Analysis of the stressed and deformed condition of power elements of the mounting of the Mi-8 helicopter reducer in the presence of corrosion damage
DOI:
https://doi.org/10.54858/dndia.2023-19-28Keywords:
stress-strain state, modeling, fatigue strength, corrosion of duralumin alloys, corrosion damage, mounting bracket for hanging fuel tanksAbstract
The article presents the results of the analysis of the stress-strain state of the mounting bracket of the outboard fuel tank of the Mi-8 helicopter in the presence of corrosion damage. Simulation of the stress state of the mounting bracket of the hanging fuel tank in the presence of corrosion damage was carried out. The results of the simulation will make it possible to make a more balanced decision, during the continuation of the specified indicators in the conditions of operating organizations, about the admission to further operation of the mounting brackets of the outboard fuel tanks of Mi-8 helicopters with existing or removed corrosion lesions that exceed the dimensions provided for in the operational documentation.
At present, the state aviation of Ukraine has a certain system for maintaining the airworthiness of the helicopter fleet for maintaining and restoring the serviceability of Mi-8 helicopters. During the assessment of the technical condition of Mi-8 helicopters, in the conditions of operating units, in order to continue the specified indicators, significant corrosion damage to the attachment of the outboard fuel tanks is often found, which exceed the values determined by the repair documentation (in terms of depth and area).
The specified corrosion damage occurs due to the design features of the mounting of the hanging fuel tanks. Due to the ingress of moisture between the iron and the lining of the central part of the fuselage, moisture falls on the gasket between the tank and the bracket, which is made of felt. Moisture stays in the felt for a long time and causes significant corrosion damage. After the removal of the mentioned corrosion lesions, the question arises about the possibility of further operation of the brackets as intended.
For this, it is necessary to answer the question about the stressed state (residual strength), which occurs during operation in brackets with quite certain corrosion lesions that exceed the permissible standards.
The purpose of the work was to determine the effect of corrosion damage on the stress state of the bracket structure. It was achieved using the method of mathematical modeling of the structure of the mounting brackets of the suspended fuel tank under load in the presence of corrosion.
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