In contrast to the older German steel code DIN 18800-1, the Eurocode for steel design defines an effective length of a fillet weld as follows (no sketch is provided in the Eurocode):
"The effective length of a fillet weld should be taken as the overall length of the full-size fillet, including end returns. Provided that the weld is full size throughout this length, no reduction in effective length need be made for either the start or the termination of the weld."
In literature, e.g "Bemessungsbeispiele im Stahlbau nach Eurocode 3" by Ioannis Vayas, the fillet weld goes around a corner "a bit" (L-shaped) hence the straight length of the fillet weld is equal to the effective length.
In "Static and strengths of materials" by Chegg, for the same example, the full length (straight fillet weld + a bit around the corner) is considered as the fillet weld length.
(This was an example, unfortunately, there are plenty of contradictions).
The general problem is that the interpretation based on EN 1993-1-8 is unclear.
The reason of this design rule - is unclear.
Regarding the size of the fillet weld: At the start of a fillet weld, a weld bead has a "indentation" and at the end of it, it has a weld material accumulation. This imperfections change the effective throat cross section (Of course, a full sized fillet weld consists of many weld beads). However, it is not clear if this plays a role in this case.
Further, stress peaks at the edge of the weld leg (interface to the fusion zone) at the start or end of a fillet weld appear especially under dynamic loads.
I assume that residual stress from welding does not play a role.
For now, I want to ask (1) why this rule was introduced and (2) how to apply it properly
https://www.phd.eng.br/wp-content/uploads/2015/12/en.1993.1.8.2005-1.pdf
https://www.phd.eng.br/wp-content/uploads/2015/12/en.1993.1.8.2005-1.pdf
https://eurocodes.jrc.ec.europa.eu/doc/2014_07_WS_Steel/presentations/06_Eurocodes_Steel_Workshop_WALD.pdf
http://www.dica.unict.it/users/aghersi/Testi/Normativa_Europea/EN%201993-1-8.pdf
Hussam Ali Mohammed thank you for your link to the Eurocode 1993-8 which can help others in understanding the question in case of interest.
Regarding your link to the Eurocode workshop from František Wald:
The slide with the title "Two fillet welds in parallel shear" does not answer how the weld length is obtained (without explanation) - it is just the geometric length; but an explanation on how the weld length is determined is missing; (a) in case if it is non-continous, (b) if it has a kink, does (a) or (b) or both in combination affect the length?
The slide with the title "Connection of cantilever" does not answer how the minimum weld length criterion is treated- e.g. for an IPE 140, there is namely the problem for an a=6 mm weld (max weld thickness) that at the lower side of the flange, the minimum weld criterion is not fulfilled (in case the weld along the perimeter of the I-beam is non-continous and the Eurocode interpretation is conservative due to missing clarity ) which does not make sense for a standardized product. This conflict e.g. must become naturally disentangled by understanding the weld length calculation acc. EC 1993-8.
- Badges
- Science topic
- Similar topics
- Engineering
- Civil Engineering