利用分段积分识别阻尼比研究

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振动与冲击 ›› 2015, Vol. 34 ›› Issue (20) : 109-114.

论文

利用分段积分识别阻尼比研究

赵晓丹，徐俊杰，王西富

作者信息 +

A method for damping identification using piecewise integral

ZHAO Xiao-dan，XU Jun-jie，WANG Xi-fu

Author information +

文章历史 +

摘要

提出利用分段积分列方程识别阻尼比方法。用快速傅里叶变换加连续傅里叶变换(Fast Fourier Transform plus Continuous Fourier Transform，FFT-FT)识别响应信号固有频率，并据此构造复指数函数；与响应信号进行两次时间不同的内积运算，控制运算时间为响应信号半周期整数倍；推导衰减系数计算公式，识别阻尼比。该方法具有控制内积运算时间消除负频率项影响特点，不受阻尼大小、采样长度限制，识别精度高，结合迭代运算能识别密集模态阻尼。仿真计算、实验表明，在曲轴阻尼实验中，该方法能准确识别阻尼的微小变化，具有工程实用性。

Abstract

A method using piecewise integral to identify damping ratios is proposed. Natural frequency of response signal is calculated by the application of Fast Fourier Transform plus Continuous Fourier Transform (FFT-FT). Construct a complex exponential function with the calculated natural frequency, and two inner product which have different integral time were conducted between response signal and the constructed exponential function. Control the time of inner product to be integer time semi-period of the response signal, and the formula of attenuation coefficient was derived. Accordingly, the damping ratio can be determined. Feature of this method is that interference of negative frequency item was eliminated by controlling the time of inner product. This method is not restricted by the size of damping ratios and the length of sample, and it has high precision. Damping ratios of closely spaced modes can be identified by this method combined with iterative algorithm. Digital simulations and experiment show that this method is effective. In Crankshaft experiment, small changes of damping ratios were identified. This method is practical in engineering.

导出引用

赵晓丹，徐俊杰，王西富. 利用分段积分识别阻尼比研究[J]. 振动与冲击, 2015, 34(20): 109-114

ZHAO Xiao-dan，XU Jun-jie，WANG Xi-fu. A method for damping identification using piecewise integral[J]. Journal of Vibration and Shock, 2015, 34(20): 109-114

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