PSI - Issue 18

Roberta Massabò et al. / Procedia Structural Integrity 18 (2019) 484–489 Author name / Structural Integrity Procedia 00 (2019) 000–000

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4. Conclusions A multiscale homogenized model has been formulated to analyze mode II dominant multiple delamination fracture in layered composite and sandwich beams. The model enriches the displacement field of a first order shear deformation theory to account for zig-zag effects and the presence of delaminations and homogenized equations are derived which depend on the global variables only. The through thickness discretization is therefore unnecessary in the solution of fracture problems. The model captures the unstable propagation of cracks, snap-back and snap-through instabilities, the effects of the interaction of multiple cracks on the macrostructural response and of the layered structure on the energy release rate. Acknowledgements Support by the U.S. Navy, Office of Naval Research, grant N00014-17-1-2914, and by the Italian Department for University and Scientific and Technological Research, MIUR Prin15 project 2015LYYXA8. References Andrews, M.G., Massabò, R., and Cox, B.N., 2006, Elastic interaction of multiple delaminations in plates subject to cylindrical bending, Int. J. Solids Struct. 43(5):855–886, doi:10.1016/j.ijsolstr.2005.04.025. Andrews, M.G. and Massabò, R., 2008, Delamination in flat sheet geometries with material imperfections and thickness variations, Compos. Part B Eng. 39(1):139–150, doi:10.1016/j.compositesb.2007.02.017. Barbieri L, Massabò R, Berggreen C., 2018, The effects of shear and near tip deformations on interface fracture of symmetric sandwich beams. Eng Fract Mech;201:298–321. doi:10.1016/j.engfracmech.2018.06.039. Darban, H., Massabò, R., 2018, A homogenized structural model for shear deformable composites with compliant interlayers, Multiscale Multidiscip. Model. Exp. Des. 1:269–290, doi:10.1007/s41939-018-0032-x. Di Sciuva, M., 1986, Bending, vibration and buckling of simply supported thick multilayered orthotropic plates: An evaluation of a new displacement model, J. Sound Vib., doi:10.1016/0022-460X(86)90169-0. Eijo, A., Oñate, E., and Oller, S., 2013, A numerical model of delamination in composite laminated beams using the LRZ beam element based on the refined zigzag theory, Compos. Struct., doi:10.1016/j.compstruct.2013.04.035. Flores, F.G., Oller, S., and Nallim, L.G., 2018, On the analysis of non-homogeneous laminates using the refined zigzag theory, Compos. Struct., doi:10.1016/j.compstruct.2018.08.018. Li S, Wang J, Thouless MD. 2004, The effects of shear on delamination in layered materials. J Mech Phys Solids;52:193–214. Lundsgaard-Larsen, C., Massabò, R. and Cox, B.N., (2012), On acquiring data for large-scale crack bridging at high strain rates, Journal of Composite Materials, 46(8), 949-971, 2012, DOI: 10.1177/ 0021998311413622jcm.sagepub.com. Madhukar, M.S. and Drzal, L.T., 1992, Fiber-Matrix Adhesion and Its Effect on Composite Mechanical Properties: IV. Mode I and Mode II Fracture Toughness of Graphite/Epoxy Composites, J. Compos. Mater. 26(7):936–968, doi:10.1177/002199839202600701. Massabò, R. and Campi, F., 2014, An efficient approach for multilayered beams and wide plates with imperfect interfaces and delaminations, Compos. Struct. 116(1):311–324, doi:10.1016/j.compstruct.2014.04.009. Massabò, R. and Campi, F., 2015, Assessment and correction of theories for multilayered plates with imperfect interfaces, Meccanica 50(4):1045– 1071, doi:10.1007/s11012-014-9994-x. Massabo, R; Darban, H., 2019, Mode II dominant fracture of layered composite beams and wide-plates: a homogenized structural approach, Eng. Fract. Mech., doi:10.1016/j.engfracmech.2019.03.002. Massabò R. 2014, Influence of boundary conditions on the response of multilayered plates with cohesive interfaces and delaminations using a homogenized approach. Frattura ed Integrita Strutturale;8. doi:10.3221/IGF-ESIS.29.20. Pelassa M, Massabò R., 2015, Explicit solutions for multi-layered wide plates and beams with perfect and imperfect bonding and delaminations under thermo-mechanical loading. Meccanica;50:2497–524. doi:10.1007/s11012-015-0147-7. Tessler A, Di Sciuva M, Gherlone M., 2009, A refined zigzag beam theory for composite and sandwich beams. J. Compos. Mater., doi:10.1177/0021998308097730