Abstract This paper focuses on the experimental high temperature fatigue of Carbon/polyimide 8-harness satin woven composite materials. Traction-traction (R = 0.1) fatigue tests at 250 °C are carried out on Carbon/polyimide [45]6 8-harness satin woven composites under three different environments (air, 2 bar N2, 2 bar O2). Part I is specifically devoted to image based damage characterization by employment of Digital Image Correlation (DIC) and Micro-Computed Tomography (µ-CT) techniques. For the used samples, intra tow matrix cracks along fibres on the external plies are the first damage form at the ply-scale. Damage evolution on the sample surface can be followed during the test (in situ) by using 2D DIC. Moreover, fatigue tests are periodically interrupted to perform µ-CT scans to characterize and quantify the damage in the volume of the samples. The obtained results prove that the damage assessment methods presented in this work are suitable for environmentally-assisted fatigue tests on composite materials.

中文翻译：

---

碳/聚酰亚胺 8 线束缎纹编织复合材料的高温疲劳。第一部分：数字图像相关和微计算机断层扫描损伤表征

摘要 本文重点研究了碳/聚酰亚胺8线缎纹编织复合材料的高温疲劳试验。在三种不同环境（空气、2 bar N2、2 bar O2）下对碳/聚酰亚胺 [45]6 8 线束缎纹编织复合材料进行了 250 °C 的牵引-牵引 (R = 0.1) 疲劳测试。第一部分专门介绍通过使用数字图像相关 (DIC) 和微计算机断层扫描 (μ-CT) 技术进行基于图像的损伤表征。对于使用过的样品，外部层上沿纤维的丝束内基体裂纹是层级的第一种损伤形式。通过使用 2D DIC，可以在测试（原位）期间跟踪样品表面的损伤演变。此外，疲劳测试会定期中断以执行 µ-CT 扫描，以表征和量化样品体积中的损坏。