Loading...

Life Estimation of Helicopter Main Rotor Blades with Reliability Approach

Tavakoli, Mojtaba | 2025

93 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 58498 (45)
  4. University: Sharif University of Technology
  5. Department: Aerospace Engineering
  6. Advisor(s): Adibnazari, Saeed
  7. Abstract:
  8. Fatigue is one of the main causes of failure in helicopter components. A considerable portion of fatigue-induced failures is observed in the main rotor blades. In analytical relations for fatigue life calculation, many parameters are introduced as inputs, for which a fixed and deterministic value is usually considered. However, in reality, each parameter is associated with uncertainties, making it possible to assume different values with varying probabilities for each one. If these probabilities and uncertainties are taken into account in the problem, the probability of blade failure at any given fatigue life can be calculated using reliability analysis methods. In this research, aiming to investigate the reliability of blade fatigue life, several parameters including the Felix standard loading units, ultimate strength, and the fatigue strength coefficient and exponent were examined. By employing the Monte Carlo sampling method, the uncertainties of each parameter were incorporated into the analysis, and a set of multiple values for fatigue life was obtained. Based on the resulting data, the probability distribution function of fatigue life was derived, and accordingly, two diagrams of reliability and failure probability versus different life values were plotted. The results showed that the fatigue life of the blades, based on the reliability standard of 0.999999 (corresponding to a failure probability of one in a million), is 3955 hours. Using these findings, more informed decisions can be made regarding the utilization of blades, such as their retirement or continued operation after the completion of the standard life. In this way, it will be possible to enhance safety and improve the efficiency of the country’s helicopter fleet
  9. Keywords:
  10. Fatigue ; Reliability ; Monte Carlo Sampling ; Life Prediction ; Helicopter Main Rotor Blade ; Failure Probability

 Digital Object List

 Bookmark

...see more