## 3 Results  
### Tensile Test Results  
Figure 2 shows the stress-strain curves obtained from the tensile tests, and Table 2 shows the average tensile test results for each sample as well as percentages of increase/decrease in the stitched samples over the unstitched material. Figure 2a corresponds to the stress-strain diagrams of composite N samples, where there is an average UTS of 187.6337 MPa and a strain of 0.0403 mm/mm. Figure 2b corresponds to the stress-strain diagrams of the 0.5 samples, where an average UTS of 193.5973 MPa and a strain of 0.0235 mm/mm were obtained, in addition to an increase in the slope of the lo curve, which results in a 99.20% higher average [PERSON]'s modulus compared to the N sample. Figure 2c corresponds to the 1.0 samples, where an average UTS of 189.7865 MPa was obtained, an average deformation of 0.0272 mm/mm, and a slight decrease in the slope, which indicates that [PERSON]'s modulus decreases in comparison with the 0.5 sample. Figure 2d corresponds to the stress-strain diagrams of the 1.5 samples, where an average UTS of approximately 188.9748 was obtained, an average strain of 0.0307 mm/mm, and a slight decrease in the slope concerning the previous sample, which indicates that [PERSON]'s modulus decreases. Finally, Figure 2e corresponds to the stress-strain diagrams of the 2.0 samples, where an average UTS of 188.6894 MPa and an average strain of 0.0334 mm/mm were obtained, resulting in a decrease in the slope of twice the curve, indicating a decrease in [PERSON]'s modulus from the previous curves. We can deduce that as the length between the stitching increases, [PERSON]'s modulus decreases the same way as the UTS. Studies have mentioned that the more stitching separation there is, the less tensile resistance there is, yet these studies used a rigid thread [23; 25], so flexibility in the thread is another major parameter to be considered. In the case of deformation, as the length separation of the stitching increases, the deformation increases slightly; this behavior can be attributed to the fact that the stitching threads carry most of the energy and reduce the stress within the matrix, and more energy is required to propagate the crack through the matrix, increasing tensile resistance, while at the same time the stitching reduces the propagation of delamination, which is a common mechanism on composite that also reduces tensile resistance [29; 30; 31; 32; 33; 34; 35; 36; 37]. Figure 3 shows the average mechanical properties comparison of the different samples obtained from the stress-strain diagrams. Table 3 shows the standard deviation of all the mechanical properties, in which all values are 5% less than the average, meaning the values tend to be close to the mean, and thus it is statistically reliable. Figure 3a shows the comparison of the average UTS of all samples. An increase of 3.17% was obtained in the 0.5 samples over the unstitched samples, but a decrease is shown between 1.0, 1.5, and 2.0 samples. Even so, there is a 0.56% increase in the 2.0 sample over N sample, which is the sample with most minor UTS of them all. This variation within the stitched \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Sample** & **UTS (MPa)** & **Strain (mm/mm)** & **E (GPa)** & **T (MJ/m3)** \\ \hline N & 187.6337 & 0.0403 & 5.1137 & 3.7400 \\
0.5 & 193.5973 (+3.17\%) & 0.0235 (\(-41.66\%\)) & 10.1870 (+99.20\%) & 2.3599 (\(-36.89\%\)) \\
1.0 & 189.7865 (+1.14\%) & 0.0272 (\(-32.47\%\)) & 8.6891 (+69.91\%) & 2.7196 (\(-27.28\%\)) \\
1.5 & 188.9748 (+0.71\%) & 0.0307 (\(-23.85\%\)) & 7.7145 (+50.85\%) & 3.192486 (\(-14.64\%\)) \\
2.0 & 188.6894 (+0.56\%) & 0.0334 (\(-16.99\%\)) & 6.7200 (+31.41\%) & 3.407956 (\(-8.87\%\)) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Mechanical properties obtained from tensile test. samples is attributed to the loose region between the stitching points, which affected resin permeability, resulting in the creation of voids and porosity [38].