Analysis of degradation model of butterfly resonator gyroscope (BRG) is essential to predict its reliability. In order to establish the degradation model of the BRG, three parts of investigation are conducted. Firstly, an analytical model is developed to describe the effect of residual stress on the resonant frequency of excitation mode for BRG. Modal analysis of the BRG under different residual stresses (29 groups) is also simulated by finite element method (FEM), and the FEM results are close to the proposed analytical model within the range of residual stress (−24 MPa to 70 MPa). Secondly, the degradation models of resonant frequency at excitation mode and mechanical sensitivity of BRG are developed based the analytical model. Finally, the long-time static test of four BRGs at same environment temperature is designed and carried out. The test results show that the resonant frequency and mechanical sensitivity of the BRG decreases gradually with time increasing, which is consistent with the results of numerical simulation. Based on the degradation model of mechanical sensitivity, the mechanical sensitivity would degrade by 20.27% in 10 years. This work contributes to reliability evaluation and life prediction of BRG. [2019-0202]

中文翻译：

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蝶形谐振陀螺仪谐振频率和机械灵敏度退化模型的研究

蝶形谐振陀螺（BRG）退化模型的分析对于预测其可靠性至关重要。为了建立BRG的退化模型，进行了三个部分的调查。首先，建立了一个分析模型来描述残余应力对 BRG 激励模式共振频率的影响。BRG在不同残余应力（29组）下的模态分析也采用有限元法（FEM）进行模拟，在残余应力范围（-24 MPa至70 MPa）内，FEM结果与提出的分析模型接近。其次，基于解析模型建立了激励模式谐振频率和BRG机械灵敏度的退化模型。最后，设计并进行了4个BRG在相同环境温度下的长时间静态测试。测试结果表明，BRG的共振频率和机械灵敏度随着时间的增加而逐渐降低，与数值模拟结果一致。根据机械灵敏度退化模型，10 年机械灵敏度将下降 20.27%。这项工作有助于BRG的可靠性评估和寿命预测。[2019-0202]