Development of optimized vehicles/structures/body for last mile delivery vehicles

The goal of this thesis is to design, optimize and develop two archetypes for new last mile delivery vehicles . Each archetype is studied for two different commercial vehicle dimensions: one for a medium size commercial vehicle, the other for a large size commercial vehicle. At first, the design guidelines are presented to define the vehicles constrains and charachteristics. The main parameters fixed are: the vehicles dimensions, the underframe structures, and the propulsion system: electric powertrain. After the definition of the design guidelines, the archetype models are designed with a CAD software. In this phase, the spaces occupied by the components are evaluated qualitatively. At the same time the possible interferences between parts are controlled. These problems are solved modifying the design of the archetypes. These modifications needs always to take into account the structural mechanics feasibility. Additionally, the battery pack structure and the in wheel-motors are integrated in the CAD model, evaluating their feasibility in terms of space available and funcionality. As next step, the archetypes are analysed in FEM enviroment. The archetypes are reproduced in 1D models. On this models are studied the static analysis under two load cases: tosional case and bending case. Also the dynamic analysis deformation is performed through the modal analysis. Then a detailed parametrical analysis is performed. The main parameters of the archetype models are changed to evaluate their influence in terms of stiffness and mass. Successively, the battery pack structures are inserted in the 1D archetype models. The battery pack influence is studied in terms of stiffness and mass. Also, the battery pack structure parameters are changed to evaluate their behaviour in the model. The last part of the Numerical Analysis introduces the spring links between chassis and battery pack structure, inside the archetype models. Here the difference between rigid and spring link is analysed. Then, the spring link parameters variation is evaluated to understand their influence in the archetype models. After the numerical analysis, the most important results of this study are highligthed and summarized. From the results, the main conclusions of this thesis are extrapolated, verifying if the goal of this thesis is accomplished.