Development of a Practical Fatigue Analysis Methodology for Life Prediction of Rotary-Wing Aircraft Components.

Abstract

A practical fatigue analysis methodology was developed for predicting the life of rotary-wing aircraft components. The focus of this fatigue capability was two-fold. First, to gain insight into the current life prediction methodologies and their use, and second, to be able to predict the service life of aircraft components and determine if reworked parts are suitable for continued service. Commercially available software, ANSYS and Fe-safe, were utilized as the finite element and fatigue life prediction solvers, respectively.

It was demonstrated that the predicted fatigue life on aircraft components can be performed with reasonable accuracy and efficiency by utilizing commercially available software. This methodology was first demonstrated by investigating the predicted fatigue life of a flat plate with a centrally located hole under constant amplitude and variable amplitude loading. This approach was validated by comparing simulated life predictions using several stress-life and strain-life algorithms with previously published experimental data. In addition, an illustrative helicopter main gear drag beam was analyzed and the effect on fatigue life due to a reduction in the beam thickness was demonstrated.

This research had demonstrated that a fatigue life methodology can be successfully utilized to predict the service life of aircraft components in a practical manner and to determine if reworked parts are suitable for continued service.