Effect of off-axis angle on low-velocity impact and compression after impact damage mechanisms of 3D woven composites

• Published in: Materials & design 2020-07, Vol.192, p.108672, Article 108672
• Main Authors: Zhang, Diantang, Gu, Yuanhui, Zhang, Zhongwei, Jia, Minghao, Yue, Songlin, Li, Gan
• Format: Article
• Language: English
• Subjects: 3-Dimensional reinforcement; Compression after impact; Damage mechanism; Impact; Mechanical properties; Micro-CT analysis
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2020.108672

This paper presents the influence of the off-axis angles on the low-velocity impact (LVI) and compression after impact (CAI) damage mechanism of three-dimensional (3D) woven carbon/epoxy composites. Three kind of samples with different angles, 0°, 30° and 45°, of the weft and warp yarn orientation were experimentally tested using the drop weight LVI and quasi-static CAI equipment. X-ray micro-computed tomography (Micro-CT) techniques were used to identify the impact damage volumes, damage distribution and damage modes of 3D woven composites. Results indicated that the off-axis angles have significant effects on the LVI and CAI mechanical behavior and final failure mechanisms. Furthermore, Micro-CT revealed that off-axis samples exhibit more damage volumes and out-of-plane deformation. More importantly, the ultimate CAI strength of all the samples are largely governed by the global buckling. However, the formation of buckling damage in 0° samples runs from one edge of the specimen to the other side, whereas that in 30° and 45° samples mainly occur along the weft direction. [Display omitted] •We examine the LVI and CAI mechanical behavior of 3D woven fabric composites with different off-axis angle.•Micro-CT is used to identify the internal damage of 3D woven composites subjected to LVI loading.•Off-axis samples exhibit higher damage volumes than on-axis ones for any impact energy tested.•The ultimate CAI strength of all the samples are largely governed by the global buckling.