Dai Yutang, Yin Guanglin, Liu Bin, Xu Gang, Karanja Joseph Muna
Appl Opt. 2015 Apr 10;54(11):3115-21. doi: 10.1364/AO.54.003115.
To meet the requirements for medium-high frequency vibration monitoring, a new type fiber Bragg grating (FBG) accelerometer with an integrative matrix structure is proposed. Two symmetrical flexible gemels are used as elastic elements, which drive respective inertial mass moving reversely when exciting vibration exists, leading to doubling the wavelength shift of the FBG. The mechanics model and a numerical method are presented in this paper, by which the influence of the structural parameters on the sensitivity and eigenfrequency is discussed. Sensitivity higher than 200 pm/g and an eigenfrequency larger than 3000 Hz can be realized separately, but both cannot be achieved simultaneously. Aiming for a broader measuring frequency range, a prototype accelerometer with an eigenfrequency near 3000 Hz is designed, and results from a shake table test are also demonstrated.
为满足中高频振动监测的要求，提出了一种具有一体化矩阵结构的新型光纤布拉格光栅（FBG）加速度计。采用两个对称的柔性铰链作为弹性元件，当存在激励振动时，它们驱动各自的惯性质量反向运动，从而使FBG的波长偏移加倍。本文提出了力学模型和数值方法，讨论了结构参数对灵敏度和固有频率的影响。灵敏度可单独实现高于200 pm/g，固有频率大于3000 Hz，但两者不能同时实现。为了获得更宽的测量频率范围，设计了一种固有频率接近3000 Hz的加速度计原型，并展示了振动台测试的结果。
