大厚度复合材料制件(内埋金属)的超声检测分析

Ultrasonic-Destructive Testing Analysis on Large-Thickness Carbon Fiber Reinforced Composites Embedded With Metal Components

采用超声波无损检测及金相试验方法研究了内埋金属件的大厚度复合材料实心部位的微观结构,发现采取0o纤维在金属件周围进行缠绕铺层时容易引起超声波的衰减,分析了超声波衰减的机理,首先预浸料中夹杂微小气泡引起孔隙率较低,形成了复合材料内部的疏松缺陷;其次由固化过程时内应力引起的微裂纹,导致超声波信号发生衰减;另外,纤维屈曲或局部树脂分布不均匀对超声波也有一定影响。

In this article,micro-scale structures of a solid part of large-thickness composites embedded with a metal adapter were studied through ultrasonic non-destructive testing and metallographic microscopy. Decay of ultrasonic intensity was observed when the metal adapter was wrapped around by 0 degree unidirectional carbon fibers reinforced prepregs. Mechanisms for the ultrasonic decay were analyzed. First,it was micro-scale air bubbles included in prepregs that caused high porosity and formed internal looseness in composites. Second,micro-cracks caused by inner stress during the curing cycle were found responsible for ultrasonic decay. Third,fiber buckling deformation and localized resin also had effects on ultrasonic waves.