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A methodology to conduct Push-Out tests to evaluate the degradation in interfacial shear strength of Carbon fiber/ Vinyl Ester composites due to long-term exposure to seawater.


Title: A methodology to conduct Push-Out tests to evaluate the degradation in interfacial shear strength of Carbon fiber/ Vinyl Ester composites due to long-term exposure to seawater.

Authors: V. Chawla, S. Puplampu, D. Penumadu

DOI: 10.33599/nasampe/c.23.0167

Abstract: In this study, single fiber (~7-micron diameter) push-out tests are conducted to evaluate hygrothermal effects on the interfacial shear strength (IFSS) of carbon fiber/vinyl ester (CF/VE) composites. Saturated samples are prepared by soaking the coupons in simulated seawater at 40°C for two years. A thorough investigation is carried out on the push-out test results' preparation, validity, and interpretation. Firstly, a polishing methodology is presented that consistently yields thin films of CF/VE composites in the thickness range of 15 to 120 microns. The results show a 41.2 percent drop in IFSS due to long-term hygrothermal exposure. Using scanning electron microscopy (SEM), the authors show that during the push-out tests, the failure initiates locally at the zone of minimum bond strength at the bottom (away from the indenter), then propagates along the length of the interface. Through a series of tests conducted at different interface thicknesses, the authors validate that the influence of radial tensile stresses originating due to bending is negligible. Using the SEM imaging of the pushed-out fibers, the authors show that the interfacial failure, not the matrix shear failure, is the primary source of deformation in push-out deformation. Furthermore, the results are shown to be dependent upon the interfacial volume indicating failure characteristics of Weibull weakest link theory.

References: [1] P. Bajpai, Update on Carbon Fibre, 2013. [2] S. Awasthi, J.L. Wood, Carbon/Carbon Composite Materials for Aircraft Brakes, 560 (2008) 553–559. doi:10.1002/9780470310496.ch4. [3] A. Siriruk, D. Penumadu, Y. Jack Weitsman, Effect of sea environment on interfacial delamination behavior of polymeric sandwich structures, Compos. Sci. Technol. 69 (2009) 821–828. doi:10.1016/j.compscitech.2008.02.033. [4] A. Siriruk, D. Penumadu, Degradation in fatigue behavior of carbon fiber-vinyl ester based composites due to sea environment, Compos. Part B Eng. 61 (2014) 94–98. doi:10.1016/j.compositesb.2014.01.030. [5] E. Fitzer, L. Manocha, Carbon Reinforcements and carbon/carbon composites., in: New York, 1998: p. 73. [6] B. Pukánszky, Influence of interface interaction on the ultimate tensile properties of polymer composites, Composites. 21 (1990) 255–262. doi:10.1016/0010-4361(90)90240-W. [7] J. Koyanagi, H. Hatta, M. Kotani, H. Kawada, A comprehensive model for determining tensile strengths of various unidirectional composites, J. Compos. Mater. 43 (2009) 1901–1914. doi:10.1177/0021998309341847. [8] C.R. Schultheisz, A.M. Waas, Compressive failure of composites, Part I: Testing and micromechanical theories, Prog. Aerosp. Sci. 32 (1996) 1–42. doi:10.1016/0376-0421(94)00002-3. [9] S. Drapier, M.R. Wisnom, Finite-element investigation of the compressive strength of non-crimp-fabric-based composites, Compos. Sci. Technol. 59 (1999) 1287–1297. doi:10.1016/S0266-3538(98)00165-1. [10] A.M. Waas, C.R. Schultheisz, Compressive failure of composites, Part II: Experimental studies, Prog. Aerosp. Sci. 32 (1996) 43–78. doi:10.1016/0376-0421(94)00003-4. [11] M.O.W. Richardson, M.J. Wisheart, Review of low-velocity impact properties of composite materials, Compos. Part A Appl. Sci. Manuf. 27 (1996) 1123–1131. doi:10.1016/1359-835X(96)00074-7. [12] L. Sorrentino, D.S. de Vasconcellos, M. D’Auria, F. Sarasini, J. Tirillò, Effect of temperature on static and low velocity impact properties of thermoplastic composites, Compos. Part B Eng. 113 (2017) 100–110. doi:10.1016/j.compositesb.2017.01.010. [13] S. Feih, K. Wonsyld, D. Minzari, P. Westermann, H. Lilholt, Testing procedure for the single fiber fragmentation test, 2004. [14] C. Medinam, J.M. Molina-Aldareguía, C. González, M.F. Melendrez, P. Flores, J. Llorca, Comparison of push-in and push-out tests for measuring interfacial shear strength in nano-reinforced composite materials, J. Compos. Mater. 50 (2016) 1651–1659. doi:10.1177/0021998315595115. [15] L. Zhang, C. Ren, C. Zhou, H. Xu, X. Jin, Single fiber push-out characterization of interfacial mechanical properties in unidirectional CVI-C/SiC composites by the nano-indentation technique, Appl. Surf. Sci. 357 (2015) 1427–1433. doi:10.1016/j.apsusc.2015.10.018. [16] S. Zhandarov, E. Mäder, Characterization of fiber/matrix interface strength: Applicability of different tests, approaches and parameters, Compos. Sci. Technol. 65 (2005) 149–160. doi:10.1016/j.compscitech.2004.07.003. [17] S. Ghaffari, A. Makeev, G. Seon, D.P. Cole, D.J. Magagnosc, S. Bhowmick, Understanding compressive strength improvement of high modulus carbon-fiber reinforced polymeric composites through fiber-matrix interface characterization, Mater. Des. 193 (2020) 108798. doi:10.1016/j.matdes.2020.108798. [18] T. Xu, H. Luo, Z. Xu, Z. Hu, M. Minary-Jolandan, S. Roy, H. Lu, Evaluation of the Effect of Thermal Oxidation and Moisture on the Interfacial Shear Strength of Unidirectional IM7/BMI Composite by Fiber Push-in Nanoindentation, Exp. Mech. 58 (2018) 111–123. doi:10.1007/s11340-017-0335-6. [19] M. Rodríguez, J.M. Molina-Aldareguía, C. González, J. Llorca, A methodology to measure the interface shear strength by means of the fiber push-in test, Compos. Sci. Technol. 72 (2012) 1924–1932. doi:10.1016/j.compscitech.2012.08.011. [20] B. Miller, P. Muri, L. Rebenfeld, A microbond method for determination of the shear strength of a fiber/resin interface, Compos. Sci. Technol. 28 (1987) 17–32. doi:10.1016/0266-3538(87)90059-5. [21] X. Zhou, H.D. Wagner, S.R. Nutt, Interfacial properties of polymer composites measured by push-out and fragmentation tests, 32 (2001) 1543–1551. [22] N. Chandra, H. Ghonem, Interfacial mechanics of push-out tests: Theory and experiments, Compos. Part A Appl. Sci. Manuf. 32 (2001) 575–584. doi:10.1016/S1359-835X(00)00051-8. [23] K.N. Shivakumar, G. Swaminathan, M. Sharpe, Carbon/vinyl ester composites for enhanced performance in marine applications, J. Reinf. Plast. Compos. 25 (2006) 1101–1116. doi:10.1177/0731684406065194. [24] J. Summerscales, Durability of composites in the marine environment, 2014. doi:10.1007/978-94-007-7417-9_1. [25] K. Naito, C. Nagai, Effects of temperature and water absorption on the interfacial mechanical properties of carbon/glass-reinforced thermoplastic epoxy hybrid composite rods, Compos. Struct. 282 (2022) 115103. doi:10.1016/j.compstruct.2021.115103. [26] L.J. Ghosn, J.I. Eldridge, P. Kantzos, Analytical modeling of the interfacial stress state during pushout testing of SCS-6/Ti-Based composites, Acta Metall. Mater. 42 (1994) 3895–3908. doi:10.1016/0956-7151(94)90455-3. [27] M.N. Kallas, D.A. Koss, H.T. Hahn, J.R. Hellmann, Interfacial stress state present in a “thin-slice” fibre push-out test, J. Mater. Sci. 27 (1992) 3821–3826. doi:10.1007/BF00545464. [28] H. Chen, W. Hu, Y. Zhong, G. Gottstein, Finite element analysis of single-fiber push-out tests of continuous Al2O3 fiber-reinforced NiAl composites, Mater. Sci. Eng. A. 460–461 (2007) 624–632. doi:10.1016/j.msea.2007.01.087. [29] V.T. Bechel, N.R. Sottos, Application of debond length measurements to examine the mechanics of fiber pushout, J. Mech. Phys. Solids. 46 (1998) 1675–1697. doi:10.1016/S0022-5096(97)00040-9. [30] M.R. Wisnom, Size effects in the testing of ® bre-composite materials, Compos. Sci. Technol. 59 (1999) 1937–1957.

Conference: CAMX 2023

Publication Date: 2023/10/30

SKU: TP23-0000000167

Pages: 15

Price: $30.00

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