Design of fiber composite aerospace structures under vibration loads

As a pragmatic conclusion it can be stated that the vibration behavior of components and structures made out of fiber composites is not that different to that of other types of structures or materials, provided the fiber composite material and the structure are well designed. Nevertheless, the higher design degrees of freedom of fiber composites compared to metal structures have positive effects, such as a greater possibility for design parameter tailoring. This includes a beneficial use of possible anisotropy or bending-twisting and other coupling effects, which can be realized in fiber composite structures. Of course, the low material density and relatively high stiffness are beneficial properties for obtaining a correct design under vibration loads. This together with other benefits, such as lower fatigue or higher durability, resulting in less maintenance effort are features which help to keep life cycle cost within limits and usually lower than those for metal structures. Further progress of fiber-reinforced materials and their behavior in components, structures, and systems will not only be achieved by improved fibers, but also by better matrix material. This, for example, holds for better temperature or impact damage resistance, and also for higher stiffness and strength. In some of the design cases discussed above, the variation of the outer shape of components to better adapt to different operational conditions are further areas of investigations. In such shape morphing structures, a quite flexible polymer matrix is frequently used. Design concepts are then needed to relatively easily modify the shape in order to....