## 4 Parametric Study of SHSS Evaluation Methods
### Effect of Stress Type  
As described in the previous section, two types of governing stresses were produced at the RD joint to study four different SHSS evaluation methods. Essentially, bending in the deck-plate produced highly non-linear stress at the deck-toe, and the membrane effect in the rib-plate produced linear compressive stress at the rib-toe. Figure 9a,b shows SHSS results obtained for both the cases. The WTSs are also presented for comparison. The SSE methods were less influenced by stress type and had consistent SHSS results for both cases. The QSE method gave better results in the case of the deck-toe due to its quadratic nature, which incorporates the non-linear stress and gives a better representation of the actual stress scenario at the hot-spot. In the case of the deck-toe, the LSE methods gave somewhat lower SHSS results as compared to the QSE method, which was quite evident in the case of the LSE 515 method, whereas for the rib-toe, LSE methods showed slightly higher results in comparison to the QSE method, but the 2-CH8 element was exception. It is important to note that stresses were exceptionally converged for both cases when the LSE 515 method was used. The LSE 515 showed quite smooth results for the deck-toe, even for the 2-CH8 element, but SHSS results were low due to linear stress distribution. Moreover, its first readout point was at a distance of 0.5\(t\) from the weld-toe, which became 8.0 mm for the deck-toe. This further reduced the SHSS results where stresses were highly non-linear. This statement is further strengthened by rib-toe results, where the QSE method gave lower results as compared to the LSE 515 method, especially in solid parabolic elements (CH20/20E), because of the larger weld area nominal stresses being reduced near the weld-toe, which were picked by the QSE method. Therefore, the QSE method generally gave better results in the high stress concentration zone due to its quadratic nature, but if we are interested in the calculation of nominal stresses, then LSE 515 is a better choice in SSE methods. The [PERSON] and Xiao and Yamada methods are more sensitive to element type and mesh size variation as compared to other methods (Figure 9a,b). The scatter in their results is quite justified, as we relied on a single reference point for their SHSS results, i.e., at 2.5 mm and 1.0 mm, respectively. The Haibach method showed better results in the case of the deck-toe for solid parabolic elements (CH20/20E), while solid linear single elements (CH8E) and shell parabolic elements (1/2-CQ8) gave low SHSS results. In the case of the rib-toe, the results were quite smooth and almost identical to SSE methods. In fact, the stress at the same distance varied as we changed the element type or the mesh size, especially where stress was highly non-linear (i.e., the deck-toe). Therefore, it is better to use only CH20E elements while using the [PERSON] method. In the Xiao and Yamada method, the SHSS results were quite scattered in the case of the deck-toe, while for the rib-toe, the results were rather better (Figure 9a,b). These anomalies in SHSS results are not encouraging regarding the use of this method, especially with strict mesh size limitations. The ASME TTSL method performed better in the case of the deck-toe while the nodal averaging feature was turned on, and results were quite consistent for each element type and mesh size used in this study. It gave higher SHSS results for the CH20 elements as compared to other methods that represent the actual stress scenario at the deck-toe (Figure 9a). This method linearized the stress over the thickness of the plate at the weld-toe, therefore, it included part of the non-linear stress present at the weld-toe, while other SHSS evaluation methods do not include non-linear stress, as the readout points are away from the weld-toe. For the rib-toe, two distinguished lines converged to one point, unlike other methods (Figure 9b).