Metodology for Dynamic Simulation of a Variable Valve Actuation System in High Performance Motorcycle Engines

This thesis presents the development of a dynamic simulation model using GT-Suite to replicate the behavior of the Cylinder Deactivation (CDA) system implemented on the Ducati Multistrada V4 engine. The initial section outlines the engine’s architecture, key components, and the operating principles of the CDA system. The second section details the modeling strategy adopted within GT-Suite, including the representation of all relevant engine components and the methodology used to synchronize the CAD model with the engine’s mechanical configuration. A significant focus is placed on the phasing process to ensure accurate simulation fidelity. The third section explores the Finite Element Method (FEM) analysis applied to the actuator mechanism, with particular emphasis on the stiffness interaction between the shifting camshaft and the actuator pin. Multiple approaches are evaluated, and the most effective strategy involves decomposing the actuator into individual contact interfaces and calculating stiffness across the contact chain. The final section presents the simulation results and assesses the robustness of the model. Findings indicate that actuator modeling is highly sensitive to contact damping, viscous damping, and contact stiffness parameters. However, limitations persist in accurately capturing the effects of mechanical clearances. Future work will focus on validating the physical coefficients through experimental testing to enhance model accuracy and predictive capability.