摘要针对碳纤维树脂基复合材料结构修理，研究了一种高分辨率超声（High-resolution ultrasonic，HU）方法，构建了 HU 检测系统，设计制备了复合材料结构修理试件，研究了修理区 HU 信号时域行为，开展了系列复合材料结构修理 HU 断面可视化成像试验研究，试验结果表明，利用 HU 方法，回波信号的质量、时域可分辨性均明显优于常规超声方法；对于 4.5mm 厚碳纤维复合材料结构修理试件，基于 HU 信号估测的特征尺寸评估结果与设计值接近 0 偏差；利用 HU 断面成像及其图像灰度分布规律，可以非常直观地揭示未修理区、修理区形貌、修理连接界面、修理区缺陷、修理区局部树脂、内部微结构等修理行为细节，可以非常直观和清晰地检出复合材料结构修理区近表面一层和近底面一层及其中间深度位置的 φ 6mm 缺陷和局部树脂；成像分辨率可达单个复合材料铺层厚度（约 0.125mm）。从而为复合材料结构修理提供了一种具有很好的实际检测应用效果的可视化检测与评估方法。
Abstract：The recovery of composite structure using performance is closely related to the repair quality. Repair quality is associated with defects in repair area. Complex repair behavior and conditions increase the difficulty and uncertainty in non-destructive testing and evaluation (NDT & E) of composite repair. A high-resolution ultrasonic (HU) technique was proposed to characterize carbon-fiber composite repair behaviors and detect defects induced in repair zones. A HU detection system was constructed. The composite repair specimen was manufactured. The time-domain behaviors of the HU signals in repaired area were studied. A series HU experiments were carried out to the repaired specimen using HU cross-sectional imaging technique. The experimental results show that the quality and time-domain resolution of HU echo signals are obviously better than conventional ultrasonic method; the estimated thickness based on the HU signals is close to 0 deviation from its design value for a 4.5mm thick carbon-fiber composite repaired specimen; the detail repair behaviors, such as repaired area, repaired area morphology, repaired bonding interfaces topography, defects and local resin zones in repaired area, internal microstructures, are very clear and intuitively revealed using the HU cross-sectional imaging and image grayscale distributions; the φ 6mm defects located at near the specimen surface and bottom layers and middle depth are detected clearly and intuitively; the imaging resolution is up to the thickness of a single ply (~0.125mm). Thus, it provides a very effective and powerful detection and evaluation for composite repairs, and good practical application has been obtained.
2021, 
