基于光纤光栅传感器的复合材料层合板冲击能量研究

摘要

Deteriorations which usually can not be detected from surface of composite material smart structure are often brought by low velocity impacts (LVI).By using the characteristic that the center wave-lengths of Bragg grating sensors in optic fiber composite material structure under LVIs are determined by stress, Bragg grating sensors were adopted for detecting the positions of LVIs which might cause damage on the structure in constant temperature.By analyzing the frequency spectrums of LVI signals captured by optic fiber grating demodulator, the peak value threshold of frequency spectrum for distinguishing energy classes can be figured out after calculating frequency spectrum peak values of all energy classes.The experiment proves that Bragg grating sensors can be used for monitoring impacts and detecting the grade energy of LVIs on composite material structure.%复合材料结构较容易产生结构表面无法探测到的低速冲击损伤.试验利用光纤复合材料结构中布拉格光纤光栅传感器受到低速冲击后光栅中心波长随应力变化这一特性,在恒温下用布拉格光纤光栅传感器对复合材料智能结构受到的低速冲击能量给出判别,并对通过光纤光栅解调仪采集下来的低速冲击信号进行频谱分析.在计算冲击信号所有能量等级的频谱峰值后,给出可以界定能量等级的频谱峰值临界值,利用其来判别低速冲击能量等级.试验表明布拉格光纤光栅传感器可以监测复合材料受到冲击的信号,能够对复合材料结构低速冲击进行能量等级判断研究.