Time-frequency signature investigation of operational shock-induced slider transient dynamics and damage by enhanced ensemble noise-reconstructed EMD
Time-frequency signature investigation of operational shock-induced slider transient dynamics and damage by enhanced ensemble noise-reconstructed EMD
复制标题
通过增强系综噪声重构 EMD 对运行冲击引起的滑块瞬态动力学和损伤进行时频特征研究
DOI：
10.1016/j.triboint.2019.06.004
复制
发表时间：
2019
影响因子：
6.2
通讯作者：
Shaowen Chen
中科院分区：
文献类型：
--
作者：
Yu Wang;Jing Yuan;Ang Yang;Shaowen Chen
硬盘驱动器 (HDD) 存储密度的不断增加（例如目前为 1 Tb/in2）需要将磁头和磁盘之间的物理间隙减小到埃级。在如此超薄的间隙下，硬盘中突然发生的震动可能会因意外冲击而损坏磁头盘接口。运行冲击试验及其动力学分析中涉及的损伤机制至关重要，而此前的研究很少。此外，由于受到严重噪声污染的局部非平稳动态特性较弱，对滑块/磁盘相互作用的有意义的解释很难解决。为了揭示损伤机制，本文设计并进行了冲击引起的滑块与磁盘相互作用的实验研究，并提出了基于增强系综噪声重构经验模态分解（EMD）的时频方法来识别冲击引起的滑块瞬态动力学。在此，开发了邻近系数去噪和极小极大阈值来增强与弱冲击相关的特征。同时引入两种时频特征指标分别描述一次突发冲击的损伤和整个冲击过程的损伤。结果表明，该方法能够成功识别冲击过程中滑块与磁盘相互作用的主要模式并评估其损伤程度，与扫描电子显微镜（SEM）检查的滑块损伤程度吻合。
A continuous increase of the storage density of a hard disk drive (HDD), e.g., currently 1 Tb/in2, requires the physical clearance between magnetic head and disk to be reduced to angstrom level. At such ultra-thin clearance, a sudden shock occurred in HDD may destroy the head-disk interface caused by the unexpected impacts. The damage mechanisms involving in the operational shock testing and its dynamic analysis are crucial, which are few studied previously. Moreover, the meaningful interpretation to the slider/disk interactions is challenging to be addressed due to the weak local nonstationary dynamic characteristics contaminated by heavy noise. To reveal the damage mechanisms, this paper designed and conducted the experimental studies of shock-induced slider-disk interactions, and proposed enhanced ensemble noise-reconstructed empirical mode decomposition (EMD) based time-frequency method to identify the shock-induced slider transient dynamics. Hereinto, the neighboring coefficient denoising and minimax threshold are developed to enhance the weak shock-related signatures. Meanwhile, two kinds of time-frequency signature indicators are introduced to respectively describe the damage of one sudden shock and that of the whole shock process. The results show that the method can successfully identify the main modes of slider-disk interactions during shocking process and evaluate the damage degree, well agreed with the slider damage inspected by scanning electron microscope (SEM).