## 2 Modelling and Methods
### Masonry Wall Assembly Finite Element (FE) Models
#### 2.1.2 Model Material Properties and Combinations  
The range of material properties incorporated into the FE models enriched the available analysis cases and consequently provided a wide variety of output data. The properties and their values considered as part of the FE analysis included:  
* Clay brick density (\(\rho\)): 2000 kg/m\({}^{3}\) and 1000 kg/m\({}^{3}\). * Clay brick thermal conductivity coefficient (\(\lambda\)): 0.8 W/(m\(\cdot\)K) and 0.4 W/(m\(\cdot\)K). * Clay brick thermal emissivity coefficient (\(\epsilon\)): 0.1, 0.5, 0.9. * Insulation thickness (d): 0 mm, 50 mm, 100 mm. The above range of variables and material property values allowed for the formation of the following combinations. Each combination appearing in Table 1 represents a separate FE model whose analysis output subsequently offered portions of the overall input data for training, testing, and evaluating the ANN model. The development of a complete finite element analysis model required the definition of some additional parameters (which were not explicitly used for the development of the ANN). The specific heat capacity (C\({}_{\text{p}}\)) of all components needed to be specified, along with the density (\(\rho\)) and thermal conductivity coefficient (\(\lambda\)) of the cement mortar and insulation panels. Table 2 summarises this additional information. Figure 3: Sections of typical masonry wall assemblies modelled as part of this study. (**a**) Wall section insulated externally, (**b**) non-insulated wall section, (**c**) wall section insulated internally. It is worth highlighting that although most of the thermophysical and mechanical properties of the masonry structure fluctuate depending on the temperature of the components [23], for the needs of this study they have all been assumed to remain constant throughout the development of the phenomenon. It has also been shown that clay brick spalling affects the thermal performance of the masonry wall when exposed to fire [24; 25]; this parameter has not been considered in the finite element models. The dramatic impact on the insulation's performance, due to phase change when exposed to high temperatures, could not be ignored. The modelling convention used to reflect this characteristic behaviour is explained in the following paragraphs. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Insolution Position and** & **Brick Density** & **Thermal Conductivity Coefficient** & **Thermal Emissivity Coefficient** & **Sample Reference 1** \\ \hline No insulation & 1000 & 0.4 & 0.1 & Smpll-1 \\
1000 & 0.4 & 0.5 & Smpll-2 \\
1000 & 0.4 & 0.9 & Smpll-3 \\ \hline No insulation & 2000 & 0.8 & 0.1 & Smpl2-1 \\
2000 & 0.8 & 0.5 & Smpl2-2 \\
2000 & 0.8 & 0.9 & Smpl2-3 \\ \hline Non-exposed EPS (50 mm) & 1000 & 0.4 & 0.1 & Smpl3-1 \\
1000 & 0.4 & 0.5 & Smpl3-2 \\
1000 & 0.4 & 0.9 & Smpl3-3 \\ \hline Non-exposed EPS (50 mm) & 2000 & 0.8 & 0.1 & Smpl4-1 \\
2000 & 0.8 & 0.5 & Smpl4-2 \\
2000 & 0.8 & 0.9 & Smpl4-3 \\ \hline EPS exposed to fire (50 mm) & 1000 & 0.4 & 0.1 & Smpl5-1 \\
1000 & 0.4 & 0.5 & Smpl5-2 \\
1000 & 0.4 & 0.9 & Smpl5-3 \\ \hline EPS exposed to fire (50 mm) & 2000 & 0.8 & 0.1 & Smpl6-1 \\
2000 & 0.8 & 0.5 & Smpl6-2 \\
2000 & 0.8 & 0.9 & Smpl6-3 \\ \hline Non-exposed EPS (100 mm) & 1000 & 0.4 & 0.1 & Smpl7-1 \\
1000 & 0.4 & 0.5 & Smpl7-2 \\
1000 & 0.4 & 0.9 & Smpl7-3 \\ \hline Non-exposed EPS (100 mm) & 2000 & 0.8 & 0.1 & Smpl8-1 \\
2000 & 0.8 & 0.5 & Smpl8-2 \\
2000 & 0.8 & 0.9 & Smpl8-3 \\ \hline EPS exposed to fire (100 mm) & 1000 & 0.4 & 0.1 & Smpl9-1 \\
1000 & 0.4 & 0.5 & Smpl9-2 \\
1000 & 0.4 & 0.9 & Smpl9-3 \\ \hline \multirow{2}{*}{EPS exposed to fire (100 mm)} & 2000 & 0.8 & 0.1 & Smpl10-1 \\  & 2000 & 0.8 & 0.5 & Smpl10-2 \\ \cline{1-1}  & 2000 & 0.8 & 0.9 & Smpl10-3 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Material property combinations defining the various FE models analysed.