# Characterizing the Tensile Behaviour of Woven and Composite Fabrics under UV Exposure
## 4 Results and Discussions
### Tensile Properties Degradation  
The extent of photo-oxidation degradation was monitored through the tensile behaviour of geotextiles under various exposure levels. Table 2 summarizes the tensile test results of woven and composite-engineered fabrics in both machine direction (MD) and cross-machine direction (CD). The tensile test results were reported based on the arithmetic mean of three specimens. A comparison between engineered fabrics indicated that woven geotextiles had greater tensile strength and strain compared to composite geotextiles. The introduction of non-woven geotextiles as part of the composite geotextiles decreased the tensile properties of the individual woven geotextiles. The variability of tensile test results was studied based on the statistical analysis of the coefficient of variation (henceforth referred to as CV). Tensile test results in Table 2 show CV values ranging from 0.10% to 11.83% and 0.32% to 11.15% for woven and composite fabrics, respectively. Such a remarkably high CV value for geotextiles reveals a high degree of non-uniformity in the fabric structure. Geotextiles, after each month of weathering tests, were studied for their respective tensile strength and retained strain percentages. Figure 5 shows the plot of maximum tensile strength and its corresponding retained strain percentage against various exposure levels for both geotextiles in MD and CD. The tensile properties retained were calculated based on the tensile properties of the exposed specimens divided by the unexposed specimens and multiplied by 100%. Figure 5 shows that the woven geotextile progressively lost its maximum tensile strength under prolonged UV exposure. Such degradation was associated with retained strength percentages of 74.06% and 69.55% in the final month of UV exposure in the MD and CD, respectively. The retained strength percentage for woven geotextiles after each month of outdoor exposure was relatively consistent and \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{3}{*}{**Geotextiles**} & \multirow{3}{*}{**Months**} & \multicolumn{4}{c}{**Machine Direction**} & \multicolumn{4}{c}{**Cross-Machine Direction**} \\ \cline{3-10}  & & \(T_{max}\) [kN/m] & \(\epsilon_{max}\) [\%] & **CV (\(T_{max}\))** & **CV (\(\epsilon_{max}\))** & **CV (\(T_{max}\))** & **CV (\(\epsilon_{max}\))** \\  & & & & [\%] & **[\%]** & **[\%]** & **[\%]** & **[\%]** & **[\%]** \\ \hline \multirow{6}{*}{Woven} & 0 & 136.87 (\(\pm\)0.32) & 10.76 (\(\pm\)0.33) & 0.21 & 2.74 & 133.65 (\(\pm\)0.15) & 8.33 (\(\pm\)0.15) & 0.10 & 7.13 \\  & 1 & 127.67 (\(\pm\)1.46) & 10.85 (\(\pm\)0.79) & 1.01 & 6.39 & 123.11 (\(\pm\)4.21) & 8.29 (\(\pm\)4.21) & 3.02 & 8.87 \\  & 2 & 124.99 (\(\pm\)3.20) & 9.56 (\(\pm\)1.28) & 2.26 & 11.83 & 122.65 (\(\pm\)8.90) & 7.48 (\(\pm\)8.90) & 6.41 & 5.51 \\  & 3 & 119.03 (\(\pm\)11.47) & 9.84 (\(\pm\)0.09) & 8.52 & 0.79 & 114.72 (\(\pm\)2.33) & 6.89 (\(\pm\)2.33) & 1.80 & 4.50 \\  & 4 & 106.65 (\(\pm\)6.64) & 9.82 (\(\pm\)0.64) & 5.50 & 5.76 & 102.98 (\(\pm\)2.21) & 6.70 (\(\pm\)2.21) & 1.89 & 4.22 \\  & 5 & 101.36 (\(\pm\)1.03) & 9.80 (\(\pm\)0.16) & 0.89 & 1.46 & 92.95 (\(\pm\)2.86) & 6.72 (\(\pm\)2.86) & 2.72 & 10.98 \\ \hline \multirow{6}{*}{Composite} & 0 & 60.95 (\(\pm\)5.04) & 8.13 (\(\pm\)0.91) & 7.30 & 9.94 & 52.91 (\(\pm\)3.49) & 6.24 (\(\pm\)0.11) & 5.83 & 1.52 \\  & 1 & 61.76 (\(\pm\)0.22) & 8.37 (\(\pm\)0.12) & 0.32 & 1.27 & 52.84 (\(\pm\)0.49) & 5.92 (\(\pm\)0.30) & 0.82 & 4.54 \\ \cline{1-1}  & 2 & 65.75 (\(\pm\)3.99) & 8.26 (\(\pm\)0.60) & 5.37 & 6.41 & 59.91 (\(\pm\)1.77) & 6.40 (\(\pm\)0.06) & 2.61 & 0.87 \\ \cline{1-1}  & 3 & 65.72 (\(\pm\)3.32) & 8.89 (\(\pm\)0.95) & 4.47 & 9.44 & 64.11 (\(\pm\)0.89) & 6.79 (\(\pm\)0.13) & 1.22 & 1.71 \\ \cline{1-1}  & 4 & 54.00 (\(\pm\)0.80) & 9.24 (\(\pm\)1.17) & 1.32 & 11.15 & 63.38 (\(\pm\)5.77) & 6.38 (\(\pm\)0.36) & 8.04 & 4.96 \\ \cline{1-1}  & 5 & 57.41 (\(\pm\)0.98) & 8.19 (\(\pm\)0.90) & 1.51 & 9.76 & 60.16 (\(\pm\)1.40) & 5.15 (\(\pm\)0.30) & 2.06 & 5.12 \\ \hline \hline \end{tabular}
\end{table}