飞机复合材料敲击检测信号的小波去噪新方法

New Wavelet De-noising Method Based on Tap Detection Signal of Aircraft Composite Materials

为了利用小波阈值函数研究飞机复合材料敲击检测信号的去噪处理,在敲击检测简化力学模型中,推导出飞机复合材料表面受到瞬时激振的振动信号表达式.在硬阈值函数、软阈值函数、半软阈值函数和两种改进阈值函数去噪法的研究基础上,提出了基于硬阈值函数和半软阈值函数线性结合的阈值函数去噪新方法.在时域和频域的振动信号去噪仿真和对比结果表明,新方法在函数连续性、波形平滑度、重构误差等方面的去噪效果都同时得到了较大的提高,去噪效果显著.为飞机复合材料敲击检测信号去噪提供一种技术方法.

In order to research tap detection signal de-noislng of aircraft composite with wavelet threshold func- tion, in the simplified mechanical model, we derived the vibration signal expression of instantaneous excitation on the aircraft composite surface. Based on the de-noising research results of the hard threshold function, the soft threshold function, semi soft threshold function and two kinds of improved threshold function, we put forward the new de-noising method of threshold function with hard threshold function and semi soft threshold function based on linear. The simulation and comparison results of the vibration signal in time domain and frequency domain showed that the new method also improved significantly in function continuity, smoothness, waveform reconstruction error and other aspects of the de-noising effects. Weprovide a technical method for the tap detection signal de-noising of aircraft composite materials.