## 5 Discussion
### Method of Corrected Similarity  
Generally, three criteria were utilized to ensure that the significant geometric parameters of the stiffener remained consistent, which enabled a partial similarity in the dominant behavior and compensated for the distorted stiffener configuration in different situations. **Criterion 1**: Maintain the sectional static moment and sectional area of the integrated stiffener consistent with the reference model; correct the impact mass using Equation (24) if necessary;  
**Criterion 2**: Maintain the sectional area and web thickness of the integrated stiffener consistent with the reference model; correct the impact mass using Equation (24) if necessary;  
Figure 30: Comparison of empirical equation and numerical results of most appropriate distorted models. **Criterion 3**: Maintain the web thickness of the integrated stiffener consistent with the reference model and the ratio \(P_{1}/P_{cr\text{-}e}\) to satisfy the empirical equation, Equation (28), and maintain an impact mass consistent with the reference model. By addressing the complex distortion problem as two separate distortions, the correction procedure illustrated in flowchart Figure 31 facilitates comprehension and provides a visual representation. The objective of the similarity procedure is to design a small-scale model exhibiting a reasonably distorted sectional configuration that differs from that of the prototype (Figure 31 [1]). This design is intended to be practical and attainable in experimental settings, making it convenient for conducting experiments. First of all, the target distorted small-scaled model provides a specific overall scaling factor \(\beta\), which is determined as the ratio of the plate length of the prototype structure to the plate length of the target model. To ensure a perfect similarity between the target distorted small-scaled model and the prototype, the reference model is created with the same overall scaling factor \(\beta\) as the target distorted small-scaled model. This allows for a direct comparison and replication of their structural behavior and responses (Figure 31 [2]). The dimensions and load case of the reference model were identical, to be perfectly similar to those of the prototype. The related scaling factor between the reference model and prototype can be calculated using classic similarity laws, as presented in Table 4.  
If the target distorted small-scaled model exhibits plate thickness distortion, the first step is to establish a distorted model I to account for the distorted thickness and calculate the corresponding scaling factor \(\lambda\) through Equation (17) (Figure 31 [4]). Once the designed distorted model I was established by incorporating the distorted plate thickness and  
Figure 31: Correction procedure for distorted models to replica prototype. stiffener dimensions consistent with the reference model, the next step was to determine the corrected load case for this model. This can be achieved using Equation (19), while ensuring that the impact velocity remains the same as that of the reference model. Subsequently, simulations or experiments are conducted on distorted model I to obtain its dynamic responses (Figure 31 [6]), which can be reversed to reflect the behavior of the prototype using Equation (17), Tables 4 and 5 (Figure 31 [8]). On the basis of distorted model I, if the target distorted small-scaled model features a different stiffener configuration, distorted model II should be established (Figure 31 [5]). This model maintains the same attached plate thickness as distorted model I but incorporates distorted flat-bar stiffeners whose dimensions are determined, meeting the selected criteria. By utilizing the empirical equations in Equations (25) and (27) to calculate the static concentrated force \(P_{1}\) and critical buckling force \(P_{cr-e}\), a direct method for estimating the dominant behavior in the reference model was established based on the threshold ratio of \(P_{1}/P_{cr-e}\) from 1.55 to 3.21.