To study the effect of explosive charge defects on fast cook-off response characteristics, fast cook-off tests were conducted on type Ⅰ cook-off bomb (with defect-free charges) and type Ⅱ cook-off bomb (with defective charges). The results showed that the response time of type Ⅱ cook-off bomb (128 s) is shorter than that of type Ⅰ cook-off bomb (132 s), and the maximum shock wave overpressure at 5 m (62.7 kPa) is higher than that of type Ⅰ cook-off bomb (12.5 kPa). This indicates that the combustion of the type Ⅱ cook-off bomb was more intense than the defect-free type Ⅰ cook-off bomb after ignition, although both of them exhibit the same response level of burning reaction. Furthermore, a coupled computational model of pool fire and cook-off specimen was established to simulate the heating of the specimen in the flame using Fluent software. It is found that the closer the defect is to the charge surface, the higher local temperature at the defect, but it does not significantly affect the response time of explosive charges.

In order to investigate the damage mechanisms of zirconium-based amorphous alloy fragments penetrating carbon fiber targets and their subsequent effects on target failure, ballistic experiments were conducted using a 12.7 mm ballistic gun. The experiments involved spherical zirconium-based amorphous alloy fragments impacting a composite target system consisting of a 6-mm thick carbon fiber laminate and a 2-mm thick LY12 alloy plate. These targets were arranged in both stacked and spaced configurations to evaluate the effects of target configuration on the damage caused by fragment impact. To quantitatively assess the subsequent damage, image recognition technology was employed to analyze the damage area of the LY12 target after impact.The results indicated that the damage area of the carbon fiber target was positively correlated with the velocity of the impacting fragment, with no significant hole expansion observed. On the front side, damage primarily resulted from fiber shear failure and compressive deformation, while the back face of the carbon fiber laminate exhibited tensile tearing and interlaminar delamination. These findings suggest that the carbon fiber target experienced a combination of mechanical damage modes, including shear and compressive deformation on the impact side, and tensile and delamination failures on the rear face, as a result of the high-velocity impact.In the case of the LY12 aluminum alloy target, the damage area increased with fragment velocity. When the velocity was below 954.7 m/s, the damage area on the LY12 target in the spaced configuration was smaller than that of the stacked configuration. However, as the fragment velocity increased, the damage area of the LY12 target in the spaced configuration grew rapidly, while the damage area in the stacked configuration increased more gradually. At higher velocities, the damage area in the spaced configuration was significantly larger than that in the stacked configuration. This trend suggests that for high-velocity impacts, the spaced configuration of the targets was more effective in promoting greater damage to the LY12 target.