Rotordynamics Continuum Finite Element Formulations from a Structural and Multibody Dynamics Perspective

As industries strive for enhanced reliability and efficiency in product optimization, virtual prototyping has gained prominence over its physical counterpart. Advanced engineering simulation tools have thus become essential for addressing the complexities of today’s technology-driven world. The field of rotordynamics plays a critical role in the design and analysis of rotating machinery as they are widely found in various engineering devices for, e.g., energy transmission. Over the years, numerous techniques have been developed to capture the dynamic behavior of rotors. Among these, continuum finite element formulations have emerged as powerful and generic tools. Nevertheless, rotordynamics analysts often rely on simple models based on beam and rigid elements. Moreover, a variety of different formulations and implementations in commercial software exist, but their relationship to one another is oftentimes not clear. This chapter, therefore, presents an overview of rotordynamics finite element formulations based on continuum elements for generic geometries from a structural and multibody dynamics perspective. A derivation of the equations of motion for rotordynamic analyses according to a nodal-based floating frame of reference formulation is provided. Throughout the contribution, emphasis is placed on the comparison and evaluation of different modeling techniques and solution strategies, especially with respect to standard FE commercial software approaches. The discussion includes modal and steady-state analyses.