RTM复合材料中分层缺陷的超声表征及量化分析

ULTRASONIC CHARACTERIZATION AND QUANTITATIVE ANALYSIS FOR DELAMINATION IN RTM COMPOSITES

以ZT7H/QY8911碳纤维增强树脂基RTM工艺成型复合材料为研究对象,通过预埋单层聚四氟乙烯薄膜(PTFE)模拟不同尺寸(φ=3 mm,6 mm,10 mm)和不同深度(近上表面、中间深度、近下表明)的分层缺陷,制备了RTM复合材料超声检测试样。基于水浸式超声反射法对缺陷进行超声A-Scan、B-Scan和C-Scan检测表征,并对检测结果进行量化分析。结果表明:超声反射法对RTM复合材料层压板中分层缺陷具有定性、定量检测能力,超声A-Scan检测信号中幅值、相位、时域渡越等特征量与缺陷的尺寸、深度、性质等具有相关性,超声B-Scan检测可以对缺陷深度进行表征,超声C-Scan可以对缺陷尺寸进行表征,深度方向检测分辨率达1个铺层厚度,缺陷尺寸的检测偏差≤1.0 mm。

Regarding ZT7 H/QY8911 carbon fiber reinforced resin matrix composites as research object,this paper prepared specimens using resin transfer molding processes(RTM)with simulated delamination by imbedding polytetrafluoroethylene(PTFE)film with different diameters(φ=3 mm,6 mm,10 mm)and different depth(near-upper-surface,mid-depth and near-lower-surface).Delamination was visually detected and quantitatively analyzed by ultrasonic A-Scan,B-Scan and C-Scan based on water-immersed ultrasonic pulse-echo reflection method.The result shows that the ultrasonic pulse-echo reflection method possesses qualitative and quantitative testing capacity for detecting delamination in RTM composite.The amplitude,phase and transit time of ultrasonic A-Scan signal have correlations with the size,depth and property of delamination.Ultrasonic B-Scan can characterize the defect depth as images with depth detection resolution up to one-ply thickness,while ultrasonic C-Scan can characterize the defect size as images with size detection deviation≤1.0 mm.