PSI - Issue 13

Muhammad Zakir Sheikh et al. / Procedia Structural Integrity 13 (2018) 2120–2125 Muhammad Zakir Sheikh et al. / Structural Integrity Procedia 00 (2018) 000–000

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to design lightweight transparent armor and transparencies. In the design of the transparent laminate structure, the order of glass or glass-ceramic layer, the selection of interlayer material and layer thickness play a very important role [4, 6, 7]. The major contribution in the development of optimized transparent layered structure requires extensive testing, in this regard the most famous work of Strassburger et al. [8] utilizing edge-on-impact testing technique provided wave propagation, deformation mechanism and damage propagation in a variety of transparent materials and laminates. This kind of testing requires special instruments like ultra-high-speed cameras, special lens, light source and stress wave visualization system, which is a time-consuming and costly process. Therefore, the numerical simulations are the most efficient way of designing the laminated structures and more in-depth details of the failure process, crack initiation and damage propagation in glass and laminate layers can be studied. With the advancement in numerical techniques and development of John-Holmquist (JH-2) material model [9] in a variety of commercially available software like ANSYS/Autodyn, ANSYS/Ls-Dyna and ABAQUS/Explicit it is possible to accurately simulate the behavior of brittle materials like glass to high-speed projectile impact. M. Grujicic et al. [10, 11] proposed a continuum damage based material model to precisely envisage the propagation of longitudinal and transverse waves, coherent damage zones and localized damage zone ahead of the coherent zone for Starphire glass. In this work, first the numerical simulations on of spherical projectile impact on soda-lime glass are conducted using ANSYS/Autodyn and calculated results for wave propagation are compared with the edge-on-impact tests on soda-lime glass performed by Strassburger et al. [8]. The JH-2 material model is used to model the glass plate of size 100 × 100 × 10 mm3 impacted by Steel 4340 spherical-shaped projectile of diameter 16 mm at an impact velocity of 440 m/s. Both target plate and projectile are discretized using solid elements and Lagrange/Lagrange interaction logic is used for contact. modeled using to study the static and dynamic compression behavior of un-strengthened ALS glass is studied experimentally. In windshield or armor design laminated transparent structure is used so, EOI numerical study was extended to see the influence of PU interlayer in minimizing the stress wave and damage area in the glass structure. The PU was modeled using linear equation-of-state (EOS) and principle stress failure criterion. Also, the addition of two PU layers and plus-shaped (one axial and one vertical) polymeric layer is introduced to bifurcate the wave propagation and damage region to high-speed spherical projectile impact. The delay time in wave arrival time as a function of interlayer thickness was estimated. The more detailed discussion about the simulation work is provided in upcoming sections of this paper. 2. EOI Experimental Scheme The schematic of the EOI test on transparent monolithic and laminated materials conducted by Strassburger et al. [8] is shown in figure 1.

Figure 1 A schematic of edge-on-impact test set-up (a) crossed polarizers technique, (b) shadowgraphs.