Topology optimization with the redesigned suspension system of the internal combustion vehicle converted to an electrical vehicle

Abstract In this paper, the topology optimization of lower wishbone for a passenger car which is the converted of an internal combustion engine vehicle to an electrical vehicle was presented. On the other hand, the need to study on a suspension system arose for electrical car that was redesigned. In study, topology optimization of the structural design of the lower wishbone to be used in the front suspension was carried out by Finite Element Analysis (FEA) Method. For this purpose, firstly, the suspension spring curves and damper curves that will improve the handling, ride and comfort behaviour of the vehicle were determined, suspension system was modelled with the Multi Body Dynamics (MBD) approach. Hardpoints is necessary for vehicle dynamics and that is also an input for FEA were obtained from new suspension system via MBD analysis. In the second step, The preliminary design of the lower wishbone was created, taking into account together with the positions of the wheel drive shaft, suspension spring and brake system structural elements according to hardpoints. After designing the structure suitable for the joint types, initial design was studied on the remaining region that is for weight reduction region except the joint connection surfaces. Then, topology optimization was applied to the preliminary design for the selected load types that is come from MBD analysis. Thus, the excess volume on the preliminary design was determined for each load type. In the last stage, the results of topology optimization analysis were evaluated to reach out target weight and the producible design of the wishbone was made. Finally, Finite Element Analysis were applied to the final design for validation purposes within topology optimization work was done with the forces coming from Multi Body Dynamics. After statically solved Finite Element Analysis, a modal neutral file(.mnf) was created via FEA solver and was integrated to Adams Car as a flexbody. Flexbody was attahced to the other parts which are rigid bodies like nuckle according to Multi Body Dynamics approach. Dynamics durability cases was carried out via Adams Car. Stress results was compared to FEA results and evaluated depends on yield stress. Study results shows that the new design is lighter and competitive design and also safe in dynamics analysis for redesigned passenger car.