基于小波变换的汽车零部件加速耐久性载荷谱编辑方法研究

Study of Load Spectrum Edition Method Based on the Wavelet Transform to the Accelerated Durability Test of the Vehicle Component

介绍基于小波变换的汽车零部件加速耐久性载荷谱编辑方法的研究。利用Daubechies小波函数(db12)对零件的载荷谱信号进行小波分解,得到不同尺度下的高频和低频下的小波系数,对高频小波系数进行重构,得到高频小波分量。基于分解后高频小波分量,利用包络线损伤识别法,将损伤贡献较大的信号片段从原始信号中识别并提取出来,通过编辑得到零件的压缩载荷谱。以汽车动力总成悬置的载荷谱为例,进行了基于小波变换和基于损伤保留两种方法的编辑。结果表明,基于小波变换的载荷谱编辑方法得到的压缩载荷谱在统计参数(均值、方均根与峰值系数)、能量及信号的幅值分布等方面均与原始载荷谱吻合,可以达到与原始载荷谱相同的加载效果,说明该编辑方法可用于汽车零部件的加速耐久性试验研究中。

The load spectrum edition method based on the wavelet transform to the vehicle components accelerated durability test is introduced. The majority of the fatigue damage are identified and extracted from the characteristic frequency bands in the load spectrum using the 12th order Daubechies wavelet. A compression load spectrum can be achieved by the organization of the extracted damage contribution parts. Taking the powertrain mount load spectrum as an example, the wavelet transform-based and damage retention-based edition method is performed to the lengthy load spectrum. The edited results show that the compression load spectrum based on the wavelet transform edition method has the similar statistical parameters including mean value, root mean square and kurtosis as well as the energy to the original load spectrum. The compression loading spectrum is equivalent to the original one. And wavelet transform-based load spectrum edition method can be used in the accelerated durability test research to other vehicle components.