466
13 Experimental and Numerical Studies on Dynamic Behavior …
In summary, it is reasonable to use CONWEP method to predict the blast loadings
from the present one-end-detonated cylindrical charge with the scaled distances of
0.5 ~ 1.0 m/kg
1/3 .
13.5.2 Deflection-Time History
Figure 13.6 illustrates the comparisons between the experimental and numerical
simulated deflection curves, the rather good agreement can be derived, especially for
the maximum and residual deformations of panels. Therefore, the reliability of the
numerical model and the calibrated K&C parameters for UHPCC panels under blast
loadings are validated.
However, there are some deviations between the tested and simulated results. For
instance, the recorded maximum deflection of D 1 is larger than that of D 4 in the
test while there is slight difference between the two simulated results. The possible
reason may lie in that, compared with the FE model, the experimental panels were
not ideally supported with the one-way constrained condition. Besides, there is a
slight difference between the experimental deflection curves of D 2 and D 3 , which
are recorded from the two geometrically symmetric locations, while the simulated
results of the two locations are almost identical, which may be attributed to the
different overpressure distribution between the test and simulation. As mentioned
above, attributed to the different detonated points, the overpressure distributions on
panels are symmetric in the numerical model but asymmetric in the field test.
By comparing the deflection curves with various scaled distances, for both NSC
and UHPCC specimens, it is found that the precision of simulation results drops
as the scaled distance decreases, which is attributed to the reduction of precision
of CONWEP method on predicting the reflected overpressure with decreasing the
scaled distance. Comparably, for the small scaled distance, the numerical simulations
give a better predictions for the UHPCC specimens, since that NSC has relatively
low blast-resistance than UHPCC and the charge shape and point of detonation have
more obvious influences on NSC panels.
13.5.3 Post-blast Damage
Figure 13.16 shows the numerically predicted post-blast damage contour of the slabs.
By comparing with the test results shown in Fig. 13.9, it is concluded that the simulated post-blast damage of panels agrees well with the test results. However, the
deviations of damage distributions between the test and simulation also exist to some
extent, i.e. the simulation results show higher degree of damage. Three factors could
account for the above deviations: (i) the charge shape and point of detonation in the
numerical model differ from that in the field test; (ii) the heterogeneous concrete is
13 Experimental and Numerical Studies on Dynamic Behavior …
In summary, it is reasonable to use CONWEP method to predict the blast loadings
from the present one-end-detonated cylindrical charge with the scaled distances of
0.5 ~ 1.0 m/kg
1/3 .
13.5.2 Deflection-Time History
Figure 13.6 illustrates the comparisons between the experimental and numerical
simulated deflection curves, the rather good agreement can be derived, especially for
the maximum and residual deformations of panels. Therefore, the reliability of the
numerical model and the calibrated K&C parameters for UHPCC panels under blast
loadings are validated.
However, there are some deviations between the tested and simulated results. For
instance, the recorded maximum deflection of D 1 is larger than that of D 4 in the
test while there is slight difference between the two simulated results. The possible
reason may lie in that, compared with the FE model, the experimental panels were
not ideally supported with the one-way constrained condition. Besides, there is a
slight difference between the experimental deflection curves of D 2 and D 3 , which
are recorded from the two geometrically symmetric locations, while the simulated
results of the two locations are almost identical, which may be attributed to the
different overpressure distribution between the test and simulation. As mentioned
above, attributed to the different detonated points, the overpressure distributions on
panels are symmetric in the numerical model but asymmetric in the field test.
By comparing the deflection curves with various scaled distances, for both NSC
and UHPCC specimens, it is found that the precision of simulation results drops
as the scaled distance decreases, which is attributed to the reduction of precision
of CONWEP method on predicting the reflected overpressure with decreasing the
scaled distance. Comparably, for the small scaled distance, the numerical simulations
give a better predictions for the UHPCC specimens, since that NSC has relatively
low blast-resistance than UHPCC and the charge shape and point of detonation have
more obvious influences on NSC panels.
13.5.3 Post-blast Damage
Figure 13.16 shows the numerically predicted post-blast damage contour of the slabs.
By comparing with the test results shown in Fig. 13.9, it is concluded that the simulated post-blast damage of panels agrees well with the test results. However, the
deviations of damage distributions between the test and simulation also exist to some
extent, i.e. the simulation results show higher degree of damage. Three factors could
account for the above deviations: (i) the charge shape and point of detonation in the
numerical model differ from that in the field test; (ii) the heterogeneous concrete is