NUMERICAL ANALYSIS OF AIRCRAFT STRUCTURE STRENGTH FROM THE STANDPOINT OF FATIGUE AND FRACTURE MECHANICS

Stevan Maksimović

Abstract
This information is focused on developing a numerical approach to the strength analysis of aircraft structures from the standpoint of fatigue and fracture mechanics. A computation procedure for life estimation of structural components under a general load spectrum is shown. Life estimation is analyzed for structural components with initial cracks. The analysis is carried out under cyclic loads with constant and variable load amplitudes. A special attention in this information is payed to life estimation of structural components from the aspect of the damage tolerance approach. A complete numerical procedure of life estimation is given. In order to determine parameters of fracture mechanics such as stress intensity factors analytic and numerical methods are used. The numerical method is based on conventional and special singular finite elements. In order to verify results of numerical simulations, experimental and other available results are compared. The obtained - good agreement means that the present computation procedure can be used in operational life estimation of cracked aircraft structural components. These numerical simulations of behavior of structural components with cracks in critical areas can reduce a risk of failures in aircraft structures.

Key words: aircraft, aircraft structure, structural analysis, isotropic materials, strength analysis, fatigue strength, fatigue, fracture mechanics, life estimation, numerical analysis, finite - element method.