Observation and verification of surface electrical explosion driven by radial‐distributed pulsed current in laboratory lightning strike test

Abstract The laboratory lightning test is essential for assessing the effectiveness of strike protection (LSP). Particularly, direct damage can be performed with pulsed current injection into specimen. This paper focuses on dynamic process arc plasma and shock wave behaviour in vicinity ‘strike’ point. A rod‐plate discharge load built testing aluminium coated plate under 40‐kA‐level current. visualisation luminous its flow field via high‐speed photography (from different angles) meticulously designed implemented, synchronised electro‐physical diagnostics. results indicate some new mechanisms damage, apart from impulse heat loading thermal arc. transient through root concentrates a thin skin layer (skin‐depth effect), radial‐attenuated density, driving asynchronously electrical explosions surface. inhomogeneous Joule heating leads to outwardly propagating phase transition along conductive In addition, electro‐thermal instability observed regarded as seed irregular erosion region. Spectroscopic information reveals two states main channel adjacent surface explosion. correspondence physical mechanism explosion optical radiation established. Microscopic images regions depict characteristics summarise influencing factors, further confirming above. research clarifies role skin‐depth effect transaction electrode, complements theory unevenly distributed helps optimise strategies LSP.