Intrinsically monitored carbon fiber composites using electrical properties

“本质监测碳纤维复合材料”研究项目旨在研究碳纤维增强塑料的电性能和机械性能之间的相互作用，以达到状态监测的目的。提出了碳纤维复合材料的成分应变和结构损伤均可用电测技术测量的假设。因此，承载材料本身可以用于负载测量，从而导致具有高度材料一致性的感觉功能的集成，而不是专用传感器。弹性元件应变导致形状的变化和压阻效应，从而导致电阻的可逆变化。通过电学路径的不可逆变化，可以观察到纤维的断裂和分层。碳纤维作为传感器的适用性在很大程度上取决于它是否被拉伸。刺激会导致感觉特性的显著降低和分散。因此，在本项目中，首次提出了拉挤作为碳纤维应变传感器的制造技术。拉挤是一种很有前途的应变传感器制造技术，因为它在敏感的活性碳纤维上施加了工艺固有的预应力。其目标是为基于碳纤维的集成应变传感器的生产创造一种连续的工艺。然后将以这种方式生产的传感器集成到玻璃和碳纤维增强塑料中，并测试其可实现的应变测量精度。

The research project "Intrinsically monitored carbon fibre composites" deals with the interaction of electrical and mechanical properties of carbon fibre reinforced plastics for the purpose of condition monitoring. The hypothesis is pursued that both component strains and structural damage in carbon fibre composites can be measured using electrical measurement techniques. Thus, instead of dedicated sensors, the load-bearing material itself can be used for load measurement and thus lead to an integration of sensory functions with high material conformity. Elastic component strains lead to changes in shape and piezoresistive effects leading to a reversible change in the electrical resistance. Fiber cracks and delaminations can be observed by irreversible changes of the electrical paths. The suitability of the carbon fiber as a sensor depends largely on whether it is stretched or not. Ondulations lead to a significant reduction and scattering of the sensory property. In this project, therefore, pultrusion is proposed for the first time as a manufacturing technology for carbon fiber-based strain sensors. Pultrusion is a promising technology for the production of strain sensors due to its process-inherent prestressing on the sensorically active carbon fibers. The goal is to create a continuous process for the production of integrated strain sensors based on carbon fibers. The sensors produced in this way are then integrated into glass and carbon fiber reinforced plastics and tested for their achievable strain measurement accuracy.