## 3 Finite Element Model
### Boundary Conditions  
To analyze the structural response under loading, an initial load input must be supplied to the F.E. model. Accurate loading conditions are critical, as the subsequent optimization analysis heavily depends on this input. Therefore, the analysis software was provided with the most detailed representation of boundary conditions possible, as displayed in Figure 7. This necessitated calculating the forces transmitted from the suspension system to the chassis during a specific cornering scenario. Although this process was complex due to the need to account for various suspension variables, the challenge was mitigated by implementing several simplifying assumptions, which are detailed below. * The parts of the suspension system are assumed to be of infinite rigidity, causing no changes in its geometry. * The forces are assumed to pass through the tire and rim assembly without deforming their geometries. * Loads are assumed to transfer directly to the chassis through the mounting brackets of the suspension arms, as depicted in Figure 8.  
Regarding the rationale for simplifying the finite element (F.E.) model by including only the composite section of the chassis, it is important to emphasize that these measures are primarily aimed at improving computational efficiency. Model simplification substantially decreases computational time and resource demands, which is particularly advantageous for large-scale analyses such as this. Furthermore, the reduction in computa  
Figure 8: A-arm forces on the chassis (red arrows—display of finite element graphics). Figure 7: Fixations of the chassis (cyan arrows—display of finite element graphics). tional cost facilitates the design optimization process by enabling the rapid evaluation of various composite material configurations, thereby expanding the scope for identifying the optimal design alternatives. Despite the benefits of simplifying the finite element model, inherent limitations arise, the principal one being the loss of accuracy caused by adopting fixed supports at the rear of the monocoque, as depicted in Figure 7, which simplistically represents the connection to the space-frame segment of the hybrid chassis due to neglecting its compliance. This simplification may lead to an overestimation of stress magnitudes within the composite structure. Nonetheless, since the mechanical properties of both components will be independently assessed through physical testing in the post-manufacturing phase, focusing the analysis exclusively on the composite section was considered an appropriate choice. The loading scenario assumes that the vehicle drives in a constant-radius turn, simulating a skid pad track of two interconnected circles, each with a 15.25 m radius, forming a figure-eight layout (Figure 9). The track width is specified as 3 m. For force calculations on the monocoque, the race car is modeled to traverse the midpoint of the right half of the track at a constant speed, completing a lap in 5.67 s. Consequently, the requisite inertial and reaction forces to achieve this lap time were determined. Subsequent to evaluating the suspension system's geometric characteristics, the resultant force components transmitted to the chassis were computed and applied as boundary conditions directly on the nodes corresponding to the interface surfaces (1-6) from Figure 10, between the suspension mounting brackets and the chassis. It is important to note that, due to the implemented assumptions, the results are anticipated to deviate from empirical test data. As a precautionary measure to accommodate anticipated abrupt increases in forces during racing conditions, the applied forces were scaled by a factor of 2.5. A static force analysis was executed due to the indeterminate variables inherent in dynamic analysis, as adopting a dynamic approach would complicate the model, compromise result accuracy, and increase the algorithm's execution time.