International Science Index


An Investigation on the Sandwich Panels with Flexible and Toughened Adhesives under Flexural Loading


The material selection in the design of the sandwich structures is very crucial aspect because of the positive or negative influences of the base materials to the mechanical properties of the entire panel. In the literature, it was presented that the selection of the skin and core materials plays very important role on the behavior of the sandwich. Beside this, the use of the correct adhesive can make the whole structure to show better mechanical results and behavior. In the present work, the static three-point bending tests were performed on the sandwiches having an aluminum alloy foam core, the skins made of three different types of fabrics and two different commercial adhesives (flexible polyurethane and toughened epoxy based) at different values of support span distances by aiming the analyses of their flexural performance in terms of absorbed energy, peak force values and collapse mechanisms. The main results of the flexural loading are: force-displacement curves obtained after the bending tests, peak force and absorbed energy values, collapse mechanisms and adhesion quality. The experimental results presented that the sandwiches with epoxy based toughened adhesive and the skins made of S-Glass Woven fabrics indicated the best adhesion quality and mechanical properties. The sandwiches with toughened adhesive exhibited higher peak force and energy absorption values compared to the sandwiches with flexible adhesive. The use of these sandwich structures can lead to a weight reduction of the transport vehicles, providing an adequate structural strength under operating conditions.

[1] W. J. Cantwell, G. R. Villanueva, “The high velocity impact response of composite and FML-reinforced sandwich structures”, Composite Science and Technology, vol. 64, pp. 35-54, 2004.
[2] J. Banhart, “Manufacture, characterisation and application of cellular metals and metal foams”, Progress in Material Science, vol. 46, no. 6, pp. 559–632, 2001.
[3] H. P. Degischer, B. Kriszt, Handbook of cellular metals: production, processing, applications. Weinheim: Wiley-VCH Verlag, 2002, ch. 4.
[4] V. Crupi, G. Epasto, E. Guglielmino, “Comparison of aluminium sandwiches for lightweight ship structures: honeycomb vs. foam”, Marine Structures, vol. 30, pp. 74 – 96, 2013.
[5] E. Kara, V. Crupi, G. Epasto, E. Guglielmino, H. Aykul, “Low velocity impact response of glass fiber reinforced aluminium foam sandwich”, in Proc. of 15th European Conference on Composite Materials (ECCM15), Venice, 2012, pp. 1-8.
[6] G. Reyes, “Mechanical behavior of thermoplastic FML-reinforced sandwich panels using an aluminum foam core: experiments and modelling”, Journal of Sandwich Structures and Materials, vol. 12, pp. 81 – 96, 2010.
[7] J. Banhart, C. Schmoll, U. Neumann, “Light-weight aluminium foam structures for ships”, in Proc. Conf. Materials in Oceanic Environment (Euromat ’98), Lisbon, 1998, vol. 1, pp. 55–63.
[8] L. J. Gibson, M. F. Ashby, Cellular solids: structure and properties. Oxford: Pergamon Press, 1997.
[9] M. F. Ashby, A. G. Evans, N. A. Fleck, L. J. Gibson, J. W. Hutchinson, H. N. G. Wadley, Metal foams: a design guide. Boston: Butterworth- Heinemann, 2000.
[10] T. M. McCormack, R. Miller, O. Kesler, L. J. Gibson, “Failure of sandwich beams with metallic foam cores”, International Journal of Solids and Structures, vol. 38, pp. 4901–4920, 2001.
[11] H. Bart-Smith, J. Hutchinson, A. Evans, “Measurement and analysis of the structural performance of cellular metal sandwich construction”, International Journal of Mechanical Sciences, vol. 43, no. 8, pp. 1945– 1963, 2001.
[12] J. Yu, E. Wang, J. Li, Z. Zheng, “Static and low-velocity impact behaviour of sandwich beams with closed-cell aluminum foam core in three-point bending”, International Journal of Impact Engineering, vol. 35 , no. 8, pp. 885–894, 2008.
[13] K. Mohan, Y. T. Hon, S. Idapalapati, H. P. Seow, “Failure of sandwich beams consisting of alumina face and aluminum foam core in bending”, Materials Science and Engineering:A, vol. 409, pp. 292–301, 2005.
[14] C. Chen, A. M. Harte, N. A. Fleck, “The plastic collapse of sandwich beams with a metallic foam core”, International Journal of Mechanical Sciences, vol. 43, no. 6, pp. 1483–1506, 2001.
[15] Y. Shenhar, Y. Frostig, E. Altus, “Stresses and failure patters in the bending of sandwich beams with transversely flexible cores and laminated composite skins”, Composite Structures, vol. 35, pp. 143–152, 1996.
[16] M. Kampner, J. L. Grenestedt, “On using corrugated skins to carry shear in sandwich beams”, Composite Structures, vol. 85, pp. 139–148, 2007.
[17] V. L. Tagarielli, N. A. Fleck, V. S. Deshpand, “The collapse response of sandwich beams with aluminium face sheets and a metal foam core in three-point bending”, in Proceedings of cellular metals and metal foaming technology (MetFoam2003), Berlin, 2003, pp. 381–386.
[18] H. Bart-Smith, J. W. Hutchinson, N. A. Fleck, A. G. Evans, “Influence of imperfections on the performance of metal foam core sandwich panels”, International Journal of Solids and Structures, vol. 39, pp. 4999–5012, 2002.
[19] O. Kesler, L. J. Gibson, “Size effects in metallic foam core sandwich beams”, Materials Science and Engineering:A, vol. 326, no. 2, pp. 228– 234, 2002.
[20] C. A. Steeves, N. A. Fleck, “Collapse mechanism 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, pp. 561–583, 2004.
[21] V. Crupi, R. Montanini, “Aluminium foam sandwiches collapse modes under static and dynamic three-point bending”, International Journal of Impact Engineering, vol. 34, pp. 509 – 521, 2007.
[22] J. Baumeister, J. Banhart, M. Weber, “Aluminium foams for transport industry”, Materials & Design, vol. 18, pp. 217-220, 1997.