Becker Christian, Hausmann Joachim, Krummenacker Janna, Motsch-Eichmann Nicole
Leibniz-Institut für Verbundwerkstoffe GmbH, 67663 Kaiserslautern, Germany.
Materials (Basel). 2023 Jul 5;16(13):4842. doi: 10.3390/ma16134842.
This paper presents the first results on the characterisation of the damage behaviour of recycled carbon fibre (rCF) rovings manufactured into unidirectionally (UD) reinforced plates. In the first step, the mechanical properties of several material combinations were determined by mechanical tests (tensile, flexural, compression). This proves the usability of the material for load-bearing structures. For example, a tensile modulus of up to 80 GPa and a tensile strength of 800 MPa were measured. Subsequently, the fracture surface was analysed by scanning electron microscopy (SEM) to characterise the fibre-matrix adhesion and to obtain first indications of possible failure mechanisms. Despite the high mechanical properties, poor fibre-matrix adhesion was found for all matrix systems. In situ X-ray microscopy tests were then performed on smaller specimens under predefined load levels as transverse tensile and bending tests. The results provide further predictions of the failure behaviour and can be compared to the previous test results. The three-dimensional scan reconstruction results were used to visualise the failure behaviour of the staple fibres in order to detect fibre pull-out and fibre or inter-fibre failure and to draw initial conclusions about the damage behaviour in comparison to conventional fibre composites. In particular, a benign failure behaviour in the transverse tensile test was demonstrated with this procedure. In addition, first concepts and tests for the integration of AE analysis into the in situ setup of the X-ray microscope are presented.
本文展示了关于制成单向（UD）增强板的回收碳纤维（rCF）粗纱损伤行为表征的首批结果。第一步，通过力学测试（拉伸、弯曲、压缩）确定了几种材料组合的力学性能。这证明了该材料在承载结构中的可用性。例如，测得的拉伸模量高达80 GPa，拉伸强度为800 MPa。随后，通过扫描电子显微镜（SEM）分析断裂表面，以表征纤维与基体的粘附情况，并获得可能的失效机制的初步迹象。尽管力学性能很高，但所有基体系统都存在纤维与基体粘附不良的情况。然后，在预定义的载荷水平下，对较小的试样进行原位X射线显微镜测试，作为横向拉伸和弯曲试验。结果提供了对失效行为的进一步预测，并可与先前的测试结果进行比较。三维扫描重建结果用于可视化短纤维的失效行为，以便检测纤维拔出以及纤维或纤维间的失效，并与传统纤维复合材料相比，对损伤行为得出初步结论。特别是，通过该程序证明了横向拉伸试验中的良性失效行为。此外，还介绍了将声发射分析集成到X射线显微镜原位设置中的初步概念和测试。
