Protecting Electronic Equipment in Composite Structures against Lightning

M.A. Blaj

    Research output: ThesisPhD Thesis - Research UT, graduation UT

    371 Downloads (Pure)

    Abstract

    Damage resulting from an interaction with lightning current in a military naval vessel, especially in a conflict zone and at the time of a conflict, which leads to the incapacitation of vital activities on the ship, is unacceptable. Because many potential conflict zones are in littoral areas, and because of the increase in lightning activity, both now and expected in the years to come, the provision of protection for naval vessels sailing in those waters should be a high priority. The fact that many standards exclude both naval vessels and the littoral area transforms this work into a potential contemporary solution. With the knowledge about the formation of charge layers in the atmosphere, and about the influence such weather phenomena as fog, clouds, and aerosols have on the transport of additional charge particles, it is possible to understand the formation of lightning. A review of the existing thunderstorm prediction models, and finding a way to verify and update the accuracy of such, is equally important at this stage. Merely understanding the root cause of the problem will not be enough to solve the problem, and therefore an extensive evaluation of the available literature, with a special attention to standards, also has to take place. Evaluating risks and finding what was previously accomplished by others, and any stones they have left unturned, can improve the life expectancy of a system or building block when applying and improving the existing technology. Conventional lightning protection measures serve as points of departure to reach the goals of this research. Such issues as positioning, zoning, and proximity to other components more attractive to lightning strikes must not be overlooked since these are equally important. The rolling sphere concept, as described in civil standards, is applied to naval vessels, and serves now as a basic tool within THALES to estimate the risk of lightning, and possible damage and/or interference. Steps taken by other branches of industry in this direction is investigated too. Investigation and a thorough analysis of other protective methods will help to generate the right ideas to tackle the issue and to improve lightning protection of electronics enclosed by composite structures against both direct contact with the lightning current, and the indirect effects of the associated electric and magnetic fields. Diverters are used by the aircraft industry and the possible use to protect radars under a composite non-conducting radome has been investigated experimentally. The constant increase in our dependency on composite panels throughout many branches of industry, including the naval and maritime sectors, make it necessary to quantify and measure all the risks associated with lightning strikes. Evaluating risks, and where necessary fixing them, will guarantee the successful use of this technology. The lack of shielding properties, and the high likelihood of deterioration and damage as a result of a lightning attachment, mean improvements are essential to make the use of complete fiber reinforced polymer (FRP) composite structures completely safe. A novel idea has been presented, and evaluated via modelling and simulation, as well as via experiments, where the shielding properties of thin materials is used in combination with the coupling of the electromagnetic field, as generated by the lightning strike, into cabling. It has been shown that a smart combination of the shielding and coupling aspects can be very beneficial. Another novel concept is the use of pre-loading of ball bearings. This pre-loading results in a continuous conducting path between the rotating and static part, such that no sparks and hence no damage will occur. A patent application has been filed by THALES Nederland.
    Original languageUndefined
    Awarding Institution
    • University of Twente
    Supervisors/Advisors
    • Leferink, Franciscus Bernardus Johannes, Supervisor
    Thesis sponsors
    Award date18 Jun 2015
    Place of PublicationEnschede
    Publisher
    Print ISBNs978-90-365-3858-9
    DOIs
    Publication statusPublished - 18 Jun 2015

    Keywords

    • IR-96062
    • METIS-310671
    • EWI-26177

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