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Within SCIA Engineer there is a possibility to choose from three methods for determination of the flange weld sizes by modifying the Weld size determination parameter in the connection setup.
The default calculation of flange weld size is based on the Ref. [35] - ECCS N° 126. The final formula is derived as:
with
The weld size af is designed according to the resistance of the joint. The design force in the beam flange can be estimated as:
with:
| FRd | the design force in the beam flange |
| Mj,Rd | the design moment resistance of the connection |
| h | the lever arm of the connected beam |
The design resistance of the weld Fw should be greater than the flange force FRd, multiplied by a factor α. The value of the factor α is specified in the Ref. [34] - EN 1993-1-8, Art 6.2.3 (5).
α = 1.7 for sway frames (braced)
α = 1.4 for all other frames (unbraced)
However, in no case should the weld design resistance exceed the design plastic resistance of the beam flange Nt.Rd :
with:
| bf | the width of a beam flange |
| tfb | the thickness of a beam flange |
| fyb | the yield strength of the beam material |
Dimensions of the smaller flange are used in the calculation.
The final design resistance of the weld Fw should be taken as smaller of: α*FRd and Nt.Rd.
The weld size design for af, using Ref.[32] - EN 1993-1-8 Art. 4.5.3 and Ref.[35] - ECCS N° 126:
with.
| Fw | the design resistance of the weld |
| bf | the width of a beam flange |
| fu | the ultimate tensile strength of the weaker part |
| βW | the correlation factor |
| γM2 | the partial safety factor for welds |
The weld size af is then designed similarly as in the prevous method (See also chapter: "Calculated from connection resistance"), with the only difference that resistance Fw is taken as minimum of the above and force F obtained from the internal forces present in the connection. The force is calculated as:
