# Trawl Grid Structure Design and Analysis Using the Finite Element Method
## 4 Results and Discussion  
### The Taguchi Method  
The researchers used the Taguchi approach to optimize the design variables of the mesh structure while using finite element method models in the dynamic explicit environment of the Abaqus software. The mechanical work capacity of the grid cells was measured when stretched by the solid at a speed of 2 m/s. The stronger the displacement capacity of the grid cells, the better their load-carrying ability due to the non-linear features and excellent plastic deformation. With the movement of the impediment, the remaining portions are distorted and displaced. Table 3 displays the response table for the S/N ratio based on the larger-the-better quality attributes, demonstrating that: the test specimen made of PA with a cross-section of 0.4 mm and a length of 30 mm rendered the best mechanical work value when the blockage first contacted the mesh. However, the test piece made of PE, with a cross-section of 0.3 mm and a length of 20 mm, yielded the lowest result. These findings demonstrate that the capacity to produce mechanical work is significantly affected by the contact stiffness matrix.  
The process control variables impacting S/N ratios are presented in Figure 7. PA has the highest rating of \(-16.7\) when material variables are taken into account. Following that  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Ex.** & **Material** & **Cross-Section** & **Size of Grid Cell** & \(\delta\Omega_{t}^{Q}\) & \(D_{t}\) & \(W_{t}^{2}\) \\ \hline
1 & PA & 0.2 & 20 & 10.04 & 0.0102 & 0.102 \\ \hline
2 & PA & 0.3 & 25 & 14.47 & 0.0102 & 0.147 \\ \hline
3 & PA & 0.4 & 30 & 20.44 & 0  
is the PP material, with a value of \(-25.78\), and a small decrease in the value to \(-39.25\) for the PE material. The cross-section factor graph exhibits a strong increasing trend, demonstrating that the influence on signal-to-noise increases with cross-section size. The chart typically peaks at level 2 at \(-26.77\), drops to level 1 at \(-27.09\), and reaches level 3 at \(-27.89\) when the last component (the edge length of the grid cell) is considered. These findings demonstrate that the ideal net length is \(25\) mm. The rank of the design variables is shown in Table 4, with the best being the material variable; next is the cross-section and the size variable.  
As shown in Table 5, the value of \(\rho\) was used to determine the significance and relative importance of each factor through the estimated regression coefficient table. For the S/N ratio, the elements of material, cross-section, and size have \(\rho\) values of less than 0.05, at 0.003, 0.036, and 0.491, respectively (statistically significant at 0.05). These results indicate that the material has the greatest impact on the mesh structure, with a mean square of 385.9, accounting for 93% of the variance. The next most impactful element assessed was the cross-section, with a mean square of 26.2, contributing to 6% of the total, and the final element was the size, contributing 1%.  
\begin{table}
\begin{tabular}{c c c c} \hline
**Level** & **Material** & **Cross-Section** & **Size** \\ \hline
1 & \(-16.71\) & \(-29.95\) & \(-27.09\) \\ \hline
2 & \(-39.25\) & \(-27.69\) & \(-26.77\) \\ \hline
3 & \(-25.79\) & \(-24.1\) & \(-27.89\) \\ \hline Delta & 22.54 & 5.86 & 1.12 \\ \hline Rank & 1 & 2 & 3 \\ \hline \end{tabular}
\end{table}
Table 4: Response table for signal-to-noise (S/N) ratios with larger-the-better.  
Figure 7: Effects of process control on the signal—to—noise (S/N) ratios.  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline
**Design Variables** & **L1** & **L2** & **L3** & **SS** & **DF** & **MS** & \(\rho\) & \% \\ \hline A & Material & \(-16.71\) & \(-39.25\) & \(-25.79\) & \(771.8\) & 2 & \(385.9\) & \(0.003\) & \(93\) \\ \hline B & Section & \(-29.95\) & \(-27.69\) & \(-24.1\) & \(52.4\) & \(2\) & \(26.2\) & \(0.036\) & \(6\)