## 4 Discussion  
By comparing the results from both elastic and inelastic assessments, it can be seen that the elastic criteria provide a too conservative estimate of the design safety. Compared \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Part**} & \multirow{2}{*}{**Loc.**} & \multirow{2}{*}{\begin{tabular}{c} \(\mathbf{T_{average}}\) \\ (\({}^{\circ}\)C) \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} \(\mathbf{(\tilde{\epsilon}_{m})_{pl}}\) \\ (\%) \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} \(\mathbf{\frac{\epsilon_{g}}{\%}}\) \\ (\%) \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} \(\mathbf{IPFL}\) \\ **Criteria** \\ **Margin** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} \(\mathbf{T_{point}}\) \\ (\({}^{\circ}\)C) \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} \(\mathbf{(\tilde{\epsilon})_{pt}\times TF}\) \\ (\%) \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} \(\mathbf{\varepsilon_{tr}}\) \\ **(\%)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} \(\mathbf{\frac{\epsilon_{tr}}{\%}}\) \\ **Margin** \\ \end{tabular} } \\ \cline{3-10}  & & A & 511 & 0.0000\% & 0.4374\% & 100\% & 514 & 0.00\% & 14.60\% & 100\% \\ \cline{2-10}  & B & 523 & 0.0000\% & 0.3702\% & 100\% & 524 & 0.00\% & 14.92\% & 100\% \\ \cline{2-10}  & C & 516 & 0.0000\% & 0.4108\% & 100\% & 516 & 0.00\% & 14.66\% & 100\% \\ \hline \multirow{2}{*}{\begin{tabular}{c} \(\mathbf{\frac{\epsilon_{tr}}{\%}}\) \\ (\%) \\ \end{tabular} } & A & 516 & 0.0000\% & 0.4084\% & 100\% & 516 & 0.00\% & 14.66\% & 100\% \\ \cline{2-10}  & B & 514 & 0.0000\% & 0.4197\% & 100\% & 514 & 0.00\% & 14.60\% & 100\% \\ \hline \multirow{2}{*}{\
\begin{tabular}{c} \(\mathbf{\frac{\epsilon_{tr}}{\%}}\) \\ (\%) \\ \end{tabular} } & A & 414 & 0.0060\% & 0.2706\% & 98\% & 414 & 0.04\% & 11.43\% & 100\% \\ \cline{2-10}  & B & 441 & 0.0014\% & 0.3436\% & 100\% & 446 & 0.01\% & 12.36\% & 100\% \\ \cline{2-10}  & C & 442 & 0.0000\% & 0.3456\% & 100\% & 446 & 0.00\% & 12.36\% & 100\% \\ \cline{2-10}  & D & 409 & 0.0012\% & 0.2581\% & 100\% & 410 & 0.01\% & 11.33\% & 100\% \\ \hline \multirow{2}{*}{
\begin{tabular}{c} \(\mathbf{\frac{\epsilon_{tr}}{\%}}\) \\ (\%) \\ \end{tabular} } & A & 500 & 0.3824\% & 0.4993\% & 23\% & 499 & 0.42\% & 14.10\% & 97\% \\ \cline{2-10}  & B & 517 & 0.1057\% & 0.4028\% & 74\% & 517 & 0.13\% & 14.69\% & 99\% \\ \cline{2-10}  & C & 517 & 0.2214\% & 0.4020\% & 45\% & 517 & 0.28\% & 14.69\% & 98\% \\ \cline{2-10}  & D & 516 & 0.0655\% & 0.4108\% & 84\% & 515 & 0.08\% & 14.63\% & 99\% \\ \cline{2-10}  & E & 518 & 0.0913\% & 0.3978\% & 77\% & 518 & 0.10\% & 14.73\% & 99\% \\ \cline{2-10}  & F & 516 & 0.1854\% & 0.4094\% & 55\% & 516 & 0.19\% & 14.66\% & 99\% \\ \cline{2-10}  & G & 518 & 0.0000\% & 0.3973\% & 100\% & 518 & 0.00\% & 14.73\% & 100\% \\ \cline{2-10}  & H & 509 & 0.2996\% & 0.4487\% & 33\% & 508 & 0.32\% & 14.40\% & 98\% \\ \cline{2-10}  & I & 506 & 0.4854\% & 0.4626\% & Failed & 506 & 0.50\% & 14.33\% & 97\% \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._  
Figure 11: Stress triaxiality contour on BB cap region—inelastic analysis. to normal ductile materials, Eurofer97 has a limited strain-hardening capability, but the material retains considerable ductility after necking. The elastic design-by-analysis code does not take this factor into account. Consequently, the stress limits derived from the ultimate tensile strength values for the elastic assessment are affected by the lack of strain hardening capability of Eurofer97. Particularly for the IPFL damage mode, the stress limits are much below the yield point as shown in Figure 4. Corresponding inelastic assessment is based on the plastic strain limits and hence it is not affected by this problem. This is reflected in the improved assessment results for IPFL damage mode using the inelastic criteria.