Research On Aeronautical Material Fatigue Life Simulation And Prediction

The aviation industry keeps developing at a high speed these years. However, as aircrafts get old, the fatigue failure of aeronautical materials has become a critical problem, threatening the safety of aircrafts. An accurate fatigue life prediction of aeronautical materials is thus vital to the reliability of aircrafts.A static traction experiment and several groups of low cycle fatigue experiments are done with No.45 steel standard samples in order to collect its mechanical and fatigue performance data. Fatigue life prediction formulas are drawn with the experiment data on the basis of plastic strain energy and total strain energy method to verify the applicability of the two methods on No.45 steel fatigue life prediction. Finite Element Analysis software Patran and Nastran are used in cooperation with LMS Virtual.Lab Durability to simulate the No.45 steel low cycle fatigue experiments.A rigid-flexible coupled landing gear drop simulation is performed on the basis of a landing gear multi-rigid body model in Virtual.Lab Motion. The result of the dynamic analysis is used directly to do a system-level fatigue analysis in Durability. Fatigue failure hot spots are detected and local tensor history is analyzed to find the key modal load to local fatigue damage. The length of the arm is then modified and the strut fatigue life is reanalyzed to study the influence of the arm length on the strut fatigue life.This paper puts forward a way to do systematical interdisciplinary fatigue life prediction and product design on the Virtual.Lab platform.