复合材料随机渐进失效分析与声发射监测

结合随机渐进失效分析方法和声发射监测对复合材料单向拉伸试件进行损伤分析。结果表明: 随机渐进失效方法能很好地反映复合材料失效的随机性和渐进性特征。受载初期, 复合材料失效的随机性特征明显, 在整个试件内均有失效产生。随着载荷的增加, 损伤不断累积, "随机临界核"形成, 复合材料很快失效, 且一旦有失效产生, 纤维断裂数的增加与声发射事件数的累积具有很好的一致性。比较基体开裂和界面脱粘对复合材料拉伸性能的影响: 界面脱粘比基体开裂更容易导致复合材料拉伸性能的下降, 当不存在基体开裂和界面脱粘时, 纤维断裂呈现"集簇"特征, 复合材料断裂的脆性特征较为明显。 

Stochastic progressive failure analysis and acoustic emission monitoring of composites

Damage analysis of axial tension specimen was implemented by stochastic progressive failure analysis and acoustic emission (AE) monitoring.The results show that the stochastic progressive failure analysis characteres failure of composite materials well. In the early load stage, the stochastic character of composite failure is apparent, and the failure occurs in the whole specimen. With the load increasing, damage accumulates, "stochastical critical nuclei" emerges and the composite fails completely and quickly.Once there is failure happens, fiber breakage number is positive correlative with AE events.The effect of matrix crack and interface debonding on the composites was also compared and it is found that interface debonding affects tensile strength drop of the composite more severely than matrix crack, if matrix crack and interface debonding are not taken into consideration, clustering characteristics of fiber fracture appears and the composite fails in brittle manner.