## 3 Results and Discussion
### Burger Model  
Experimental graphs were fitted by means of the Burger model. A computational software, OriginPro 7.5, was implemented to plot a non-linear curve fit to identify four parameters (\(E_{e}\), \(E_{d}\), \(\eta_{d}\), \(\eta_{k}\)) as shown in Table 4. The Burger model is usually executed in creep data evaluation due to its elaborate elastic and viscoelastic properties of anisotropic beam based on the working load within the creep period. In general, the elastic material demonstrated no residual deformation when the stress was detached from the structure. On the other hand, the viscoelastic property displayed a stress relaxation condition over time. The basis of the model was a combination of Burger's elements within the working load condition. However, the structure system would differently respond in terms of creep strain depending on the types of elements in the model [21]. Figure 11 depicts the values of \(E_{e}\) at different locations in wooden cross-arm for both current and additional bracing arms. The elasticity parameter or \(E_{e}\) was obtained from the data of instantaneous creep strain after execution of stress. From the results, it showed that the elastic performance of the cross-arm's beam decreased from the fixed point to free end. This happened due to stress along the cantilever beam which would decrease linearly from fixed to free end [34]. Apart from that, the finding displayed that braced cross-arm had higher \(E_{e}\) value compared to the existing cross-arm. This could be due to the retrofitting of \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Cross-Arm Configuration**} & \multicolumn{2}{c}{**Current**} & \multicolumn{2}{c}{**Braced**} \\ \cline{2-5}  & **Right** & **Left** & **Right** & **Left** \\ \hline Stress independent material exponent, \(n\) & 0.8016 & 0.5188 & 0.3686 & 0.2464 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Stress independent material exponent, \(n\) of both current and braced wooden cross-arms. braced arms which provided a sufficient restraining force to ease the residual deflection. Moreover, the increasing elastic modulus, \(E_{e}\), indicated the enhancement of the tensile modulus [48]. This would increase their stiffness to resist plastic deformation to maintain their working load during their long-term service period [49]. In this study, another parameter was being evaluated, \(\eta_{\text{k}}\), which represented the relaxation coefficient for the viscoelastic property. Moreover, the viscoelastic parameter, also known as irrecoverable creep strain, demonstrated the relaxation response over time [23]. Figure 12 displays the viscoelastic properties for both cross-arms (braced and existing cross-arms), showing relatively the same values of viscoelastic modulus. This illustrated that the bracing system did improve the viscoelastic properties of the cross-arm's structure in terms of relaxation time especially at y5 location. This showed that the bracing arms increased the relaxation of the cross-arm under long-term constant load. Apart from that, both cross-arms exhibited linear viscoelastic property along the beam length since the set working load was below the critical value of applied stress. If a critical stress was achieved during the creep cycle, the creep rate grew disproportionately faster [50].