In-situ measurements of fracture toughness properties in composite laminates
In-situ measurements of fracture toughness properties in composite laminates
复制标题
复合材料层压板断裂韧性的现场测量
DOI：
10.1016/j.matdes.2016.01.008
复制
发表时间：
2016
影响因子：
8.4
通讯作者：
Brian Shonkwiler
中科院分区：
文献类型：
--
作者：
Y. Nikishkov;G. Seon;A. Makeev;Brian Shonkwiler
复合材料层合板中基体失效的预测可以使用基于材料强度和断裂韧性的计算方法来完成。由于复合材料变形和失效机制的复杂性，工程理论和失效准则使用由当前标准实验方法产生的材料特性，可能导致预测结构强度和疲劳特性的准确性差。在这项工作中，使用标准试验方法测量的断裂韧性性能的适用性进行了研究。定制的X射线计算机断层扫描系统配备50 kN轴向力能力集成载荷框架，可在载荷下进行全扫描，用于复合材料双悬臂梁试样和开孔拉伸试样中裂纹几何形状的精确3D原位测量。这些实验被用来确定模式I和模式II断裂韧性的基础上，从断层扫描测量传输的模型的有限元分析。虽然测得的层间模式I断裂韧性是在良好的协议与标准测试，intralaminar模式II断裂韧性取决于裂纹长度。
Prediction of matrix failure in composite laminates can be accomplished using computational methods based on material strength and fracture toughness. Engineering theories and failure criteria, which use such material properties generated by current standard experimental methods, may result in poor accuracy of predicting structural strength and fatigue characteristics due to complexity of deformation and failure mechanisms in composites. In this work the applicability of fracture toughness properties measured using standard test methods is investigated. A customized X-ray Computed Tomography system with a 50 kN axial force capacity integrated load frame, enabling full scanning under load, is utilized for accurate 3D in-situ measurements of crack geometry in composite Double Cantilever Beam specimens and Open Hole Tension specimens. These experiments are used to determine Mode I and Mode II fracture toughness based on finite element analysis of models transferred from the tomographic measurements. While measured interlaminar Mode I fracture toughness is in good agreement with standard tests, intralaminar Mode II fracture toughness is shown to depend on crack length.