## 3 Results and Discussion
### Stress Transfer Behaviors  
First, we wanted to investigate the relationship between the porosity of the knitted BSCs and the von Mises stresses of the human body during the BSC decreasing the model's abdomen circumference. Set the boundary conditions as the abdomen circumference decreasing 10 cm, and the following results as shown in Table 3. While the BSC-1 was used as the FEA model, the von Mises stresses were varied from 0.0076 MPa to 337.79 MPa (Figure 4), and most of stresses were concentrated in the croth portion and the central abdomen portion. In the croth portion, the BSC has less contact area with the human body. During the abdomen decreasing period, the clothing might cause more stress and pressure on the human body. Therefore, choosing the BSC in the croth portion should be considered first, and we might choose a more soft and flexible BSC in the croth portion of the clothing, or change the clothing design, such as the lock using, to prevent the stress concentration. Figure 3: The linear regression model is the relationship between the porosity and the elastic modulus of the knitted BSCs. After series FEA, the following results were calculated by SPSS. The von Mises stress of the human body was \(7.22\pm 0.40\) kPa. The relation between the porosity of the BSCs and the von Mises stress of the human body was calculated by the correlation analysis, Pearson correlation coefficient was \(-0.996\) (\(p<0.01\)). In other words, the porosity and the stresses on the human body emerge a strong negative relationship. The linear correlation coefficient is R\({}^{2}\) = 0.991 (\(p<0.01\)), and the linear regression Equation (2) can be gained. \[\sigma_{body}=\sigma_{body}{}^{\prime}(1-0.43P) \tag{2}\]  
Figure 4: Von Mises stress distribution of the FEA results with BSC-1 sample during the abdomen decreasing period: (**a**) frontal view of the BSC, (**b**) back view of the BSC, (**c**) frontal view of the human body, and (**d**) back view of the human body. \begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Porosity (\%)** & **Elastic Modulus** & **Stress of the** & **Stress of the Human** & **Abdomen Circumference** \\  & **(GPa)** & **BSC (MPa)** & **Body (kPa)** & **Decreasing (cm)** \\ \hline BSC-7 (38.46) & 1.58 & 207.30 & 6.742 & 10 \\ BSC-6 (35.18) & 1.91 & 249.98 & 6.783 & 10 \\ BSC-5 (29.98) & 2.00 & 267.13 & 6.910 & 10 \\ BSC-4 (18.91) & 2.12 & 282.20 & 7.365 & 10 \\ BSC-3 (14.00) & 2.15 & 287.28 & 7.523 & 10 \\ BSC-2 (12.73) & 2.23 & 289.04 & 7.588 & 10 \\ BSC-1 (10.28) & 2.57 & 337.79 & 7.645 & 10 \\ BSC-1 (10.28) & 2.57 & 506.53 & 11.464 & 15 \\ BSC-1 (10.28) & 2.57 & 675.60 & 15.283 & 20 \\ BSC-1 (10.28) & 2.57 & 845.12 & 19.109 & 25 \\ BSC-1 (10.28) & 2.57 & 1032.48 & 22.825 & 30 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Experiment results between the porosity, the elastic modulus of the knitted BSCs, the abdomen circumference decreasing, and the stress of the BSC and human body. where \(P\) is porosity, \(\sigma_{body}\) is the estimated stresses average of the human body, and \(\sigma_{body}\)' is the stresses of the human body. Then, increased the displacement of the abdomen circumference decreasing until the designed abdomen circumference 27 inch with BSC-1 sample. When the abdomen had decreased 12 inches (about 3-times the 10 cm displacement) (Figure 5), the von Mises stresses varied from 0.0228 MPa to 1032.5 MPa. As result, the following von Mises stresses of the BSC and the human body were growth in multiples with the displacement increased multiples. Therefore, we also used SPSS to conclude the Equation (3) which means the relationship between the porosity of the knitted BSCs (\(P\)), the displacement of the abdomen circumference decreasing (\(\Delta L\)), the original length of the abdomen (\(L_{0}\)), the von Mises stresses of the human body (\(\sigma_{body}\)') and the estimated von Mises stresses of the human body (\(\sigma_{body}\)).