Kyzioł Lesław, Panasiuk Katarzyna, Hajdukiewicz Grzegorz, Dudzik Krzysztof
Faculty of Marine Engineering, Gdynia Maritime University, 81-225 Gdynia, Poland.
Sensors (Basel). 2020 Dec 28;21(1):145. doi: 10.3390/s21010145.
Due to the unique properties of polymer composites, these materials are used in many industries, including shipbuilding (hulls of boats, yachts, motorboats, cutters, ship and cooling doors, pontoons and floats, torpedo tubes and missiles, protective shields, antenna masts, radar shields, and antennas, etc.). Modern measurement methods and tools allow to determine the properties of the composite material, already during its design. The article presents the use of the method of acoustic emission and Kolmogorov-Sinai (K-S) metric entropy to determine the mechanical properties of composites. The tested materials were polyester-glass laminate without additives and with a 10% content of polyester-glass waste. The changes taking place in the composite material during loading were visualized using a piezoelectric sensor used in the acoustic emission method. Thanks to the analysis of the RMS parameter (root mean square of the acoustic emission signal), it is possible to determine the range of stresses at which significant changes occur in the material in terms of its use as a construction material. In the K-S entropy method, an important measuring tool is the extensometer, namely the displacement sensor built into it. The results obtained during the static tensile test with the use of an extensometer allow them to be used to calculate the K-S metric entropy. Many materials, including composite materials, do not have a yield point. In principle, there are no methods for determining the transition of a material from elastic to plastic phase. The authors showed that, with the use of a modern testing machine and very high-quality instrumentation to record measurement data using the Kolmogorov-Sinai (K-S) metric entropy method and the acoustic emission (AE) method, it is possible to determine the material transition from elastic to plastic phase. Determining the yield strength of composite materials is extremely important information when designing a structure.
由于聚合物复合材料具有独特的性能，这些材料被应用于许多行业，包括造船业（船只、游艇、摩托艇、快艇的船体，船舶及冷却门，浮筒和浮子，鱼雷发射管和导弹，防护盾，天线桅杆，雷达屏蔽罩和天线等）。现代测量方法和工具能够在复合材料设计阶段就确定其性能。本文介绍了利用声发射方法和柯尔莫哥洛夫 - 西奈（K-S）度量熵来确定复合材料力学性能的方法。测试材料为不含添加剂的聚酯玻璃层压板以及含有10%聚酯玻璃废料的层压板。在加载过程中复合材料发生的变化通过声发射方法中使用的压电传感器进行可视化。通过对RMS参数（声发射信号的均方根）的分析，可以确定材料作为建筑材料使用时应力发生显著变化的范围。在K-S熵方法中，一个重要的测量工具是引伸计，即内置的位移传感器。在使用引伸计进行静态拉伸试验过程中获得的结果可用于计算K-S度量熵。许多材料，包括复合材料，都没有屈服点。原则上，不存在确定材料从弹性阶段过渡到塑性阶段的方法。作者表明，使用现代测试机和非常高质量的仪器，通过柯尔莫哥洛夫 - 西奈（K-S）度量熵方法和声发射（AE）方法记录测量数据，可以确定材料从弹性阶段到塑性阶段的转变。在设计结构时，确定复合材料的屈服强度是极其重要的信息。
