## 3 Results  
### Results for the Screening of the Factors  
The finite element simulation for uniform loading was conducted for both low and high stiffness pallet segments. Table 4 shows the deflection results for the simulations of low and high stiffness boards when loaded with uniformly distributed forces of 109 kg and 218 kg, respectively, equivalent to 4.14 kPa and 8.27 kPa across the pallet segment's top deck. The complete unit load finite element (FE) model was solved for the 64 factor level combinations. Table 5 shows the individual \(p\)-values for each of the main factors and all of the second order interactions when using absolute pallet deflection as the main response. Effects and interactions were considered significant when they had a \(p\)-value lower than the selected \(p\)-value of 0.10 or when a higher order interaction included such effects. The \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Pallet Segment**} & \multirow{2}{*}{**Stiffness (GPa)**} & \multicolumn{2}{c}{**Deflection (mm)**} \\ \cline{3-4}  & & **108 kg** & **218 kg** \\ \hline Low stiffness & 2.76 & 22.7 & 44.9 \\ High stiffness & 8.27 & 7.51 & 14.7 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Simulation results for low and high stiffness pallet segments deflection (mm) under uniformly distributed loading. \begin{table}
\begin{tabular}{c c c} \hline \hline \multirow{2}{*}{**Factor**} & \multicolumn{2}{c}{**Factor Range**} \\ \cline{2-3}  & **Minimum** & **Maximum** \\ \hline Unit Load Columns & 3 & 6 \\ Pallet Friction & 0.20 & 0.70 \\ Box Friction & 0.20 & 0.70 \\ Payload Height (mm) & 508 & 2030 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Factor limiting ranges for each significant variable in the Gaussian Process Model. \(p\)-value limit of 0.10 was selected to decrease the probability of rejecting variables with lower levels of influence. These are considered to be the factors influencing the load bridging effect, which require further exploration. As expected, the stiffness of the board and the load applied are very significant factors influencing the resulting bending moment. Alternatively, when looking at the effect from the perspective of the change in deflection, which is the deflection ratio, weight and stiffness are non-significant factors. From a fundamental perspective, this is understandable since the ratio of deflection accounts for changes in stiffness and weight. It is important to note that these variables are not influencing the effects of other variables. No significant interaction for the deflection ratio analysis includes either payload weight or board stiffness. With this, it can be assumed that the rate of effect for the other factors, such as number of columns or payload height, are independent of the overall payload weight and pallet stiffness. Previous experimental studies have observed that, while maintaining the payload weight as a constant, load bridging is not relevant for high stiffness pallets. This suggests an interaction between pallet stiffness and load bridging [7; 12; 13; 14; 16]. Very high stiffness pallets present very low deflection results. Therefore, in order to be able to identify minute changes, extremely high consistency between experimental units and precise measurements are required. Such precision levels cannot always be achieved with current unit load testing methods. [PERSON] et al. [13] briefly explored the load bridging effects of modifying pallet stiffnesses but not the weight of the payload. It was noted that higher stiffness pallets