CONTRIBUTIONS OF LIGHTNING CURRENT PULSES TO MECHANICAL DAMAGE OF CFRP STRUCTURES

摘要

The lightning direct effects on metallic materials are described within a thermo-electrical framework that has been extended to describe the thermo-mechanical damage of continuous lightning current components of CFRP structures. It is shown, that the thermo-electrical approach needs to be supplemented or even replaced by force concepts for describing mechanical damage of CFRP structures caused by the transient lightning current components. An analysis of the damage mechanism of CFRP structures due to transient lightning strike current components is given with focus on the main non-thermal damage mechanisms: the magnetic forces, the shock waves due to supersonic channel expansion, and the shock waves due to near surface-explosions. Moreover, a numerical model for the arc root radius expansion during the transient lightning current component is developed as well.