## 3 Results and Discussion
### Geometric Evaluation
#### 3.3.2 Influence of \(P_{z}\) and \(h_{s}/t_{s}\) over \(\sigma_{uN}\)
For the highest value \(h_{s}/t_{s}\) = 6.77 (Figure 25a), the moment of inertia of the stiffeners was so high that it limited their \(U_{z}\) displacements, acting close to dividing the plate into smaller sections. Due to the low number of longitudinal stiffeners, the spacing \(S_{ls}\) between them was significant, allowing the plate to displace into areas less influenced by the stiffeners, such as the upper and lower corners. Hence, when lateral pressure and biaxial compressive loading were applied, high displacements occurred at the plate corners, leading to local displacements and collapse. The stress distribution in this case (Figure 26a) showed a poor distribution, with a high concentration of stress only in the plate, ultimately resulting in local collapse. When \(h_{s}/t_{s}\) was reduced to 3.83, the moment of inertia of stiffeners decreased, allowing the stiffeners to displace in \(U_{z}\) (Figure 25b). This behavior improved the distribution of displacements across the plate and the stiffeners, including at the upper and lower corners and at the center of the stiffened plate. In addition, \(\sigma_{uN}\) was not increased with the reduction of \(h_{s}/t_{s}\) from 6.77 to 3.83, but the geometric configuration resulted in a reduction in maximum local displacements of the plate that also led to local collapse. The stress distribution (Figure 26b) also improved with the reduction of \(h_{s}/t_{s}\), with a larger area now concentrating the stress more evenly across the plate. Further reduction of \(h_{s}/t_{s}\) (Figure 25c) significantly improved the \(U_{z}\) displacement, leading to better displacement distribution between the plate and stiffeners. While the plate  
Figure 16:3 Results of the application of lateral pressure and subsequent biaxial compressive loading on von Mises stress of P(2;4) with different values of \(h_{s}/t_{s}\): (**a**) \(h_{s}/t_{s}\) = 6.77, (**b**) \(h_{s}/t_{s}\) = 3.83, (**c**) \(h_{s}/t_{s}\) = 2.46, and (**d**) \(h_{s}/t_{s}\) = 0.78.  
still experienced local displacements at the upper and lower corners without failure, local displacements at the center ultimately led to local collapse. The more balanced displacement distribution enhanced the achievement of \(\left(\sigma_{uN}\right)_{m}\) and \(\left(h_{s}/t_{s}\right)_{o}\) for this configuration. Stress distribution (Figure 26c) also improved, with stress concentration previously limited to the plate now also distributed across the transverse stiffeners. This behavior resulted in the plate and stiffeners working together as a cohesive system, achieving the maximum value \(\left(\sigma_{uN}\right)_{m}\) for this case. Finally, reducing \(h_{s}/t_{s}\) to the lowest value of 0.78 (Figure 25d) significantly reduced the moment of inertia of the stiffeners, improving \(U_{z}\) in these components and causing them to exhibit the highest displacements. The stiffeners displaced more easily along with the plate, offering minimal resistance to out-of-plane displacements. This behavior resulted in the global displacement distribution of the system, occurring early during lateral pressure application, with displacement continuing as biaxial compression progressed, ultimately leading to global collapse. In contrast to previous configurations, when \(h_{s}/t_{s}\) was significantly reduced (Figure 26d), the geometry showed the worst stress distribution and \(\sigma_{uN}\). The transverse stiffeners exhibited a concentration of stress immediately after applying lateral pressure, causing global collapse before any significant stress was distributed across the plate.