Detonation of plane charges of mixed explosives in application to welding by explosion

Abstract

The detonation velocity was measured by the method of contact sensors [5] by using ChZ34 frequency meters successively at three bases in each charge. To raise the reliability of the mean values of D for each mixture and HE with definite thickness H the measurements were performed on five charges. The HE were shaped by using wood casings on a rigid foundation (steel plates 5 mm thick). The contact sensors [5] fabricated from two twisted copper wires of 0.22 mm diameter (one without insulation, while the other had a lacquer coating) were glued to the plate under the HE charge through a thin insulating interlayer. Compact twisting of the wires assured the needed sensor sensitivity to the action of the shockwave in the HE. Measurement error did not exceed 2%. In certain cases when D = 1500-2200 m/sec was expected, a rheostat method was used in parallel with the method described [12]. Moreover, contact sensors from 0.04 mm thick copper foil were used for D ~ 1500 m/sec (two narrow 2  i0 mm strips separated by a gap of 0.2-0.3 mm). The foil sensors were placed alongside the wire. The values of D obtained by all three methods for identical charges differed by not more than 3%. Therefore, the selection of the methodology based on using contact sensors in the form of twisted wires is fully justified. The component content for all the mixtures in Figs. 2-4 is given in a volume relationship for a bulk density while the percentage content n of trotyl (Fig. i) is given with respect to mass. Results of measuring D for the mixture of 6GV with AN/GV are represented in Fig. i as a function of n. Experiments showed that AN/GV is capable of detonation in pure form for H = 20 mm even upon initiation by a standard electrical detonator without an intermediate warhead. The introduction of a definite quantity of 6GV into AT-1 can broaden the range of values of D substantially. The magnitudes of D for mixtures of AT-I with 6GV in the experiments agreed to 10% accuracy with the results of measuring the detonation velocity of the mixture of 6GV with AN/GV for an identical content of trotyl therein. Hence, the deduction can be made that the magnitude of D for trotyl-containin g mixtures based on ammonium nitrate is a function of just the percentage of trotyl content.