Modelling electro-impulse de-icing process in leading edge structure and impact fatigue life prediction of rivet holes in critical areas

摘要

The de-icing of a wing leading edge using an electro-impulse method benefits from its very low energy requirement and high efficiency. The high-frequency mechanical vibration activated by an electromagnetic pulse coil linked to an impulse circuit fractures the ice accumulating on the leading edge, and the ice is removed very rapidly when flying. An improved de-icing criterion based transient dynamics method is employed to accurately simulate the electro-impulse de-icing (EIDI) process. To reduce computational expenses in modelling all the rivet joints, a simplified model of leading edge structure ignoring all rivets is established using tie-constraints to identify high-stress areas or critical areas of leading edge structure during the EIDI process. Afterwards, a local detailed model of leading edge structure modelling rivets, rivet holes and their surfaces in critical areas, is set up to accurately describe the impact response and stress configuration of leading edge structure during the EIDI process. According to the EIDI local detailed model for leading edge structure, the fatigue life of critical rivet holes is predicted based on the local maximum stresses. Consequently, the endurance strength of the leading edge structure is estimated and a safe assembling scheme of the EIDI system is suggested.