## 5 Results and Discussion
### Nonlinear Models  
To develop a deeper understanding of the plastic behavior of the seat component, nonlinear models were analyzed. These models incorporated both geometric and material nonlinearities, with one assuming uniform properties and the other utilizing mapped thickness and mechanical properties derived from the stamping simulation. By considering localized yield stresses and the effects of work hardening, the nonlinear models provided a more accurate representation of the structural behavior under high loads, capturing stress redistributions and plastic deformations in critical regions. The results of the nonlinear simulations reveal that all the predicted values are lower than those observed in real experiments, indicating that the models exhibit greater rigidity compared to the actual sheet-metal. A detailed comparison of the two nonlinear models highlights key differences. At Points A and B, the uniform property model deforms more than the mapped model. This behavior is attributed to the assumption that the uniform model's material is equivalent to virgin sheet-metal, with yielding occurring above 153 MPa, which increases displacement. Conversely, at Point C, the uniform model predicts lower values, likely due to localized breakage in an area above the sampling point. This failure prevents further downward transmission, reducing the measured displacement. Despite higher relative errors, the mapped model provides results that align more closely with real-world observations. The relative errors in the mapped model's predictions are more consistent across sampling points, while those in the uniform property model vary significantly, with deviations spanning approximately thirty percentage units. However, the magnitudes of the measurements differ significantly across sampling points, ranging from 12 mm at larger displacements to just 0.5 mm at smaller ones. The similarity in displacement at Points A and B in the uniform property model appears coincidental, stemming from the elasto-plastic hardening material behavior assumed in this model. In this approach, once the yield strength is exceeded, the tension continues to increase, enhancing the resistance. In contrast, the mapped model incorporates elasto-plastic material behavior, reacting with  
Figure 14: Stresses of the sheet-metal seat from the (**a**) uniform and (**b**) mapped thickness models. Figure 13: Strain of the sheet-metal seat from the (**a**) uniform and (**b**) mapped thickness models. a constant resistant load once the yield value is reached. This distinction results in differing deformation trends between the two models. Residual data analysis indicates that both simulations underestimate the real-world behavior, showing weaker and more deformable characteristics. The material models used in the simulations allow for earlier failure compared to that observed in reality. Notably, the uniform property model poorly represents the experimental results, as evidenced by significant virtual deformation and compromised elastic return, indicating inappropriate material model and reference data choices. In contrast, the mapped model demonstrates better agreement with real behavior at Points A and B, though it deviates more significantly at Point C. The discrepancies at Point C may arise from experimental errors or limitations in the simulation data, particularly when dealing with displacement on the order of hundredths of a millimeter, which are negligible relative to the overall body size. Figures 15 and 16 compare the plastic strain and deformation contours for both simulations. The iso-strain areas in the mapped property model are significantly smaller than those in the uniform model, reflecting localized yielding near the base and L-Plate edges, which are expected regions for constraint reaction interfaces. The legend scale was standardized across both models for the direct comparison of plastic deformations and strains, further highlighting the differences in behavior between the models.