given by aeronautic company. After atomization process of the fresh scarp were premixed by using high energy milling in a planetary ball mill during 1 h and doped with copper/γ Alumina (Al2O3). The final composition was homogenized by ball milling during the 4 hours. For obtaining a homogenous mixture with fast wettability of the reinforcements to the matrix, pure nano aluminium (