The present experimental work investigates the response of woven glass fabric reinforced polyamide 6.6/6 subjected to drop weight impact loading. The main objective is the development and the introduction of a new experimental procedure/approach, based on different complementary detection techniques, that aims at investigating the damage induced by impact loading in thermoplastic woven fabric composites. The developed approach is intended to be generalized to other types of composite materials. The main idea is to assess all the experimental results obtained through the developed procedure with a direct investigation method. The latter consists in the Permanent Indentation (PI) measurement providing an indicator of the damage criticality in the composite sample. To this end, several non-destructive testing methods are carried-out and their experimental findings are analyzed and cross-linked. The identification of the different damage mechanisms, caused by the drop weight impact, is performed using X-Ray micro-computed tomography (mCT). C-scan ultrasonic investigation is conducted according to two types: transmission and reflection for the detection of the impact damage and the identification of the induced degradation area. B-scan imaging are then obtained through specific post-processing of the impacted surface to extract the permanent indentation (PI). The latter is validated through surface flatness measurement using the highly resolved 3D optical profilometry. The correlation between the X-Ray tomography results and the permanent indentation measurement is then established. It correlates the PI level with the damage mechanisms of a barely visible impact damage (BVID) in woven glass reinforced polyamide 6.6/6 composite.

中文翻译：

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使用超声波成像、X 射线断层扫描和光学轮廓测定法检测和评估编织玻璃纤维增​​强聚酰胺 6.6/6 复合材料中几乎不可见的冲击损伤

目前的实验工作研究了玻璃织物增强聚酰胺 6.6/6 受到落锤冲击载荷的响应。主要目标是开发和引入一种新的实验程序/方法，基于不同的互补检测技术，旨在研究热塑性机织织物复合材料中冲击载荷引起的损伤。开发的方法旨在推广到其他类型的复合材料。主要思想是使用直接调查方法评估通过开发程序获得的所有实验结果。后者包括永久压痕 (PI) 测量，提供复合样品中损坏临界的指标。为此，进行了几种无损检测方法，并对它们的实验结果进行了分析和交联。使用 X 射线显微计算机断层扫描 (mCT) 识别由落锤冲击引起的不同损坏机制。C 扫描超声调查根据两种类型进行：透射和反射，用于检测冲击损伤和识别诱导退化区域。然后通过对撞击表面的特定后处理获得 B 扫描成像，以提取永久压痕 (PI)。后者通过使用高分辨率 3D 光学轮廓测量法的表面平整度测量进行验证。然后建立 X 射线断层扫描结果和永久压痕测量之间的相关性。