Damage tolerant Thin-Ply Carbon Fiber Reinforced Composites with Graphene enhanced Matrix

目标是优化纤维增强聚合物（FRP）的机械性能，其具有薄层结构和纳米颗粒的基体改性，特别是关于对冲击的损伤容忍度。在许多部件中，抵抗自由边缘处材料早期损伤的能力是非常重要的。这种性能的优化可以通过减少层压板的单层厚度来实现。使用这种被称为薄层的技术，在复合层压板的总厚度不变的情况下，微裂纹等损伤的数量可以显著减少。然而，较小的损伤量对裸眼试样的力学性能和抗冲击损伤性能有负面影响，因为其断裂韧性较低。因此，薄层复合材料的极限静强度低于相同厚度的传统复合材料，并表现为脆性破坏。由于冲击损伤缺陷的发展主要受基体主导的力学性能的影响，因此研究薄层板的这些缺点是否可以通过插入纳米颗粒的聚合物改性来弥补。石墨烯纳米颗粒的基体改性是一种很有前途的方法，已经广泛应用于优化传统FRP。制备了具有薄层结构的纤维增强聚合物和石墨烯纳米颗粒改性的基体，并研究了失效机制，厚度和层向以及石墨烯纳米颗粒的影响，以充分挖掘这些有前途的新材料的潜力。

The objective is to optimise the mechanical properties of fibre reinforced polymers (FRP) with a thin-ply laminate structure and a matrix modification with nanoparticles particularly with regard to the damage tolerance against impacts. The resistance against early material damage at free edges is of great importance in many components. An optimisation of this property can be achieved by reducing the single ply thickness of the laminate. With this technology, called thin-ply, the amount of damage, such as microcracking can be significantly reduced at constant total thickness of the composite laminate. However, the smaller amount of damage has negative influence of the mechanical properties of open-hole specimen and with regard to the resistance against impact damage, because of the lower fracture toughness. Thus, the ultimate static strength of thin-ply laminates is lower in comparison to traditional laminates of the same thickness and they show a brittle type of failure. Since the defect development at impact damage is mainly influenced by matrix dominated mechanical properties, it is to be investigated, whether these disadvantages of the thin-ply laminates might be compensated by a polymer modification increasing the fracture toughness with an insertion of nanoparticles. A matrix modification with graphene nanoparticles is here a promising approach that is already applied extensively for optimising traditional FRP. Fibre reinforced polymers with a thin-ply laminate structure and a matrix modification with graphene nanoparticles are to be produced and the failure mechanisms, the influence of ply thickness and layer orientation as well as graphene nanoparticles is to be investigated in order tap the full potential of these promising new materials.