Influence of voids on damage mechanisms in carbon/epoxy composites determined via high resolution computed tomography
Influence of voids on damage mechanisms in carbon/epoxy composites determined via high resolution computed tomography
复制标题
DOI：
10.1016/j.compscitech.2013.11.004
复制
发表时间：
2014-01-10
影响因子：
9.1
通讯作者：
Hepples, W.
中科院分区：
文献类型：
--
作者：
Scott, A. E.;Sinclair, I.;Hepples, W.
多尺度计算机断层扫描 (CT) 技术已用于确定静压复合材料圆周结构的材料结构和损伤机制。声发射传感用于宏观定位负载下高损伤区域，以便为计算机断层扫描提供信息。所得图像可以对空隙、纤维断裂和裂纹进行直接三维分析，与其他间接和/或基于表面的方法相比，结果具有较高的可信度。对加载样品的异位分析显示，纵向缠绕层中存在基体裂纹，而在周向缠绕层中观察到纤维断裂。纵向缠绕层内的基体开裂与层内空隙直接相互作用。圆周缠绕层中的空隙与纤维断裂的相关性不太明显。使用三维镶嵌技术来分析空隙的空间分布并与单纤维断裂位置进行比较。虽然纤维断裂密度和空隙体积分数或空隙尺寸之间不存在一阶相关性，但在空隙和最近的相邻纤维断裂之间发现了明显的相关性，其中紧邻空隙发生的纤维断裂比随机分布的断裂预期多 2.6-5 倍。 (C) 2013 Elsevier Ltd. 保留所有权利。
A multi-scale computed tomography (CT) technique has been used to determine the material structure and damage mechanisms in hydrostatically loaded composite circumferential structures. Acoustic emission sensing was used to locate macroscopically regions of high damage under load to inform the computed tomography. The resultant images allow direct three-dimensional analysis of voids, fibre breaks and cracking, for which a high level of confidence can be placed in the results when compared to other indirect and/or surface-based methods.Ex situ analysis of loaded samples revealed matrix cracking in the longitudinally wound plies, whilst fibre breaks were observed in the circumferentially wound plies. The matrix cracking within the longitudinally wound plies is shown to interact directly with intralaminar voids. The correlation of voids with fibre breaks in the circumferentially wound plies is less distinct. A three-dimensional tessellation technique was used to analyse the spatial distribution of the voids and to compare with single fibre break locations. Whilst there was no first order correlation between fibre break densities and void volume fractions or void dimensions, a distinct correlation was found between voids and nearest neighbouring fibre breaks, where 2.6-5 times more fibre breaks occurred immediately adjacent to a void than would be expected for randomly distributed breaks. (C) 2013 Elsevier Ltd. All rights reserved.