On the characteristics of lightning currents in the steel reinforced concrete building due to a lightning strike

Lightning is the natural phenomenon which brings huge quantity of charge to earth. It is a well known fact that lightning mostly strikes elevated objects. It is found that significant amount of current is induced in the simple vertical down conductor when lightning strikes directly or in the vicinity. The steel rods in the steel reinforced concrete buildings act as down conductors. Therefore the current induced in them may affect the operation of sensitive electronic devices in the building due to interference. Hence it is required to determine the magnitude and the nature of lightning currents in them. Therefore present work is carried out to study the basic characteristics of lightning generated currents. The study was carried out with the assumption that there are no influencing components in the vicinity of the building and the lightning strike and electrical connections in the building are through cable ducts. Electromagnetic model is employed and NEC-2 is used for the numerical field computations. It is found that the large amount of current is induced in the pillars and beams of the building and it depends upon various pertinent parameters.