Research On Damage Characteristics And Rules Of Bridge-wire Electric Detonator Under High Acceleration Loading

As energetic device in the ammunition system, explosive initiator happens accident easily under the environment of bullet impacting or penetrating target. In order to reduce the unexpected incidence, the paper is to perform the damage characteristics and damage mechanism of both the one-leg and two-legs bridge-wire detonators typically used in fuse by the air gun experiment.(1) Structural damage were surveyed. When loaded by axial mode, due to the inertial effect, one-leg the detonator showed a relative displacement of components, causing the invagination of electrode and electrode plug, and the length of detonator decreased, the extent of which increased with acceleration increasing, and the change rate was in the range of1～3.5%. The diameter around the output of the detonator was enlarged, and the diameter enlarged more with the acceleration increasing. When loaded by lateral loading mode, the acceleration peak was higher, the electrode deviated more from central axis. And the bridge wire was broken easily. When loaded by the axial mode, the length of the two-legs decreased less than2%, and the extent decreased more with the acceleration increasing. However, the length of detonators decreased with the acceleration increasing when loaded by lateral mode, but the extent were less than1%.(2) Resistance changed unobviously under air gun experiment. The change ratios of resistance value were less than7%when one-leg detonators were loaded by the method of output loading, and resistance change ratios of individual samples changed obviously up to247%as lateral loading was adopted. In addition, when two-legs detonators were loaded, the resistance value increased with the acceleration peak increased under output loading, but resistance were unchanged under lateral loading.(3) The output power changed. The distributions of output power of the one-leg detonator are2.00～2.18mm and1.95-2.27mm before and after being loaded respectively. As well, The distributions of output power of the two-legs detonator are1.19～1.47mm and1.37～1.42mm before and after being loaded respectively. Both the results showed the loading process had no effect on the output power of detonator.(4) Results from simulation and air gun experiment showed that the bullet was subjected strong inertial effect and the stress wave transmitted in the sample repeatedly in the form of compression and tension wave, which caused the damage phenomena of the detonator, with the characteristic of size, resistance, internal stress and output power. Results from the simulation is well agreement with that from the experiment.