Integration of Geometry and Analysis for the Study of Leaf Springs in Multibody Applications

Leaf springs are a suspension component of many vehicles including passenger, commercial, and railroad vehicles. Leaf springs may be categorized as uniform-thickness multi-leaf (UTML) springs, which feature several flat leaves, or parabolic leaf springs, which include one or two tapered leaves. UTML springs are usually rated to support more weight and are therefore often installed on heavier commercial vehicles, but they usually result in reduced ride comfort. Parabolic leaf springs, on the other hand, are much lighter in weight and result in a more comfortable ride and are therefore often installed on passenger vehicles. To ensure that leaf springs meet the required design criteria, accurate leaf spring models are crucial. However, the modeling approaches currently used by design engineers often make many simplifying assumptions and may not accurately represent the geometry or distributed inertia of the component. Furthermore, the process of converting solid models to analysis meshes is time-consuming and error-prone, which may lead to mistakes during the conversion process. Therefore, the goal of this thesis is to investigate accurate leaf spring modeling techniques which can be used in the design and validation process in industry. The complex geometry of a leaf spring will be obtained using scanning techniques, and the obtained data will be used to create leaf spring models using different finite elements (FEs). Leaf spring models will be integrated with full MBS vehicle algorithms and the effects of the pre-stress and inter-leaf friction will be demonstrated.