Unequal angle with fillet welds, 150 kN

Given: working tension 150 kN → factored $T_u=1.5\times150=225$ kN; fillet welds; $f_y=250$, $f_u=410$ N/mm².

Section

$A_g\ge\dfrac{225\times10^3\times1.10}{250}=990$ mm². Try ISA 100×75×8 ($A_g=1336$ mm²), long leg connected, centroid 31.5 mm from the heel.

• $T_{dg}=\dfrac{1336\times250}{1.10}\times10^{-3}=303.6$ kN $>225$ ✓

Weld

• $s=6$ mm (angle 8 mm: min 3-5 mm, max 6.5 mm). Shop weld, $f_{wd}=\dfrac{410}{\sqrt3\times1.25}=189.4$ N/mm².
• Strength per mm $=189.4\times0.7\times6=795.4$ N/mm.
• Total length $L_w=\dfrac{225\times10^3}{795.4}=282.9$ mm.
• For no eccentricity: toe weld $L_1=L_w\times\dfrac{31.5}{100}=89.1$ mm; heel weld $L_2=193.8$ mm.
• Adding $2s=12$ mm for end craters: toe 105 mm and heel 210 mm.

Rupture check (shear lag; welded, so $b_s=w=75$ mm; conservatively $L_c=89$ mm)

$\beta=1.4-0.076\times\dfrac{75}{8}\times\dfrac{250}{410}\times\dfrac{75}{89}=1.034$

$$T_{dn}=\frac{0.9\times(100-4)\times8\times410}{1.25}+\frac{\beta\times(75-4)\times8\times250}{1.10}=360.2\ \text{kN}>225\ \checkmark$$

Answer: ISA 100×75×8, 6 mm fillet welds; toe weld 105 mm and heel weld 210 mm.