Numerical analysis on the structural behavior of a non-engaging CFRP bellows coupling for propulsion technology

Fiber reinforced polymers (FRP) are used in a widespread range, for example in aerospace, mobility or wind energy applications due to their excellent quality profile. Moreover, rotating machine elements, which are applied in dynamic processes, require a primarily high stiffness combined with an elastic behavior. Novel FRP components or modern hybrid structures lead to a lower energy consumption of the entire mechanical system. In this respect, a shaft coupling between two shafts depicts an exemplary machine element for a possible application of FRP. This paper deals with the numerical analysis on the structural behavior of a non-engaging bellows coupling made of prepreg-based carbon fiber reinforced polymers (CFRP) for propulsion technology. The presented concept is based on the methodological construction approach for the fulfillment of the compensation and connection functionality. A very high torsional stiffness as well as a certain bending flexibility of the whole coupling geometry is required due to the connection of two torsion-loaded structures. Specific geometrical design variables could be identified with the finite elements method (FEM) and the design of experiments (DoE), which have a significant influence on the structure mechanical behavior of the CFRP bellows coupling. Based on a variable identification scheme according to Shainin, the influence of various geometrical design factors on the structural performance of the CFRP bellows coupling was evaluated.