基于证据理论的载荷谱多域信息融合与加速编辑

MULTI-DOMAIN INFORMATION FUSION OF LOAD SPECTRA AND ACCELERATED EDITING BASED ON DEMPSTER-SHAFER'S THEORY

  • 摘要: 提出了一种基于多域信息融合的随机载荷谱加速编辑方法。载荷谱的能量分布、损伤分布和峰值分布可作为加速耐久性编辑的重要证据源,基于证据理论开展载荷谱多域信息的融合,获得能够对载荷点的保留或删除进行决策的信任函数。以编辑前后载荷谱的压缩比作为目标函数,以信任函数阈值作为设计变量,以统计参数(均方根和峭度系数)误差和损伤保留量作为约束条件,利用遗传算法对融合后信任函数阈值进行优化求解。通过定位超过阈值的载荷点作为基准,采用包络线损伤片段识别法,识别出对损伤贡献较大的载荷片段,实现与原始载荷谱作用效果基本一致的编辑载荷谱的获取。以动力总成后拉杆悬置的服役载荷谱为研究对象,进行了加速耐久性编辑处理。通过对编辑前后载荷谱的相关参数对比,结果表明:所提出的基于多域信息融合的随机载荷谱加速编辑方法,能够在保证编辑前后载荷谱的统计参数误差不超过10%和损伤参量大于95%的前提下,实现载荷谱的编辑前后具有基本相同的加载效果。且与未采用信息融合的方法相比,所得到的编辑载荷谱在统计参数(均方根和峭度系数)的偏差和损伤保留量等方面均表现出优势。

     

    Abstract: A method for accelerated editing of random load spectra based on multi-domain information fusion is proposed. The energy distribution, damage distribution and peak distribution of the load spectra can serve as important sources of evidence for accelerated durability editing. Based on the Dempster-Shafer's evidence theory, the multi-domain information of load spectra is fused to obtain a belief function that can make decisions on whether to retain or delete load points. Taking the compression ratio of the load spectra before and after editing as the objective function, the threshold of the belief function as the design variable, and the errors of statistical parameters (root mean square and kurtosis coefficient) and the damage retention amount as the constraint conditions, the genetic algorithm is used to optimize and solve the threshold of the fused belief function. By taking the load points exceeding the threshold as a benchmark and using the envelope damage segment identification method, the signal segments that contribute more to the damage are identified, so as to obtain an edited load spectrum with basically the same effect as the original load spectrum. Taking the service load spectrum of the rear mount of the powertrain as the object, the accelerated durability editing process is carried out. By comparing the relevant parameters of the load spectra before and after editing, the results show that: the proposed accelerated editing method for random load spectra based on multi-domain information fusion can ensure that the statistical parameter errors of the load spectra before and after editing do not exceed 10% and the damage parameters are greater than 95%. Compared with traditional methods, the obtained edited load spectrum has advantages in terms of the deviations of statistical parameters (root mean square and kurtosis coefficient) and the damage retention amount.

     

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