基于声发射的木材纤维/高密度聚乙烯复合材料裂纹起裂点表征研究

Guo Yong, Zhu Shiliu, Chen Yuxia, Liu Dian, Li Dagang

School of Forestry and Landscape Architecture, Anhui Agricultural University, Hefei 230036, China.

College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China.

Polymers (Basel). 2019 Apr 17;11(4):701. doi: 10.3390/polym11040701.

The crack initiation point can be regarded as a sign of composite failure and plays a vital role in the evaluation of fracture toughness. Wood-plastic composites (WPCs) are viscoelastic materials and the evaluation of fracture mechanism and toughness has a great significance in their applications. Therefore, we used the acoustic emission (AE) technique to measure the crack initiation point of the WPCs and evaluate their fracture toughness. The results show that the novel AE-based methods were more effective than the conventional standard methods for characterization of the crack initiation point. Using the relationship of cumulative AE events with time and load, the critical failure load was quickly determined, and then the critical stress intensity factor and fracture toughness were calculated. The fracture toughness of the WPCs increased with an increase in the wood fiber content.

裂纹起始点可被视为复合材料失效的标志，在断裂韧性评估中起着至关重要的作用。木塑复合材料（WPCs）是粘弹性材料，其断裂机理和韧性评估在其应用中具有重要意义。因此，我们采用声发射（AE）技术来测量木塑复合材料的裂纹起始点并评估其断裂韧性。结果表明，基于声发射的新方法在表征裂纹起始点方面比传统标准方法更有效。利用累积声发射事件与时间和载荷的关系，快速确定了临界失效载荷，进而计算出临界应力强度因子和断裂韧性。木塑复合材料的断裂韧性随木纤维含量的增加而提高。