Análise preditiva na detecção de falhas no rotor principal com foco na vibração em um helicóptero segundo a filosofia HUMS

Abstract

This work positions itself in the context of the technological development increasingly aggregated to the helicopter‟s market by HUMS (Health and Usage Monitoring System), whose philosophy brings, besides reducing maintenance costs, huge step forward in ensuring the continued airworthiness, and consequently in the flight safety level, preserving lives and material. Its associated innovations orbit around early failure diagnostics and predictions pointed to in real time by dedicated algorithms, by the processing of data collected by vibration sensors. From the possibility of ensuring, by predictive practices, an extension of the components useful life and the replacement of those before failure occur, emerges the motivation of this research. Its goal is to present a simplified analytical modeling for the analysis of vibration signal in the monitored structure of any rotorcraft for defects detection, equivalent to a hub blade unbalancing and out-of-tracking. Those degradations are the most common in the main rotor, the greatest source of periodic excitations transmitted to the fuselage, whose vibratory responses under analysis are limited to the 1 per rev fundamental frequency, which were numerically simulated in MATLAB(R) environment. The direct problem is presented in two parts: The rotor-fuselage system modeled as isotropic, followed by the part that introduces the anisotropies that simulate defects that generate vibration amplitude and phase information. The application of the model involves comparisons of the non-linear systems solutions with experimental data obtained by flight tests in a typical three-bladed rotor aircraft by means of simulation through measurements taken in two points of the fuselage as defined in the flight manual by the aircraft manufacturer.