工程陶瓷崩碎损伤的声发射逾渗特征
Acoustic emission percolation characteristics of edge chipping for engineering ceramics
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摘要: 为研究工程陶瓷崩碎损伤演化过程中的逾渗行为,揭示其损伤机理,以氧化铝陶瓷为研究对象,构建了工程陶瓷崩碎损伤实验系统,建立了基于声发射的逾渗理论模型。通过对崩碎损伤过程中声发射信号分析可得:声发射计数率/能量释放率能实时反映陶瓷崩碎损伤过程中裂纹激活率的逾渗行为;基于声发射累积计数/累积能量的破坏比率反映了损伤累积对材料内部性能的影响,可从损伤积累的角度描述陶瓷崩碎损伤过程中的逾渗行为;声发射持续时间反映了陶瓷崩碎过程中逾渗行为的团簇变化规律。研究结果表明:基于声发射的逾渗理论模型可较好的描述陶瓷崩碎损伤演化过程的逾渗特征。Abstract: In order to study the percolation behavior of engineering ceramics during the fracture process of edge chipping and reveal its damage mechanisms, an edge chipping experimental system based on single indentation is built, and a percolation model based on acoustic emission signal parameters is established. The acoustic emission signal analysis based on percolation theory show that count rate/energy release rate could describe the percolation behavior based on crack activation rate, the failure ratio based on acoustic emission cumulative counts/cumulative energy could reflect the percolation behavior from the point of damage accumulation for ceramics, the parameter of duration could describe the cluster formation of micro-cracks well. The researches confirm that percolation model based on acoustic emission signal parameters can describe percolation behavior of engineering ceramics during the fracture process of edge chipping well.