Search results

Filters

  • Journals
  • Keywords
  • Date

Search results

Number of results: 2
items per page: 25 50 75
Sort by:

Abstract

From all the detonation parameters of explosives, “strength” – the capability to perform work is the most important for the user. The detonation of explosives in the blast hole is a quick and complicated process: first there is a detonation pressure causing the crushing of the rock in the vicinity of the explosive, then the pressure of the detonation products causes the cracking of the rock. The article presents the methods of determining the capability to perform work by explosives for civil use (dynamite and ANFO) used in the accredited Laboratory of Explosives and Electric Detonators Testing of the Experimental Mine “Barbara” of the Central Mining Institute – the lead block (Trauzl) method and the ballistic pendulum method. The aim of the research was to determine the relationship between the values of the capability to perform the work received in a ballistic pendulum method and a lead block method. As a result of the performed tests and the analysis of the results, the α-Pb coefficient was determined, which can be used to convert the value of the capability to perform work on the ballistic pendulum to the corresponding value of the capability to perform work in the lead block. At present, the Central Mining Institute is the only Notified Body of the European Union in the scope of Directive 2014/28 /EU, which has a station for smelting lead blocks and equipment and for determining the capability to perform work by explosives in lead blocks – this method was abandoned in other research units for testing with a ballistic pendulum and/or underwater test.
Go to article

Abstract

In this work, the author presents experimental verification of numerical simulation of projectile impact on constructional shields. The experimental tests were performed at a unified test stand to investigate ballistic resistance of materials in field conditions. The stand was developed at the Polish Naval Academy in Gdynia, and then patented. The design of this test stand was based on construction of a ballistic pendulum, fitted to measure: impact force, turn angle of the ballistic pendulum χ, impact velocity and residual velocity of the projectile. All the measurement data were transmitted to a digital oscilloscope and a personal computer. The ballistic velocity of the shield of VBL[R] – defined according to Recht’s and Ipson’s method, was compared with VBL[Z] and VBL[Z1] – determined according to the author’s method. Verification of numerically simulated ballistic velocity VRO versus the before-mentioned velocity was carried out at the 10GHMBA-E620T steel shields impacted by 12.7 mm type B-32 projectiles. The introduced method can be used for determining ballistic thickness hBL and ballistic velocity VBL for both homogeneous plates as well as multi-layered constructional shields.
Go to article

This page uses 'cookies'. Learn more