Twisting of the Tail Rotor Shaft - A Case Study
Presented results report the findings of a case study carried out to determine the possible factors that lead to the twisting of tail rotor shaft. The structural materials of the shaft was evaluated in terms of microstructural analysis and mechanical properties to rule out any material fault. The SEM images showed that the localized fractures at twist ends occurred without any significant plastic deformation. Moreover, there was no evidence of fatigue. Such behavior suggests that twist occurred under impact / high strain rate loading. Such loading conditions are not possible during the event to ground hitting. The Ansys simulation confirmed that the observed twisting can increase the stress at localized point in excess of UTS and cause fracture.
M. Muneeb Asim, M.B. Bhatty, M. Mansoor and Ejaz Ahmed Mukhtar
M. Shahzad et al., "Twisting of the Tail Rotor Shaft - A Case Study", Key Engineering Materials, Vol. 778, pp. 28-32, 2018