Analysis Of Fatigue Characteristics Of A Certain Type Nose Landing Gear

Landing gear is the critical component for aircrafts'flight safety. According to statistics the accidents caused by landing gears or associated with landing gears account for approximately two thirds of these accidents. The design of landing gear is an important component of aircraft design. The core issues of landing gear structure design develop from the initial static strength and stiffness design to how to design a landing gear with long-life, high reliability and low maintenance costs. So the concept of fatigue strength and durability design of landing gear is introduced.A deeper research on fatigue characteristics of landing gear is conducted in this paper. First analysis of the static mechanical properties is taken and some parts with stress concentration to be destroyed are found out. Secondly pursuant to the steps of virtual fatigue,analysis estimation of landing gear fatigue life is done at the following aspects of total life, strain fatigue life, crack propagation fatigue life and vibration fatigue life and so on. Therefore, the life of landing gear and some failure parts are got. The analysis results prove that this landing gear's fatigue characteristic meets the requirement of our design. Finally as for some key parameters with great impact on the life of landing gear,optimal design is done.The method to analyze the fatigue characteristic of landing gear structures from the whole landing gear to its structural details in the integrated use of Adams and Nastran/Patran, Fatigue software is discussed in the research. First the dynamic performance of the overall landing gear is analyzed so that the constraints of the structural details are gotten. Then the finite element anaysis is done by building the finite element model with high quality mesh of these structural details and imposing appropriate constraints to the model. Finally the fatigue properties and the influencing factors are studied in fatigue software. The method can also be applied to analyze the structural details'fatigue characteristic of other complicated mechanism.