Fatih BALIKOĞLU, Tayfur Kerem DEMİRCİOĞLU

Geometrik Olarak Asimetrik Kompozit Sandviç Kirişlerin Eğilme Yükü Altındaki Davranışı Üzerine Deneysel ve Teorik Çalışma

Bu çalışma, polivinil klorür (PVC) köpük çekirdek ve E-cam elyaf takviyeli polimer tabakalardan oluşan asimetrik sandviç kirişlerin üç nokta ve dört nokta eğilme davranışları hakkında ayrıntılı bir araştırma sunmaktadır. Sandviç kirişlerin eğilme yükü-sehim davranışı ve hasar mekanizması üzerindeki orta düzlem asimetrisinin etkileri incelenmiştir. Sandviç kirişlerin eğilme ve kayma rijitlik değerlerini hesaba katan basit analitik ifadeler, numunelerin hasar yükünü, kiriş orta-nokta sehmini ve eşdeğer eğilme rijitliğini tahmin etmek için önerilmiş ve deneysel sonuçlar ile doğrulanmıştır. Yükleme yönünü değiştirerek, asimetrik kirişlerin eğilme davranışı kontrol edilebilir. Yükleme tarafında, kalın veya yüksek düzlem içi mekanik özelliklere sahip yüzey tabakasının kullanılması, üst yüzey tabakasında basma hasarı gecikmesine neden olmuştur. Uygulanan formül kayma deformasyonlarını hesaba katmadığı için etkin eğilme rijitliği değerleri yüksek tahmin edilmiştir. Birinci mertebe kayma deformasyon teorisi, elastik bölgede sandviç kirişlerin orta açıklık deplasman değerlerinin tahmin etmek için kullanılmış ve deneysel sonuçlarla iyi bir uyum göstermiştir.

Anahtar Kelimeler:

Asimetrik sandviç kirişler, Eğilme özellikleri, PVC köpük

Experimental and Theoretical Study on Behaviour of Geometrically Asymmetric Composite Marine Sandwich Beams under Bending Load

This study presents a detailed investigation on the three-point and four-point bending behaviour of asymmetric sandwich beams composed of polyvinyl chloride (PVC) foam core and E-glass fibre reinforced polymer face sheets. The effects of mid-plane asymmetry on the bending load-displacement behaviour and failure mechanism of the sandwich beams were examined. Simple analytical expressions accounting for flexural and shear rigidities of the sandwich beams were proposed to predict the failure load, mid-span deflection and equivalent bending stiffness of the specimens and validated against experimental results. By shifting the loading direction, the flexural behaviour of asymmetric beams may be controlled. On the loading side, the use of face sheet with thick or high in-plane mechanical characteristics resulted in a delay in compressive failure of the top face sheet. The effective bending stiffness was overestimated since the applied formula did not account for shear deformations. First-order shear deformation theory was used to estimate the mid-span displacement values of sandwich beams in elastic regime and showed good agreement with the experimental results.

Keywords:

Asymmetric sandwich beams, Flexural properties, PVC foam,

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[1] Zenkert, D., “Chapter 3: Fundamentals” in An Introduction to Sandwich Structures, Chamelon, Oxford, 1995, pp. 3.1-3.12.
[2] A. Mouritz and R. Thomson, "Compression, flexure and shear properties of a sandwich composite containing defects," Composite structures, vol. 44, no. 4, pp. 263-278, 1999.
[3] L. Calabrese, G. Di Bella, and V. Fiore, "Manufacture of marine composite sandwich structures," in Marine Applications of Advanced Fibre-Reinforced Composites: Elsevier, 2016, pp. 57-78.
[4] D. Zenkert, "Damage tolerance of naval sandwich panels," in Major Accomplishments in Composite Materials and Sandwich Structures: Springer, 2009, pp. 279-303.
[5] L. Sutherland, "A review of impact testing on marine composite materials: Part III-Damage tolerance and durability," Composite structures, vol. 188, pp. 512-518, 2018.
[6] A. Mouritz, E. Gellert, P. Burchill, and K. Challis, "Review of advanced composite structures for naval ships and submarines," Composite structures, vol. 53, no. 1, pp. 21-42, 2001.
[7] E. Greene. (2020, May 27). "Lecture Notes." Eric Greene Associates, Inc. [Online]. Available:http://ericgreeneassociates.com/webbinstitute.html.
[8] G. Di Bella, C. Borsellino, and L. Calabrese, "Effects of manufacturing procedure on unsymmetrical sandwich structures under static load conditions," Materials & Design, vol. 35, pp. 457-466, 2012.
[9] J. Dai and H. T. Hahn, "Flexural behavior of sandwich beams fabricated by vacuum-assisted resin transfer molding," Composite Structures, vol. 61, no. 3, pp. 247-253, 2003.
[10] T. Sharaf, W. Shawkat, and A. Fam, "Structural performance of sandwich wall panels with different foam core densities in one-way bending," Journal of Composite Materials, vol. 44, no. 19, pp. 2249-2263, 2010.
[11] R. Umer, E. Waggy, M. Haq, and A. Loos, "Experimental and numerical characterizations of flexural behavior of VARTM-infused composite sandwich structures," Journal of Reinforced Plastics and Composites, vol. 31, no. 2, pp. 67-76, 2012.
[12] A. Mostafa, K. Shankar, and E. Morozov, "Experimental, theoretical and numerical investigation of the flexural behaviour of the composite sandwich panels with PVC foam core," Applied Composite Materials, vol. 21, no. 4, pp. 661-675, 2014.
[13] A. Mostafa, K. Shankar, and E. Morozov, "Behaviour of PU-foam/glass-fibre composite sandwich panels under flexural static load," Materials and Structures, vol. 48, no. 5, pp. 1545-1559, 2015.
[14] H. Mathieson and A. Fam, "In-plane bending and failure mechanism of sandwich beams with GFRP skins and soft polyurethane foam core," Journal of Composites for Construction, vol. 20, no. 1, pp. 04015020, 2015.
[15] W. Ferdous, A. Manalo, and T. Aravinthan, "Effect of beam orientation on the static behaviour of phenolic core sandwich composites with different shear span-to-depth ratios," Composite Structures, vol. 168, pp. 292-304, 2017.
[16] S. V. Iyer, R. Chatterjee, M. Ramya, E. Suresh, and K. Padmanabhan, "A Comparative study of the three point and four point bending behaviour of rigid foam core glass/epoxy face sheet sandwich composites," Materials Today: Proceeding, vol. 5, no. 5, pp. 12083-12090, 2018.
[17] W. Ferdous, A. Manalo, T. Aravinthan, and A. Fam, "Flexural and shear behaviour of layered sandwich beams," Construction and Building Materials, vol. 173, pp. 429-442, 2018.
[18] C. Kaboglu, L. Yu, I. Mohagheghian, B. R. Blackman, A. J. Kinloch, and J. P. Dear, "Effects of the core density on the quasi-static flexural and ballistic performance of fibre-composite skin/foam-core sandwich structures," Journal of Materials Science, vol. 53, no. 24, pp. 16393-16414, 2018.
[19] F. Balıkoğlu, N. Arslan, T. Demircioğlu, O. İnal, M. Iren, and A. Ataş, "Improving four-point bending performance of marine composite sandwich beams by core modification," Journal of Composite Materials, vol. 54, no. 8, pp. 1049-1066, 2020.
[20] F. Zhang, J. Xu, B. Esther, H. Lu, H. Fang, and W. Liu, "Effect of shear span-to-depth ratio on the mechanical behavior of composite sandwich beams with GFRP ribs and balsa wood core materials," Thin-Walled Structures, vol. 154, p. 106799, 2020.
[21] Y. Gupta, A. Jacob, and A. Mohanty, "Effect of the core thickness on the flexural behaviour of polymer foam sandwich structures," IOP SciNotes, vol. 1, no. 2, p. 024404, 2020.
[22] Ł. Pyrzowski and B. Sobczyk, "Local and global response of sandwich beams made of GFRP facings and PET foam core in three point bending test," Composite Structures, vol. 241, p. 112-122, 2020.
[23] M. Kazemi, "Experimental analysis of sandwich composite beams under three-point bending with an emphasis on the layering effects of foam core," Structures, vol. 29: Elsevier, pp. 383-391, 2021.
[24] A. Giordano, L. Mao, and F.-P. Chiang, "Full-field experimental analysis of a sandwich beam under bending and comparison with theories," Composite Structures, vol. 255, p. 112965, 2021.
[25] W. Liu, F. Zhang, L. Wang, Y. Qi, D. Zhou, and B. Su, "Flexural performance of sandwich beams with lattice ribs and a functionally multilayered foam core," Composite Structures, vol. 152, pp. 704-711, 2016.
[26] Y. Frostig, M. Baruch, O. Vilnay, and I. Sheinman, "Bending of nonsymmetric sandwich beams with transversely flexible core," Journal of Engineering Mechanics, vol. 117, no. 9, pp. 1931-1952, 1991.
[27] N. R. Satapathy and J. R. Vinson, "Sandwich Beams With Mid-Plane Asymmetry Subjected To Lateral Loads Analysis And Optimization," Master of Mechanical Engineering Thesis, Univerisity of Delaware, 1999.
[28] N. R. Satapathy and J. R. Vinson, "Sandwich beams with mid-plane asymmetry subjected to lateral loads," Journal of Sandwich Structures & Materials, vol. 2, no. 4, pp. 379-390, 2000.
[29] B. Castanié, J.-J. Barrau, and J.-P. Jaouen, "Theoretical and experimental analysis of asymmetric sandwich structures," Composite Structures, vol. 55, no. 3, pp. 295-306, 2002.
[30] G. Di Bella, L. Calabrese, and C. Borsellino, "Mechanical characterisation of a glass/polyester sandwich structure for marine applications," Materials & Design, vol. 42, pp. 486-494, 2012.
[31] J. Zhang, Q. Qin, W. Ai, H. Li, and T. Wang, "The failure behavior of geometrically asymmetric metal foam core sandwich beams under three-point bending," Journal of Applied Mechanics, vol. 81, no. 7, 2014.
[32] M. E. Toygar, K. F. Tee, F. K. Maleki, and A. C. Balaban, "Experimental, analytical and numerical study of mechanical properties and fracture energy for composite sandwich beams," Journal of Sandwich Structures & Materials, vol. 21, no. 3, pp. 1167-1189, 2019.
[33] F. Balıkoğlu, T. K. Demircioğlu, M. Yıldız, N. Arslan, and A. Ataş, "Mechanical performance of marine sandwich composites subjected to flatwise compression and flexural loading: Effect of resin pins," Journal of Sandwich Structures & Materials, vol. 22, no. 6, pp. 2030-2048, 2020.
[34] B. Castanié, J.-J. Barrau, J.-P. Jaouen, and S. Rivallant, "Combined shear/compression structural testing of asymmetric sandwich structures," Experimental Mechanics, vol. 44, no. 5, pp. 461-472, 2004.
[35] J. Deng, A. Peng, W. Chen, G. Zhou, and X. Wang, "On stability and damage behavior of asymmetric sandwich panels under uniaxial compression," Journal of Sandwich Structures & Materials, vol. 23, no. 6, pp. 1870-1901, 2021.
[36] W. Zhang, Q. Qin, J. Li, B. Su, and J. Zhang, "A comparison of structural collapse of fully clamped and simply supported hybrid composite sandwich beams with geometrically asymmetric face sheets," Composites Part B: Engineering, vol. 201, p. 108398, 2020.
[37] Core Materials. (2021, October 2). Datasheet for Airex C70 PVC Foam [Online]. Available: https://www.3accorematerials.com/en/markets-and-products/airex-foam/airex-c70-pvc-foam.
[38] E. ISO, "527–4. Determination of tensile properties–Part 4: test conditions for isotropic and orthotropic fibre-reinforced plastic composites. European Standard," International Organization for Standardization, 1997.
[39] ASTM Standard Test Method for Compressive Properties of Polymer Matrix Composite Materials Using a Combined Loading Compression (CLC) Test Fixture, ASTM D6641 / D6641M, ASTM, West Conshohocken, PA, 2016.
[40] ASTM Standard Test Method for Shear Properties of Composite Materials by V-Notched Rail Shear Method, ASTM D7078 / D7078M, ASTM, West Conshohocken, PA, Pennsylvania, USA, 2012.
[41] Poliya. (2021, December 29). Data sheet for cured Polives 702 Bisphenol-A epoxy Vinylester Resin. [Online]. Available: https://www.poliya.com/tr/bisfenol-a-epoksi-bazli-vinilester-recineler.
[42] K.-T. Hsiao and D. Heider, "Vacuum assisted resin transfer molding (VARTM) in polymer matrix composites," in Manufacturing techniques for polymer matrix composites (PMCs): Elsevier, 2012, pp. 310-347.
[43] ASTM Standard Test Method for Core Shear Properties of Sandwich Constructions by Beam Flexure, ASTM C393 / C393M-16, ASTM, West Conshohocken, PA, 2016.
[44] C. A. Steeves and N. A. Fleck, "Collapse mechanisms of sandwich beams with composite faces and a foam core, loaded in three-point bending. Part I: analytical models and minimum weight design," International Journal of Mechanical Sciences, vol. 46, no. 4, pp. 561-583, 2004.
[45] I. M. Daniel, E. E. Gdoutos, J. L. Abot, and K.-A. Wang, "Deformation and failure of composite sandwich structures," Journal of Thermoplastic Composite Materials, vol. 16, no. 4, pp. 345-364, 2003.
[46] A. Manalo, T. Aravinthan, W. Karunasena, and M. Islam, "Flexural behaviour of structural fibre composite sandwich beams in flatwise and edgewise positions," Composite Structures, vol. 92, no. 4, pp. 984-995, 2010.
[47] A. Manalo, "Behaviour of fibre composite sandwich structures under short and asymmetrical beam shear tests," Composite Structures, vol. 99, pp. 339-349, 2013.
[48] Y. Qi, H. Fang, H. Shi, W. Liu, Y. Qi, and Y. Bai, "Bending performance of GFRP-wood sandwich beams with lattice-web reinforcement in flatwise and sidewise directions," Construction and Building Materials, vol. 156, pp. 532-545, 2017.
[49] P. Sadeghian, D. Hristozov, and L. Wroblewski, "Experimental and analytical behavior of sandwich composite beams: Comparison of natural and synthetic materials," Journal of Sandwich Structures & Materials, vol. 20, no. 3, pp. 287-307, 2018.