The method of determining the characteristics of the general stress-strain state of the tail boom Transport Category Helicopters

Abstract

A method for determining the characteristics of the general stress-strain state of a helicopter tail boom, taking into account cutouts and reinforcing plates, has been developed, which includes the creation of a three-dimensional parametric finite element model, the design of the tail boom is presented, a calculation scheme for the tail boom of a transport category helicopter has been developed, and a finite element model.

In the practice of world helicopter construction, single-rotor helicopters are most widely used, which are characterized by relative simplicity of design, convenient control and relatively low cost. The tail beam is the most complex part in the production of a helicopter. For a single-rotor helicopter, the tail beam is a very critical part of the structure, the destruction of which in most cases leads to an aviation accident. Ensuring the requirements for strength is an extremely responsible task, therefore it is regulated by the airworthiness standards mandatory for designers, which are an integral part of the Aviation Rules. These standards set the initial requirements for the calculation and experimental work to ensure strength, determine the loading conditions, and give instructions for determining the magnitude of the loads. In the practice of helicopter construction, the experience accumulated in aircraft construction in forming structural and power schemes of frame units is used.

One of the main tasks of modern aviation science is the creation of a rational structural and power scheme of helicopter units, which makes it possible to achieve high indicators of weight efficiency and structural resource. This scientific problem is solved by studying the stress-strain state of the structure analytically, numerically or experimentally. Numerical modeling is increasingly and widely used in the design of aircraft structures to determine the optimal parameters at given operating modes. The main numerical method that has become widespread in engineering calculations is the finite element method.

The main design case for the tail boom is the exit from a dive. The corresponding design load cases acting on the helicopter's tail boom are determined as a result of calculations performed in accordance with the requirements of the aviation rules and other regulatory documents for the creation of a transport category helicopter, as well as the results of tests.