民机金属结构地空地不变的载荷谱加重方法

Load Spectrum Enhancement Method with Ground-Air-Ground Invariance of Aircraft Metal Structure

全尺寸疲劳试验是飞机研制过程中必不可少的一个环节,但是其过长的试验周期已成为制约型号研制的瓶颈。本文提出了地空地不变的加重方法及寿命反推方法,能在保证地空地载荷不变的情况下提高每块谱的损伤,减少总循环块数,达到缩短试验周期的目的,同时可用加重谱反推原谱寿命。本文选取某型飞机外翼放油口部位进行验证试验,在加重1.2倍的情况下,用加重后的疲劳寿命反推原谱疲劳寿命,破坏部位和原谱下破坏部位相同,寿命反推结果与试验结果的误差在工程可接受范围内,说明本加重方法具有一定的工程实用价值,可供后续研究人员使用。

Full-scale fatigue test is an essential link in the process of aircraft development,but its long test cycle has become the bottleneck of aircraft development.In this paper,the load spectrum enhancement method with ground-air-ground and the life prediction method are proposed,which can improve the damage of each block spectrum,reduce the number of the total circulation blocks and shorten the test period under the condition of ensuring ground-air-ground invariance.At the same time,the life of the original spectrum can be deduced by means of the enhancement spectrum.In this paper,a certain type of aircraft is selected to carry out the verification test at the outer wing.Under the condition of 1.2 times heavier,the original spectrum fatigue life is deduced by using the enhancement fatigue life,and the damage position is the same as that under the original spectrum.The error between the result of life prediction and the result of test is within the acceptable range of engineering,which shows that this method has some practical value in engineering and can be used by later researchers.