Different configurations of hybrid laminates exist, containing e.g. steel or aluminum combined with glass or carbon fibers in a thermoset or thermoplastic matrix, enabling many possibilities regarding customizability at high specific strength. Hybrid laminates composed of aluminum and carbon-fiber-reinforced thermoplastic layers lead to high specific strength while offering good formability and recyclability. But not just the materials determine the performance of the hybrid laminate, also the interfacial bonding is an important factor to consider especially regarding fatigue behavior.
In this study, the fatigue behavior of hot-pressed thermoplastic hybrid laminates is investigated with regard to different metal surface treatments, e.g. mechanical blasting, anodizing, chemical pickling, adhesion promoter. The investigated fiber metal laminate with a 2/1-layer structure is made of AA6082 aluminum alloy and a graded structure of glass- and carbon-fiber-reinforced polyamide 6. For fatigue investigations, a short-time procedure that combines instrumented multiple and constant amplitude tests is applied to gather in a resource-efficient way information about the fatigue behavior in the LCF- and HCF-regime. To obtain detailed insights into the damage mechanisms present at damage initiation and propagation, digital image correlation and thermography are applied in addition to hysteresis measurement methods. Results show that with the used measuring technologies it is possible to distinguish between the fatigue-induced damage mechanisms and damage propagation of the different surface treated laminates for correlation of fatigue performance and behavior.