Badania porównawcze liniowych ładunków kumulacyjnych

The fireground tests are the best method for verifying the operation effectiveness of the entire shooting device or its component parts in real conditions. The purpose of the fireground tests presented herein was the physical verification of linear shaped charge (LSC) ability to perforate multi-layered target, reflecting the material and geometrical conditions of a borehole. The series of shooting tests included tests of three types of linear shaped charges selected for use in perfo-fracturing devices. The following shaped charges were tested: LSC in lead enclosure, having φ = 40 mm circular cross-section with shaped recess; LSC with copper liner in 20/30 mm steel trapezoid enclosure; LSC with liner made of solid copper, in 20/40 mm steel trapezoidal enclosure.During testing, the cumulative jet velocity was recorded using voltage type probes, arranged between the individual layers of a target composed of steel and concrete materials. The research method adapted for the project purposes was aimed at verification of the following thesis: whether the proposed shaped charges fulfil the technical and performance conditions for their effective application in the oil industry. The criterion adopted was the ability – or lack of ability – to perforate the multi-layered barrier in the form of two steel plates and concrete casting. The testing stand, single-use by its nature, was each time composed of concrete block having 400 mm ´ 250 mm ´ 150 mm dimensions and 20 MPa static compressive strength, on which two steel plates were placed parallel to each other with 20 mm spacing. The thickness of the plates was 5 mm and 10 mm respectively. The tested shaped charge was placed on the top steel plate at a distance of one calibre – that is the distance equal to the opening of the trapezoidal shaped charge and full diameter of circular cross-section charge. Furthermore, within media interface planes (steel/air, air/steel; steel/concrete), the set of voltage-type measuring probes was installed, in the form of single electric wires (φ = 0.25 mm). At an instant when they break (circuit break) as a result of cumulative jet operation, voltage drop in the subsequent measuring probes will act as a logical gate of start-stop type, or in other words the zero-one (0–1) type gate. The readings of individual probes breakage times allowed in addition to determine the velocity of the cumulative jet and to estimate its braking dynamics while passing through the subsequent elements of multi-layered target.

Energy-Absorbing Capacity of Polyurethane/SiC/Glass-Epoxy Laminates Under Impact Loading

This paper presents the energy absorption of target materials with combinations of polyurethane (PU) foam, PU sheet, SiC inserts, and SiC plate bonded to glass fiber reinforced composite laminate backing during impact loading. SiC inserts and SiC plates are bonded as front layer to enhance energy absorption and to protect composite laminate. The composite laminates are prepared by hand lay-up process and other layers are bonded by using epoxy. Low-velocity impact is conducted by using drop mass setup, and mild steel spherical nosed impactor is used for impact testing of target in fixed boundary conditions. Energy absorption and damage are compared to the target plates when subjected to impact at different energy levels. The energy absorbed in various failure modes is analyzed for various layers of target. Failure in the case of SiC inserts is local, and the insert under the impact point is damaged. However, in the other cases, the SiC plate is damaged along with fiber failure and delamination on the composite backing laminate. It is observed that the energy absorbed by SiC plate layered target is higher than SiC inserts layered target.