Operational damage analysis, caused by fatigue of the material under the action of vibroacoustic loads, frames tail beams of Mi-8 helicopters
The paper presents the main results of the analysis of fatigue damage to the skin of the tail beams of Mi-8 helicopters. It is shown that after strengthening the tail beam skin in the areas of installation of the stabilizer and struts of the tail support, fatigue damage is most often detected in the area associated with the fairing of the antenna in the upper part of the tail beam between the frames No. 2-3, and between the frames No. 1-9 of the left and lower technological panels of the tail beam skin. In order to reduce the amount of fatigue damage in the skin of the tail beams, according to the results of the analysis, it is recommended to strengthen it in these zones. Analysis of the distribution of the total number of fatigue cracks detected in the tail beams skin, as well as the number of tail beams with cracks in the skin and reinforcing linings in the installation area of the antenna fairing and its associated zones by operating time since the beginning of operation, allowed us to identify the intervals of operating time at which a change in the intensity of fatigue cracks formation is observed in the considered areas of the tail beam skin