Do we need to recourse to Ampere-Neumann electrodynamics to explain wire fragmentation in the solid state?

TL;DR

This paper investigates wire fragmentation in the solid state during high pulsed currents, demonstrating that flexural vibrations can cause breakage, questioning the necessity of Ampere-Neumann electrodynamics for explanation.

Contribution

It introduces a simplified magneto-thermo-elastic model showing flexural vibrations can explain wire disintegration without resorting to Ampere-Neumann electrodynamics.

Findings

Flexural vibrations are sufficient to break wires under certain conditions.

The model challenges the need for Ampere-Neumann electrodynamics in explaining wire fragmentation.

Wire disintegration can be explained by mechanical vibrations induced by pulsed currents.

Abstract

Exploding wires are widely used in many experimental setups and pulsed power systems. However, many aspects of the process of wire fragmentation still remain unclear. If the current density is not too high, the wire may break up in the solid state. In a series of papers, see references therein, Graneau argued that neither mechanical vibrations induced by the electromagnetic pinch force nor thermal expansion could have been responsible for the wire disintegration because they were too weak. To explain the phenomenon he appealed to the obsolete Ampere force law as opposed to the conventional Biot-Savart force law. Graneau argued that the Ampere force law would lead to a longitudinal tension in the wire, although his calculations may have been in error on this point. Therefore, Graneau's explanations induced a controversy in electrodynamics with a number of authors arguing pro and con. In this investigation, we use a simplified magneto-thermo-elastic model to study flexural vibrations induced by high pulsed currents in wires with clumped ends on account of their role in the disintegration process. It is shown that the induced flexural vibrations are strong enough to lead to the breaking of the wire in a wide range of parameters.