PSI - Issue 28

N. Selyutina et al. / Procedia Structural Integrity 28 (2020) 1310–1314 N. Selyutina / Structural Integrity Procedia 00 (2019) 000–000

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stress from 10 –3 s –1 to 1200 s –1 , in which carbon fiber layers are destroyed, is increased. The prediction of deformation dependencies with three stages of irreversible deformation in Fig. 1 and two stages in Fig. 2 using the relaxation model of plasticity agrees with experimental data. The reinforcement of the composite with layers of carbon fiber with a similar thickness to the aluminium layers result in no plastic deformation after the destruction of the fibrous layers of the composite (Fig. 2). A comparison of the composite deformations in Fig. 1 and Fig. 2 shows that the glass fiber metal composite exhibited a strong sensitivity to the strain rate and the presence of a stage of irreversible deformation after two stress drops. Thus, the relaxation model of plasticity is also applicable to layered materials subjected by quasi-static and dynamic loading. 5. Conclusions The research proves that the developed relaxation model of plasticity can predict the nonlinear deformation and associated material dependencies for fiber metal laminates. The stress drop effect related to the delamination of epoxy/fiber layers can also determined within the modified relaxation plasticity model. One major effect observed experimentally and theoretically is the basic dependency of the fiber metal laminate deformation on the strain rate. The relaxation model of plasticity demonstrated an ability to effectively predict the response of fiber metal laminates with different thicknesses of metal and fiber layers when subjected to both high strain rates and quasi-static loading. Acknowledgements The study was supported by the Russian Science Foundation, project no. 19-71-00093. References Karpov, E.V., Demeshkin, A.G., 2018. Strain and fracture of glass-fiber laminate containing metal layers. J. Appl. Mech. Tech. Physics, 59 (4), 699–705. Petrov, Y.V., 2007. On the Incubation Stage of Fracture and Structural Transformations in Continuous Media under Pulse Energy Injection. Mech. Solids 42(5), 692–699. Petrov, Y.V., Gruzdkov, A.A., Sitnikova, E.V., 2007. Anomalous Behavior of Yield Stress upon an Increase in Temperature under High Strain Rate Conditions. Dokl. Phys. 52(12), 691–694. Santiago, R. C., Alves, M., 2013. Dynamic characterization of a fiber-metal laminate. Key Eng. Mater., 535–536, 48–51. Selyutina, N., Borodin, E.N., Petrov, Y., Mayer A.E., 2016 The definition of characteristic times of plastic relaxation by dislocation slip and grain boundary sliding in copper and nickel. Int. J. Plast. 82, 97–111. Selyutina, N.S., Petrov, Yu.V., 2019. Modelling the time effects of irreversible deformation based on the relaxation model of plasticity. Phys. Solid State 61 (6), 935–940. Sharma, A.P., Khan, S.H., Parameswaran, V., 2019. Response and failure of fiber metal laminates subjected to high strain rate tensile loading. J. Compos. Mater. 53 (11), 1489–1506. Xia, Y., Wang, Y., Zhou, Y., Jeelani, S., 2007. Effect of strain rate on tensile behavior of carbon fiber reinforced aluminum laminates. Mater. Lett. 61, 213–215.