纤维复合材料分层缺陷演化声发射行为

Acoustic emission behavior of defect evolution of fiber composites embedded with delamination

对含内置分层缺陷的玻璃纤维复合材料进行3点弯曲实验,并利用声发射实时监测其破坏过程,获得复合材料弯曲损伤的力学性能、破坏特性和声发射响应行为.实验研究表明:玻璃纤维复合材料试件加载过程中载荷与挠度曲线呈非线性关系,加载破坏过程中伴随着基体开裂、纤维断裂等损伤模式.试件的失效载荷随内置分层缺陷面积的增大而减小,含分层复合材料试件声发射撞击累积数和相对能量高于无缺陷试件.纤维复合材料的分层缺陷演化及其破坏行为与对应声发射信号幅值、撞击累积数、相对能量等特征参数具有一定的相关性.

In order to achieve the mechanical properties of bending damage,failure characteristics and acoustic emission（AE）response behavior of glass fiber composites with delamination,three-point bending tests and real-time AE monitoring of glass fiber composites were conducted.Experimental results showed that the relationship between load and deflection of glass fiber composites with delamination was non-linear during the loading process.Damage model such as matrix cracking and fiber fracture could be occurred in the process of damage and failure.As the area of internal delamination defect increased,the failure load of the specimens decreased.The AE cumulative hits and relative energy of composite specimens with delamination were higher than those of composite specimen without delamination defect.Delamination defects evolution and failure behaviors of fiber composites were correlated with the corresponding AE characteristic parameter such as amplitude,cumulative hits,relative energy.