Effects of Single Impulse Current and Multiwaveform Multipulse Currents on Aluminum Alloy in Lightning Damage Analysis

Abstract

Investigating the effects of single impulse current (SIC) and multiwaveform multipulse currents (MWMPCs) on metal contributes to the body of knowledge on lightning damage characteristics and mechanisms. This information is the basis for lightning protection of metal-made structures such as oil tanks, wires, and aircraft. In this article, three typical impulse currents, the 30-/80- $\mu \text{s}$ waveform current with amplitude of 150 kA, the 2-ms square-waveform current with amplitude of 2 kA, and the 520-ms rectangular-waveform current with amplitude of 404 A, are individually generated to inflict damage to aluminum alloy (Al 3003) for studying the effects of different lightning currents. Results are further compared to the continuously combined application with MWMPC, which is more close to real lightning. The damaged area of alloy suffered from the combined application experiment is 3156.0 mm2 and damaged depth is 4.7 mm, increased by 15% and 42% compared with the extreme results of individual application. In the MWMPC experiment, oxygen content increases to 35.6% and microhardness grows to 78.5, 21% and 2% higher than the extreme in SIC experiments. Damage deepening effect and crack intensifying effect are discovered in the combined MWMPC experiment. This article provides data for lightning protection and damage modeling.