446
13 Experimental and Numerical Studies on Dynamic Behavior …
Table 13.4 Maximum and residual deflections of test specimens
Specimen Z
(m/kg 1/3 )
Maximum deflection (mm)
Residual deflection (mm)
D 1
D 2
D 3
D 4
D 1
D 2
D 3
D 4
Mid-span
NSC-1
1.0
32.96 20.16 18.80 26.66 /
8.60 5.38 /
11
NSC-2
0.8
43.48 23.95 21.41 33.59 15.51 8.83 4.94 15.79 /
NSC-3
0.6
/
35.34 33.53 59.50 /
22.44 21.37 44.32 /
UHPCC-1 0.8
27.86 17.17 17.94 21.90 5.94 2.91 3.25 5.89 /
UHPCC-2 0.6
58.94 30.25 28.71 49.63 37.15 19.28 18.36 38.33 /
UHPCC-3 0.5
/
28.97 27.4 /
/
11.69 11.48 /
28
intensive loadings, the maximum acceleration generally becomes larger when the
blast loadings are enhanced gradually, and the maximum accelerations even exceed
10,000 g in some scenarios. For example, as shown in Fig. 13.7b, c, the maximum
acceleration of NSC-2 is approximately 6000 g while that of NSC-3, i.e., panel
subjected to more intensive blast loading, is more than 10,000 g. When subjected
to the explosions with the same scaled distances, the vibration of UHPCC panels is
more obvious than that of NSC specimens due to the higher toughness and energy
absorbing capacity of UHPCC.
Besides, the FFT (Fast Fourier Transform) spectrums of partial specimens are
shown in Fig. 13.8. From Fig. 13.8a, c, it is concluded that the specimens with smaller
scaled distances oscillate with larger amplitude and higher frequency attributed to
more intensive blast loadings. Comparing the spectrums at different locations of
identical specimen, i.e., Figure 13.8d–f, it also can be found that the locations suffered
from more intensive blast loadings (the magnitude of blast loadings suffered by the
three acceleration sensors is sorted as follows: A1 > A2 > A3) oscillate with larger
amplitude and higher frequency. The comparison between Fig. 13.8b and d exhibits
that the UHPCC panel oscillates with higher frequency than NSC panel under same
scaled distance. This is due to the higher toughness of UHPCC panel compared to
the NSC panel. Moreover, UHPCC panels oscillate with larger amplitude since the
higher energy absorbing capacity of UHPCC.
13.3.3.4 Post-blast Damage
Figure 13.9 shows the post-blast damage of front, rear and side faces of test panels,
and the test specimens mainly exhibit the bending failure mode. Under the present
middle-range explosions, cracks firstly occur on the rear face of panels, and then
develop along the height direction of panels. The cracks were marked to be more
clear, and the solid lines represent the visible cracks while the dash lines represent the
tiny cracks. Generally, with the decrease of scaled distance, both NSC and UHPCC
panels suffered more serious damage, not only the total number of cracks but also the
13 Experimental and Numerical Studies on Dynamic Behavior …
Table 13.4 Maximum and residual deflections of test specimens
Specimen Z
(m/kg 1/3 )
Maximum deflection (mm)
Residual deflection (mm)
D 1
D 2
D 3
D 4
D 1
D 2
D 3
D 4
Mid-span
NSC-1
1.0
32.96 20.16 18.80 26.66 /
8.60 5.38 /
11
NSC-2
0.8
43.48 23.95 21.41 33.59 15.51 8.83 4.94 15.79 /
NSC-3
0.6
/
35.34 33.53 59.50 /
22.44 21.37 44.32 /
UHPCC-1 0.8
27.86 17.17 17.94 21.90 5.94 2.91 3.25 5.89 /
UHPCC-2 0.6
58.94 30.25 28.71 49.63 37.15 19.28 18.36 38.33 /
UHPCC-3 0.5
/
28.97 27.4 /
/
11.69 11.48 /
28
intensive loadings, the maximum acceleration generally becomes larger when the
blast loadings are enhanced gradually, and the maximum accelerations even exceed
10,000 g in some scenarios. For example, as shown in Fig. 13.7b, c, the maximum
acceleration of NSC-2 is approximately 6000 g while that of NSC-3, i.e., panel
subjected to more intensive blast loading, is more than 10,000 g. When subjected
to the explosions with the same scaled distances, the vibration of UHPCC panels is
more obvious than that of NSC specimens due to the higher toughness and energy
absorbing capacity of UHPCC.
Besides, the FFT (Fast Fourier Transform) spectrums of partial specimens are
shown in Fig. 13.8. From Fig. 13.8a, c, it is concluded that the specimens with smaller
scaled distances oscillate with larger amplitude and higher frequency attributed to
more intensive blast loadings. Comparing the spectrums at different locations of
identical specimen, i.e., Figure 13.8d–f, it also can be found that the locations suffered
from more intensive blast loadings (the magnitude of blast loadings suffered by the
three acceleration sensors is sorted as follows: A1 > A2 > A3) oscillate with larger
amplitude and higher frequency. The comparison between Fig. 13.8b and d exhibits
that the UHPCC panel oscillates with higher frequency than NSC panel under same
scaled distance. This is due to the higher toughness of UHPCC panel compared to
the NSC panel. Moreover, UHPCC panels oscillate with larger amplitude since the
higher energy absorbing capacity of UHPCC.
13.3.3.4 Post-blast Damage
Figure 13.9 shows the post-blast damage of front, rear and side faces of test panels,
and the test specimens mainly exhibit the bending failure mode. Under the present
middle-range explosions, cracks firstly occur on the rear face of panels, and then
develop along the height direction of panels. The cracks were marked to be more
clear, and the solid lines represent the visible cracks while the dash lines represent the
tiny cracks. Generally, with the decrease of scaled distance, both NSC and UHPCC
panels suffered more serious damage, not only the total number of cracks but also the