Dynamic response and failure damage of helicopter tail drive shaft projectile impact

DOI:	10.11809/bqzbgcxb2024.05.018
Keywords:	tail drive shaft; projectile impact; penetration velocity; failure damage; time interval between two peak impact forces
Abstract:	The tail drive shaft of helicopter is easy to be hit by ground weapon during a low altitude fight, which will result in projectile impact damage. In order to obtain the effects of projectile incidence angle and velocity on the dynamic response and failure damage of the tail drive shaft, the finite element model of projectile impact dynamics was established for the tail drive shaft. And the accuracy of finite element model was verified by combined with experiments. The failure damage pattern of the tail drive shaft was analyzed at different incidence angles and velocities of the projectile. And the critical penetration velocities of the convex and concave surfaces of the tail drive shaft were calculated for different incidence angles of the projectile. Besides, the relationship between the projectile angle of incidence, velocity and the two impact force peaks as well as their time intervals as a function of change was obtained. A method for estimating the impact parameters of the projectile was proposed. The results of the analysis show that the failure damage form of the tail drive shaft is in the form of a backward flipped petal type. Projectile exit holes are more damaged than entry holes. The critical penetration velocities of both the convex and concave surfaces of the tail drive shaft increase with projectile incidence angle. When the projectile velocity is much greater than the convex concave face boundary penetration velocity or positive impact, the trajectory is not significantly deflected. The peak of impact force decreases with increasing projectile incidence angle and increases with increasing projectile velocity. However, the time interval between the two peak impact force increases with increasing projectile incidence angle and decreases with increasing projectile velocity. Based on the time interval between the two peak impact forces and the distance travelled by the ballistic trajectory, the impact parameters of the projectile can be effectively estimated with an error of less than 5%. These will provide a reference for online monitoring of the tail drive shaft projectile impact status, and ensure the safe flight and mission execution of helicopters in harsh battlefields.
Issue:	Vol. 45 No. 5 (2024)
Published:	2024-05-31
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