# An Investigation on Base Metal Block Shear Strength of Ferritic Stainless Steel Welded Connection
## 4 Strength Comparison with Design Prediction and Recommendation
### Stress Analysis for Extended Variables  
The block shear strength equations in Table 4 are the values presented as a result of research on carbon steel bolted and welded connections, in which the first term on the right is the tensile fracture strength and the second term is the shear fracture strength or shear yield strength. The stress factor for tensile fracture strength is defined as 1.0 in Equations (1)-(3), and 1.25 in Equations (4) and (5), and the stress factor for shear fracture or shear yield strength is 0.6 or 1/\(\sqrt{3}\). In order to examine the tensile and shear stress factors at the ferritic stainless steel base metal fracture welded connections, the following stress factors were calculated from the finite element analysis results by investigating the  
\begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline  & & \multicolumn{6}{c}{**StrengthRatio(\(P_{ut}/P_{ut}\))**} \\ \cline{3-10}  & **Analysis** & \multicolumn{3}{c}{**KBC2016**} & & & & & & & & \\ \multirow{2}{*}{**Specimen**} & **Ultimate** & **(A1 SC2016)** & \multirow{2}{*}{**EC3 Equation (3)**} & \multirow{2}{*}{**[PERSON]**} & \multirow{2}{*}{**Diveriver**} & \multirow{2}{*}{**[PERSON] et al.**} \\  & **Strength** & **Equations (1)** & & & & & & & & \\  & **P\({}_{\text{an}}\)(kN)** & & & & & & & & & \\  & & & & & & & & & & \\  & & & & & & & & & & \\  & & & & & & & & & & \\ \hline FT20L20 & 87.09 & 48.00 & 0.55 & 42.66 & 0.49 & 82.19 & 0.94 & 60.02 & 0.69 & 83.57 & 0.96 \\ FT20L30 & 101.65 & 57.30 & 0.56 & 51.60 & 0.51 & 96.49 & 0.95 & 71.64 & 0.70 & 96.93 & 0.95 \\ FT20L40 & 114.87 & 66.59 & 0.58 & 60.54 & 0.53 & 110.79 & 0.96 & 83.26 & 0.72 & 110.30 & 0.96 \\ FT20L50 & 126.84 & 75.89 & 0.60 & 69.48 & 0.55 & 125.09 & 0.99 & 94.88 & 0.75 & 123.66 & 0.97 \\ FT20L60 & 137.67 & 85.18 & 0.62 & 78.43 & 0.57 & 139.39 & 1.01 & 106.50 & 0.77 & 137.03 & 1.00 \\ FT20L70 & 147.48 & 94.47 & 0.64 & 87.37 & 0.59 & 153.69 & 1.04 & 118.12 & 0.80 & 150.39 & 1.02 \\ FT20L77 & 153.59 & 100.98 & 0.66 & 93.63 & 0.61 & 163.70 & 1.07 & 126.26 & 0.82 & 159.75 & 1.04 \\ FT30L20 & 102.86 & 60.39 & 0.59 & 55.04 & 0.54 & 97.67 & 0.95 & 75.50 & 0.73 & 100.29 & 0.97 \\ FT30L30 & 171.24 & 69.68 & 0.59 & 63.98 & 0.55 & 111.97 & 0.96 & 87.12 & 0.74 & 113.65 & 0.97 \\ FT30L40 & 130.57 & 78.98 & 0.60 & 72.93 & 0.56 & 126.27 & 0.97 & 98.74 & 0.76 & 127.02 & 0.97 \\ FT30L45 & 135.84 & 83.62 & 0.62 & 77.40 & 0.57 & 133.42 & 0.98 & 104.55 & 0.77 & 133.70 & 0.98 \\ FT30L60 & 151.15 & 97.56 & 0.65 & 90.81 & 0.60 & 154.87 & 1.02 & 121.98 & 0.81 & 153.75 & 1.02 \\ FT30L65 & 156.08 & 102.21 & 0.65 & 95.28 & 0.61 & 162.02 & 1.04 & 127.79 & 0.82 & 160.43 & 1.03 \\ FT30L68 & 158.94 & 105.00 & 0.66 & 97.97 & 0.62 & 166.31 & 1.05 & 131.28 & 0.83 & 164.44 & 1.03 \\ FT40L20 & 116.74 & 72.77 & 0.62 & 67.42 & 0.58 & 113.15 & 0.97 & 90.98 & 0.78 & 117.01 & 1.03 \\ FT40L30 & 130.87 & 82.07 & 0.63 & 76.37 & 0.58 & 127.45 & 0.97 & 102.60 & 0.78 & 130.37 & 1.00 \\ FT40L40 & 143.46 & 91.36 & 0.64 & 85.31 & 0.59 & 141.75 & 0.99 & 114.22 & 0.80 & 143.74 & 1.00 \\ FT40L50 & 153.25 & 100.65 & 0.66 & 94.25 & 0.62 & 156.05 & 1.02 & 125.84 & 0.82 & 157.10 & 1.03 \\ FT40L60 & 162.17 & 109.95 & 0.68 & 103.20 & 0.64 & 170.35 & 1.05 & 137.46 & 0.85 & 170.47 & 1.05 \\ FT40L62 & 164.12 & 111.81 & 0.68 & 104.99 & 0.64 & 173.21 & 1.06 & 139.79 & 0.85 & 173.14 & 1.05 \\ Mean & - & 0.62 & - & 0.58 & - & 1.00 & - & 0.78 & - & 1.00 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Strength comparison of analysis result and design prediction.  
Figure 9: Typical block shear fracture path in welded connection.  
stress distributions extracted from Path 3 and Path 4 of Figure 8a and the concept of triaxial stress of ductile fractured steel according to the von Mises yield criterion.