IL CONTROLLO DEL RISCHIO DI DANNO PER FULMINAZIONE DIRETTA DELLE STRUTTURE.

The paper deals with the criteria of assessment and control of the complex risk of damage due to lightning stroke for structures. Some typical events of damage are considered: triggering of explosive or inflammable environment by melting or glowing of striken conductors and/or by corona or side flash; mechanical damages; shock hazard for people by intolerable touch and step voltages; damages or malfunctioning of electrical and electronic equipment. A general idea of the method and the essential rules to assess the complex risk, taking into account the selectivity of lightning strokes and the probability of damage, are presented and discussed. In order to show how the method can be applied for the control of the risk of damage, a case of a structure protected by lightning installation is considered. The most critical components of damage are identified and the improvement of lightning protection efficiency is suggested in order to reduce the risk to a tolerable level.