5.1 Comparison between FEM simulation results and laboratory test results without considering the microstructure of the target

(cross-section images) were stacked together and processed to generate their respective digital specimen. Elements pertaining to different components of the mixture (i.e., aggregates and cement paste) were assigned different material properties in the simulation. The aggregates were treated as elastic material with high elastic stiffness, whereas the cement paste was treated as an elasto-plastic material with low elastic stiffness and shear damage factor to control the damage

The effect of the projectile mass on the penetration was assessed by considering three different masses in the simulation – 0.2, 0.4, and 0.6 kg, respectively. Other properties of the projectiles were kept the same. The simulation data are presented in Figure 14. From the figure it can be noticed that the projectile penetration depth increases as its mass increases (a) whereas the penetration speed decreases at

5.3 Effect of projectile mass on the simulated penetration

smaller rates for larger mass projectiles (b).

Internal structure reconstruction of the concrete specimen.

Concrete Microstructure Characterization and Performance

DOI: http://dx.doi.org/10.5772/intechopen.90500

of the material.

43

Figure 13.

It is worth mentioning that both the mass and diameter of the projectiles influence the penetration depths. However, the major factor to determine the penetration depth is the velocity of the projectile. For example, in tests 7 and 8, the two projectiles have similar masses and diameters, but the projectile with higher velocity (405 m/s) has a penetration depth of 51 mm which is almost twice the depth of the one with lower velocity (360.5 m/s). This fact is also revealed by the simulation results, pertaining to the same tests, in which the projectile having a higher velocity has a 106 mm penetration depth, while the one with lower velocity has a 51 mm penetration depth. The major reason for the inconsistency between the simulation results and the test results is that the material properties including microstructure were not varied for different materials (Table 3).


Table 3.

Penetration depth comparison between test data and simulation (Zhou et al., 2009).
