基于HHT的机翼盒段的健康监控

提出了一种基于HILBERTHUANG变换技术的结构微损伤检测方法.基于HHT方法,提取了同损伤相联系的特征量-瞬时频率变化量和瞬时能量变化量.给出了结构损伤前后瞬时频率的变化情况,根据结构损伤前后瞬时频率的变化量,可以判断结构发生了一定程度的损伤.最后研究了结构损伤前后瞬时能量的变换情况,并讨论了瞬时能量变化最大值与结构损伤程度之间的关系.结果表明,结构原始响应信号经过HHT变换后得到的瞬时能量变化最大值与结构损伤程度有一定的规律可寻.

HHT based health monitoring of wingbox section

An approach for detecting the tiny damage of a structure was proposed. Based on the Hilbert-Huang Transform, the structural damage feature index, i.e., the variation of instantaneous frequency and of instantaneous energy, were extracted, and the dynamic response signals of the composite wingbox excited under a square wave signal were calculated. IMFs of the dynamic response signal were decomposed using EMD method, and the instantaneous frequencies corresponding to IMFs were calculated. The variation of the instantaneous frequencies can be used to judge whether or not the structure is damaged. Hilbert spectrums of the dynamic response signals were obtained using HHT method , and the instantaneous energy corresponding to Hilbert spectrum was calculated, from which the damage information, i.e. the variety quantity of instantaneous energy, can be extracted. And the relationship between the proposed damage feature index and the structural damaged degree was given.