A Spline-Based Analytical Model for the Design of an Automotive Anti-Roll Bar

The new corner-based architecture of electrified road vehicles requires a redesign of vehicle suspension components. The design protocol must satisfy the target parameters derived from dynamics requirements. The roll stiffness of the anti-roll bar is a crucial parameter for the handling performance of a vehicle. During the development of a new suspension, the design of the anti-roll bar needs to be modified. To this aim, two-dimensional beam theory models can quickly provide a preliminary design of this component. However, the simplified models might be inaccurate due to the three-dimensional and complex shapes of the bars. The present study aims to overcome this limitation. An analytical beam model based on the spline description of the bar has been developed, which is accurate even for complex geometries of the bars. Assuming a hollow and closed circular cross-section, the model returns the average diameter and the radial thickness needed to achieve the stiffness performance. Three different approaches for the thickness have been analyzed by assuming: (I) a prescribed thickness, (II) a prescribed global mass, and (III) a prescribed maximum value of stress. The first two methods present a uniform thickness along the bar, whereas, in the third one, the thickness varies to obtain the lightest solution. This latter method can be modified to ensure a feasible minimum thickness. Finally, a full-factorial design of the experiments algorithm has been developed to reduce the stress by varying the position of the spline control points. The proposed methods can provide a good preliminary design of the bar and can drive a material replacement process from a lightweight viewpoint.