基于杠杆放大机构的光纤光栅中高频地震检波器

Fiber grating medium-high frequency seismic geophone based on lever amplification mechanism

摘要:

为解决在中高频地震信号勘探检测中,检波器存在的高固有频率与低灵敏度的矛盾, 提出了一种基于杠杆放大机构的光纤光栅中高频地震检波器。在惯性质量块的一端链接杠杆放大机构,光纤光栅以两点式封装法竖直固定在杠杆的放大端与基底之上。杠杆放大机构可以在检波器的输出端产生机械放大,增加光纤光栅的轴向应变,增大对地层中微弱中高频信号的响应,从而提高检波器的灵敏度。同时检波器的机械结构使用一体化加工工艺,可提高机械结构的刚度与稳定性。实验测试表明,该检波器的固有频率为526 Hz,在20—260 Hz的频率范围内,灵敏度为119.108 4 pm/g,同时具有良好的横向抗干扰性能。 这为中高频段载震检波器的研究 提供了一定的技术思路和方向。

Abstract:

To solve the conflicting problem of high natural frequency and low sensitivity of geophones in the exploration and detection of medium-high frequency seismic signals,a fiber grating medium-high frequency seismic geophone based on a lever amplification mechanism is proposed.One end of the inertial mass block is connected to the lever amplification mechanism,and the fiber grating is vertically fixed on the amplification end of the lever and the base using a two-point packaging method.The lever amplification mechanism can produce mechanical amplification at the output end of the detector,increase the axial strain of the fiber grating,and increase the response to weak medium-high frequency signals in the formation,thereby improving the sensitivity of the detector.At the same time,the mechanical structure of the detector uses integrated processing technology,which can improve the rigidity and stability of the mechanical structure.Experimental tests show that the natural frequency of the detector is 526 Hz,the sensitivity is 119.1 084 pm/g in the frequency range of 20—260 Hz,and it has good lateral anti-interference performance.It provides certain technical ideas and directions to study the medium-high frequency seismic geophone.