Issue 17

V. Crupi et alii, Frattura ed Integrità Strutturale, 17 (2011) 32-41; DOI: 10.3221/IGF-ESIS.17.04 41 The collapse of honeycomb sandwiches occurred for the buckling of the cells and is strongly influenced by the cell size, whereas the AFS collapsed for the foam crushing and their energy absorbing capacity depends by the foam quality, so the CT investigation is very useful to check their porosity distribution. For laminated composites, local contact stresses produced matrix cracks on the first impacted layer and the damage propagated through the thickness downward by a succession of intra-ply cracks and interface delaminations, producing the so called pine tree pattern. R EFERENCES [1] J. Baumeister, J. Banhart, M. Weber, Materials & Design, 18 (4) (1997) 217. [2] J. Banhart, C. Schmoll, U. Neumann, In: Proc. Conf. Materials in Oceanic Environment (Euromat ’98), Editor: L. Faria, 1 (1998) 55. [3] K.B. Shin, J.Y. Lee, S.H. Cho, Composite Structures, 84 (3) (2008) 228. [4] S. Abrate, Impact on Composite Structures, Edited by Cambridge University Press (2005). [5] L. Peroni, M. Avalle, M. Peroni, International Journal of Impact Engineering, 35 (2008) 644 [6] M.A. Hazizan, W.J. Cantwell, Composite: Part B, 34 (2003) 679. [7] P. Compston, M. Styles, S. Kalyanasundaram, Journal of Sandwich Structures and Materials, 8 (2006) 365. [8] V. Crupi, G. Epasto, E. Guglielmino, Journal of Sandwich Structures and Materials, (2011) doi:10.1177/1099636210385285. [9] O.B. Olurin, M. Arnold, C. Körner, R.F. Singer, Materials Science and Engineering, A328 (2002) 334. [10] M. Wicklein, K. Thoma, Materials Science and Engineering, A397 (2005) 391. [11] P.J. Schilling, B.R. Karedla, A.K. Tatiparthi, M.A. Verges, P.D. Herrington, Composites Science and Technology, 65 (2005) 2071. [12] K.T. Tan, N. Watanabe, Y. Iwahori, Composites: Part B, 42 (2011) 874. [13] S.R. Reid, G. Zhou, Impact behaviour of fibre-reinforced composite materials and structures, Edited by CRC Press, (2000). [14] G. Zhou, Composites Science and Technology, 54 (3) (1995) 267.