Modeling of the Weave and Wobble Eigenmodes of Motorcycles Using Flexible Multibody Simulation

Abstract Weave and wobble are well known eigenmodes of motorcycles and have been studied by several authors because of their importance to the overall stability and safety of motorcycles. Studies have highlighted the importance of structural flexibility on these eigenmodes. A common approach in multibody simulationfor modeling the flexibility is the lumped stiffness method. It is advantageous for its limited modeling effort and its small impact on computational time. However, it was never demonstrated if this approach leads to sufficient accuracy when simulating the weave and wobble eigenmodes. The present work answers this question by modeling the structural components of a motorcycle with the flexible multibody approach. The most relevant components for the stability of weave and wobble are identified. A comparison with the lumped stiffness approach is also proposed. Moreover, some implementation details concerning models with flexible bodies are discussed.