Weld Strength Calculator (Eurocode 3 / AWS D1.1)

Calculate fillet and groove weld throat shear stress, effective weld length, and design resistance per Eurocode 3 (EN 1993-1-8) and AWS D1.1.

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▸Formula · assumptions · example(Eurocode 3 (EN 1993-1-8) · AWS D1.1 (Structural Steel) · AWS D1.2 (Structural Aluminum))

Formula

\tau_w = \frac{F}{\sqrt{2} \cdot a \cdot L_w} \le f_{vw,d} = \frac{f_u / \sqrt{3}}{\beta_w \cdot \gamma_{M2}}

Eurocode 3 (EN 1993-1-8) / AWS D1.1 fillet weld throat thickness a, effective weld length Lw, and design shear resistance.

Assumptions

  • · Effective throat thickness a calculated as nominal leg size s × 0.707 for 90° fillet joints
  • · End start/stop crater losses subtracted from total weld run length (Leff = L - 2a)
  • · Correlation factor βw assigned according to steel grade (e.g. βw = 0.80 for S235, 0.85 for S275, 0.90 for S355)

Worked example

Worked example — Lap Joint Fillet Weld (F = 60 kN, leg size s = 6 mm, L = 120 mm, S275 Steel)

Throat a = 4.24 mm, effective length Leff = 111.5 mm. Weld stress τw = 127.1 MPa (well below design limit fvw,d = 208.5 MPa).