Carbon fiber-reinforced polymers are widely used in the aerospace industry due to their exceptional weight-specific mechanical properties. However, they are exposed to various thermal threats, ranging from low loads such as solar radiation to extreme loads like lightning strikes. Compared to metallic alternatives, these materials have lower thermal stability. Thus, the investigation of thermo induced degradation mechanisms under different loading scenarios is crucial. This work is divided into three sections: In the first section, various thermal degradation processes are examined to reconstruct the fundamental damage mechanism. This mechanism includes the decomposition of the polymer matrix, the weakening of fiber-matrix adhesion, the formation of structural damage such as delamination, the loss of interlaminar ply adhesion, the depletion of the material and the oxidation of the carbon fibers. In the second section, the influence of various factors on the thermal degradation of fiber composites under one-sided heat load is analyzed. For this purpose, long-lasting, low and short-lasting, high heat fluxes are applied to materials with different compositions, volumes and surface coatings. These impact factors determine the thermo-induced damage distributions along the cross-section and thus the mechanical properties of the material. However, in real loading scenarios, these factors are usually insufficiently known or cannot be fully taken into account. Therefore, an extremely robust and universally applicable model is developed to predict the residual interlaminar shear, compressive, flexural and tensile strength after thermal loading with superior quality, independent of these impact factors. This model thus contributes to ensuring the performance of the material in aviation. In the last section, the heat conduction of the composite material is optimized by adding conductive nanoparticles. Two approaches are pursued: on the one hand, carbon black particles and carbon nanotubes are integrated into the polymer melt, on the other hand, prepreg plies are laminated with buckypapers. Both approaches aim to slow down the thermal degradation in the material and consequently increase safety in aviation. The main goal of this study is to provide a comprehensive understanding into the damage behavior of the fiber composite material under different thermal loading scenarios. This forms the basis for the development of a non-destructive testing method, which should enable a precise assessment of the thermal damage and residual strength of aircraft components.     «

Carbon fiber-reinforced polymers are widely used in the aerospace industry due to their exceptional weight-specific mechanical properties. However, they are exposed to various thermal threats, ranging from low loads such as solar radiation to extreme loads like lightning strikes. Compared to metallic alternatives, these materials have lower thermal stability. Thus, the investigation of thermo induced degradation mechanisms under different loading scenarios is crucial. This work is divided into t...     »