The Use of a Railgun Facility for Dynamic Fracture of Brittle Materials

Abstract

Linear electromagnetic acceleration has a wide range of applications. Among them are applications in the field of materials science, where relatively small, inexpensive systems can be of high value. For instance, it was shown recently at the French-German Institute of Saint Louis, France, that the symmetric Taylor test-a method to investigate the deformation behavior of specimens at high deformation rates-can be realized with higher precision than attainable with other acceleration methods using a railgun with velocity control. In this paper, we present another example for an application of a railgun in the field of materials science, namely, the study of impact phenomena and terminal ballistics. One of the major advantages of railgun technology is that the acceleration profile can be well defined at velocity ranges from very low speeds (<10 m/s) up to more than 2000 m/s-for one and the same launcher. Moreover, the geometry of a railgun projectile can be round, rectangular or, as in the case discussed here, hexagonal. Finally, electromagnetic acceleration does not require the use of propellants, which in the case of impact experiments could lead to complications-at least for the experimental application presented. The quest is to study the ejecta field of fractured brittle materials at moderate impact velocities (<500 m/s). It transpires that a railgun can be a valuable tool for such investigations. Using high-speed cameras and novel data processing methods ejecta distributionvelocity relations are explored. Our contribution describes the experimental setup used and will introduce some of the major results obtained so far.

Characteristics simulations of the electrodynamic railgun different constructions and their measurement verification

“…The research on the electrodynamic accelerators (EA), commonly called railguns, concern mainly military applications and exploration of the space [1][2][3][4]. However, more and more studies are related to their applications in industry or measuring systems, like the impact testing of some materials [5][6][7][8][9]. Constructions of accelerators and their power supply systems are being tested [10], as well.…”

Influence of the different capacitor configurations of the supply system on the efficiency of the rail accelerator

“…Conventional gas systems for impact testing do not achieve the required energy and synchronisation parameters due to using gas to drive the impact member. The electro-magnetic gun overcomes these limitations as it allows precise control of the parameters of the armature [8][9][10][11]. The problem is in the costs.…”

Influence of the power supply parameters on the projectile energy in the permanent magnet electrodynamic accelerator

“…Mostly these researches were dedicated to military applications [3][4][5]. However, in recent years, the application of the accelerators in the material testing becomes more popular [6]. Studies on dynamic defragmentation of planetary materials [7] and hypervelocity material testing [8] by using an accelerator are carried out, especially.…”