PSI - Issue 13

4

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

2123

� � ∑ ∆ � � � ⁄ and � � � � � � ∗ �� ∗ � � �

(4)

where � and � are constants and ∗ and ∗ are defined earlier in equation (1). In all the simulations the spherical projectile is modeled as an elastic material with an elastic modulus of 210 GPa and a Poisson’s ratio of 0.29. After EOI test validation on monolithic glass plates, the influence of PU interlayer was studied to reduce the wave speed. The PU interlayer of various thicknesses (0.5 mm, 1.0 mm, 2.0 mm, and 3.0 mm) was modeled using linear EOS, and principal stress failure criterion. The main mechanical properties of the projectile, soda-lime glass, and PU interlayer are listed in table 1.

Table 1 The main mechanical properties of the materials used.

Density (kg/m 3 )

Elastic modulus (GPa)

Poisson’s ratio (--)

Shear modulus (GPa)

Part

Material

Projectile

Steel 4340

7830 2500 1265

210.0

0.29 0.21

81.8

Target

Soda-lime glass

73.0

29.67 0.005

Interlayer

PU

0.015

0.498

4. Results and discussion In the previous section of the current paper, the FE and materials model detail to simulate the EOI impact tests on monolithic and laminated glass plates impacted by the spherical projectile is explained. Here, we will present and discuss the calculated results for EOI simulations on glass and glass laminates. In the first phase of the study, the normal EOI simulation results on a glass plate are compared for the velocity of 440 m/s with the experimental results of Strassburger et al. [8]. The figure 3 (a & b) shows the comparison of the longitudinal and transverse wave propagation after 7.7 µs of impact. It can be seen that both computed and experimental results are in close agreement with each other in terms of wave arrival time and position. The comparison of the damage zone is also shown in figure 3 (c). This also verifies our numerical set-up and a material parameter of the JH-2 model used in simulations.

Figure 3 Comparison of the calculated longitudinal wavefront (a), transversal wavefront (b), and damage zone after 7.7 µs with experiment [8]