Louda Petr, Sharko Aleksandr, Stepanchikov Dmitry, Sharko Artem
Department of Material Science, Technical University of Liberec, 461 17 Liberec, Czech Republic.
Department of Transport Technology and Mechanical Engineering, Kherson Marine Academy, 73000 Kherson, Ukraine.
Materials (Basel). 2022 May 26;15(11):3791. doi: 10.3390/ma15113791.
Propagation of acoustic emission signals in continuous conjugated media under real-time loading was explored. The results of explored plastic deformation polymer coatings on a metal base using the acoustic emission method with synchronization of deformations and the moments of occurrence of acoustic emission signals are presented. Using the principal component method, the acoustic emission spectra, which make it possible to trace the evolution of deformation transformation processes, were analyzed. Presented the results of theoretical and experimental studies on the separate propagation of acoustic emission vibrations in a polymer coating, a metal base, and their joint combination in the form of multilayer structures. Boundary problems of propagation of acoustic emission signals in the conjugation of continuous media are considered from the standpoint of an elastic continuum and wave representations. The main variables are the force that initiates the appearance of acoustic emission signals and the displacement that determines the propagation of elastic waves. Based on the local rearrangement of the internal structure of conjugated media under conditions of development of deformation processes in the material, the verification of the main theoretical models of energy spectrum acoustic signals in continuous media at the micro-, meso-, and macro-levels was carried out. In this work, we present experimental data on a set of basic acoustic emission characteristics for four-point bending. It is shown that the principal components method reduces the dimension of data while maintaining the least amount of new information. Using the method of principal components to determine the stages of plastic deformation of polymer coatings on a metal base using the acoustic emission method. With the digitalization of acoustic emission signals and noise filtering, new possibilities for isolating a weak signal at the noise level appear even when its amplitude is significantly lower than the noise level. The study results can be used to predict the degree of destruction of two-layer materials under loading.
研究了声发射信号在实时加载下连续共轭介质中的传播。给出了使用声发射方法对金属基底上的塑性变形聚合物涂层进行研究的结果，该方法实现了变形与声发射信号出现时刻的同步。利用主成分分析法对声发射光谱进行了分析，通过该光谱可以追踪变形转变过程的演变。给出了关于声发射振动在聚合物涂层、金属基底中单独传播以及它们以多层结构形式联合组合传播的理论和实验研究结果。从弹性连续体和波动表示的角度考虑了声发射信号在连续介质共轭处传播的边界问题。主要变量是引发声发射信号出现的力和决定弹性波传播的位移。基于材料变形过程发展条件下共轭介质内部结构的局部重排，在微观、细观和宏观层面上对连续介质中能量谱声信号的主要理论模型进行了验证。在这项工作中，我们给出了四点弯曲一组基本声发射特性的实验数据。结果表明，主成分分析法在保持最少新信息的同时降低了数据维度。利用主成分分析法通过声发射方法确定金属基底上聚合物涂层的塑性变形阶段。随着声发射信号的数字化和噪声滤波，即使在微弱信号幅度明显低于噪声水平时，也出现了在噪声水平下分离微弱信号的新可能性。研究结果可用于预测两层材料在加载下的破坏程度。
