3465x
002930
2019-04-15

Question

A beam is welded with fillet welds to an end plate. How can I calculate the weld stresses?


Answer:
Image 01 shows a flexurally rigid beam connection using fillet welds. The cross-section of the beam is IPE 300, S235. There are the external flange fillet welds (a = 7 mm, l = 150 mm), the fillet welds along the inner side of the flanges (a = 5 mm, l = 50 mm), and the web double fillet welds (a = 4.5 mm, l = 239 mm). The bending moment acting on the connection is My = −106.11 kNm.
It is assumed that the fillet welds are concentrated in the root lines.

What follows is this:
A = 2 ∙ 0.7 ∙ 15 + 2 ∙ 0.45 ∙ 23.9 + 4 ∙ 0.5 ∙ 5.0 = 52.51 cm²
Iy = 2 ∙ 0.7 ∙ 15 ∙ 15.0² + 2 ∙ 0.45 ∙ 23.9³ / 12 + 4 ∙ 0.5 ∙ 5.0 ∙ (15 - 1.07)² = 7,690 cm4

At the end of the double fillet weld of the web, the following stress results:
σ = 10,611 / 7,690 ∙ 11.95 = 16.49 kN/cm²

The fillet welds are modeled in SHAPE‑THIN and entered as internal force My = −106.11 kNm. After the calculation, the same values are obtained in the calculation above (see Image 02).