Influence of matrix properties on fatigue behavior of fiber reinforced polymers

热塑性纤维增强复合材料在许多运输领域的应用越来越广泛。与普通热固性材料相比，热塑性基体材料具有更高的延展性和韧性。这些优越的性能导致了复合材料成分对层压板疲劳性能影响的问题。基体性能影响着载荷循环直至失效以及在一定寿命下的变形行为。建立了热固性基体材料在层状或层状水平上的实验参数化失效模型。一个相关的损伤模型揭示了直至失效的周期和整个寿命期间的变形行为。由于纤维和基体的各向异性和微观不均匀性，导致连续纤维增强聚合物的疲劳行为与平均应力和载荷方向有很强的依赖性。通过实验确定的描述揭示了材料系统对外部载荷的整体响应及其方向和顺序。问题是，预测的精度是由实验努力决定的，每一个组成性质的变化都需要新的实验表征。复合材料的整体响应是由基体、纤维和纤维-基体界面的微观行为决定的。新的纤维-基体组合以及疲劳行为方面的新特性需要对成分的影响有深刻的理解。因此，该项目的目的是在微观水平上对纤维-聚合物复合材料的力学性能和疲劳行为的相互作用产生基本的和系统的理解和描述。通过辐照诱导交联对基体材料的性能进行了系统的改性，并通过实验和模型研究了辐照诱导交联对复合材料疲劳性能的影响。将使用允许分离影响因素的示例材料系统。

Fiber reinforced composite materials with thermoplastic matrix are used increasingly in many transport applications. Thermoplastic matrix materials offer higher ductility and toughness compared to common thermoset systems. These superior properties lead to the question of the influence of the composite constituents on the fatigue properties of a laminate. The matrix properties are influencing the load cycles until failure as well as the deformation behavior at a certain life time. Established thermoset matrix material reveal on laminate or lamina level experimentally parameterized failure models. An associated damage model reveals the cycles until failure and the deformation behavior over the life time. Anisotropy along with microscopic inhomogeneity due to fiber and matrix lead to strong dependency of the fatigue behavior of continuous fiber reinforced polymers to mean stress and load direction. By this scheme experimentally determined description reveals the global response of the material system on external loads and their direction and sequence. Problem is that the precision of prediction is determined by experimental effort and each change of constituent properties requires new experimental characterization. The behavior of matrix, fibers and fiber-matrix interface on microscopic level is responsible for the global response of the composite material. New fiber-matrix combinations and thus new properties regarding fatigue behavior require profound understanding of the influence of the constituents. Aim of the project is therefore generation of basic and systematic understanding and description of the interaction of mechanical matrix properties and the fatigue behavior of fiber-polymer composites on microscopic level. By irradiation induced crosslinking the properties of the matrix material are modified systematically and their influence on the fatigue properties of the composite material is investigated experimentally and with the aid of models. Exemplary material systems will be used which allow separation of influencing factors.