No abstract

No abstract

Newly formulated explosives and the optimization of explosive mixtures requires an experimental determination of detonation parameters, especially detonation velocity, pressure and metal accelerating ability. Increasing material and labour costs force researchers to reduce test quantities and therefore to develop smaller scale experiments which provide sufficient data to determine an explosive’s properties. Seven test set-ups found in literature are described and compared in this paper.

PlSEM is a plastic explosive based on RDX, PETN and a nonexplosive binder, and is used in linear shaped charges for demolition purposes. Its experimentally obtained detonation parameters are presented in the present paper. The detonation velocity was measured for cylindrical charges of various diameters, with and without confinement. The detonation pressure and particle velocity were determined using an impedance window matching technique, and cylinder tests were used to obtain the parameters of the JWL equation of state of the detonation products. Detonation velocities from 7.75 to 8.05 km·s -1 were obtained for unconfined charges with diameters from 4 to 8 mm, and from 8.15 to 8.24 km·s -1 for charges with 25 mm diameter. The experimentally determined detonation pressure was found to be 24.6 GPa.

Two important parameters reflect in the quality of the interface of two explosively welded metal plates – impact velocity and collision angle. Both parameters can be determined from the knowledge of velocity history of the accelerated surface. A suitable measurement methodology that would allow in‐situ determination of the course of acceleration at a technological scale experiments is however not yet available. One of the emerging options enabling such measurements is Photonic Doppler Velocimetry (PDV). This paper focuses on the issues observed during measurement of metal plate acceleration in explosive welding using this technique. A well‐known combination in which copper plate is accelerated by detonation and welded to a steel baseplate was chosen for small scale experiments. The methodology was further employed at a large scale technological tests were two different steel plates were joined by detonation. The PDV proved to be successful in determination of the entire velocity history and provides unprecedented insight into the welding process. The knowledge of the velocity time history enables optimization of the impact velocity and collision angle without having to modify the explosive composition. A methodology of velocity measurement of the entire velocity profile of accelerated plate and its collision velocity during metal welding was developed. In addition, we are proposing a new way of optimizing welding parameters based on the exact velocity and thus a collision angle calculation.