Investigating the lightning resistance of composite materials for ensuring safe operation of transport infrastructure facilities

Abstract

Abstract The article reviews a destructive effect of the lightning current impulse on composite materials widely used in automotive, power and aerospace industries. It is argued and substantiated that it is improper to use a standard impulse simulating the effect of a lightning strike. For better simulation of lightning current effect, results of experiments with regard to lightning strike current, performed at the Santis tower (Switzerland), in the course of which a slow part of lightning strike was discovered (besides the fast one), are used. An approach to create a generator of current impulses with waveforms similar to those recorded during full-scale experiments is presented. Two options of the impulse generator are compared: a generator with an accumulating inductor and a two-stage generator with preliminary separate charging of the “quick” and “slow” stages. The authors opt for the latter. Test results with regard to the selected option, confirming that generated current impulses are similar to those obtained during full-scale experiments, are presented. Results of specimen destruction with current impulses of various waveforms are provided. It is shown that current impulses with waveforms similar to those recorded during full-scale experiments cause more destruction to composite materials than standard impulses. The necessity to perform lightning resistance tests regarding composite materials, used to manufacture systems and devices for the transport industry, in terms of the effect of current impulses with waveforms similar to those recorded during full-scale experiments, is acknowledged.