## 4 Discussion  
The results obtained in PA6 (Figure 4a) are very similar when applying the ASED and the EMC-ASED criteria, given that the material tensile curve is almost linear elastic and \(\sigma_{\mathrm{f}}\)* is slightly higher than \(\sigma_{\mathrm{u}}\). In any case, it corresponds to a situation where these energetic criteria do not provide fully satisfactory results, with an accuracy level around 75%. The predictions are, in any case, conservative. Concerning the SGFR PA6 (Figure 4b,c), the predictions provided by the EMC-ASED criterion are moderately different to those provided by the ASED criterion. This is caused by the (moderate) nonlinearity of the corresponding tensile curves. In the case of SGFR PA6 5 wt.%, the EMC-ASED criterion improves the predictions provided by the ASED criterion, increasing the average accuracy from 86.3% to 96.7%, whereas in the case of SGFR PA6 50 wt.%, the accuracy goes from 92.0% up to 113.5%. The latter case provides acceptable predictions in both cases (considering the inherent scatter obtained experimentally), but the ASED criterion provides more accurate conservative results. The reason  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Material**} & **Notch Radius, \(\rho\)** & **P\({}_{\text{exp}}\)** & **P\({}_{\text{ASED}}\)** & **P\({}_{\text{EMC-ASED}}\)** & **P\({}_{\text{ASED}}\)/P\({}_{\text{exp}}\)** & **P\({}_{\text{EMC-ASED}}\)/P\({}_{\text{exp}}\)** \\  & **(mm)** & **(kN)** & **(kN)** & **(kN)** & **(kN)** & \\ \hline \multirow{4}{*}{PA6} & 0.25 & 0.1049 & 0.0683 & 0.0748 & 0.724  
for this situation is the results obtained for larger radii, whose corresponding load-displacement curves present nonlinear behaviour [7] in SGFR PA6 50 wt.%, and fully linear in SGFR PA6 5 wt.%. Such nonlinearity generates a loss of accuracy, given that the EMC corrects the nonlinear behaviour of the tensile stress-strain curve, but it does not correct the nonlinear behaviour (if any) of the fracture behaviour. The analysis of PMMA is shown in Figure 5. A clear improvement can be observed in the accuracy of the predictions, which increases from 77.0% (ASED criterion) up to 103.4% (EMC-ASED criterion). This is a clear case of applicability of the EMC-ASED criterion, given that it is a material presenting a nonlinear tensile curve (whose nonlinearity may be corrected by the EMC), and linear-elastic load-displacement curves in the fracture tests (although a slight nonlinear behaviour may be observed in the curves for \(\rho\) = 2.0 mm and \(\rho\) = 2.5 mm) [17]. Figure 6 presents the results obtained in AI7075-T651. This material presents a clear nonlinear behaviour in the tensile test (with the strain under maximum load, \(\epsilon_{\text{max}}\), being 9.90%), linear-elastic load-displacement curves in the fracture tests for notch radii up to 0.47 mm, and a certain nonlinear behaviour for larger radii (1.0 and 2.0 mm) [18]. The evident nonlinear tensile curve generates very poor predictions of the ASED criterion, with the average value being 31.9%. However, the application of the EMC-ASED criterion provides accurate conservative results (86.0% of accuracy). Finally, Figure 7 shows the results obtained in steel S275 JR. A similar tendency can be observed in the three temperatures being analysed, with very poor predictions of the ASED criterion (caused by the nonlinear tensile curve in the three situations [22]), and clear overestimations of the fracture loads when applying the EMC-ASED criterion. This is something reasonable for working temperatures of \(-\)50 and \(-\)10 \({}^{\circ}\)C, both belonging to the DBTZ and, thus, developing elastoplastic behaviour even in cracked conditions (which is not corrected when applying the EMC). However, in principle, the EMC-ASED criterion should provide good results in this material at \(-\)120 \({}^{\circ}\)C, given that the corresponding tensile curve is nonlinear, but its working temperature (and fracture behaviour) corresponds to the material Lower Shelf, with brittle, almost fully linear-elastic behaviour.