First point to remember, the figure is applicable to tubular connections. Next I believe "E" refers to the weld size. However, the letter "E' is also used in the equation in clause 2.25.2.2 where it stands for Modulus of Elasticity. However, that makes no sense if you try to plug the value of 29 million into the functions listed in Figure 3.2. Back to the weld size: in the case of the fillet weld, the size "E" is the Effective Throat, which in reality is the Theoretical Throat because no credit is given for fusion beyond the root or convexity of the weld face. This is just another case where it would be nice if the various committees would stick with standard AWS terminology to reduce the confusion.
Figure 3.2 defines the minimum leg length of the prequalified fillet welds used to join members in the T, , and K configurations. The letter "L" is the length of the fillet leg. Since we are addressing tubular connections, the joint configuration changes as you move around the joint. In each case the leg dimension is determined by the dihedral angle between the members at the toe, side, or heel of the joint. The weld size varies as you traverse the circumference of the joint.
Both the conditions set forth in clause 2.4.3 and Figure 3.2 must be considered when sizing the actual weld. The designer has to jump through a series of hoops to derive the proper weld size when dealing with prequalified fillets (or grooves) between tubular members. It begins with the Engineer (structural) specifies the leg or the throat of the fillet weld in accordance with 2.4.3 based on "strength requirements. Then the actual weld size is determined based on the location, i.e., heel, side, or toe and the dihedral angle at the specific location. I guess the detailer would listed the larger value if there is a discrepancy between the two values, i.e., clause 2.4.3 and Figure 3.2.
Confusing is an understatement. Maybe that is why I have never seen a T, Y, or K joint detailed in accordance with AWS D1.1 requirements. If the designers cannot tell the difference between a fillet weld and a groove weld, how are they expected to know how to detail a prequalified T, Y, or K?
Best regards - Al
What is your thoughts on the 3 different coulmns? E = 0.7t, E = t and E =1.07t, not sure which coulmn to apply and when, I understand or I think I do that t (thinnest member) x 1.5 per say equals the theoretical but lost at when to apply 0.7, t or 1.07 if this makes since regarding my question. The real pain comes from detailing to me not doing their job on joint geometry on drawings and leaving it to QC to make sure it's preped correct per code, But to be honest , AWS D1.1 Clause 2 regarding TYK is tough on me on required joint included angles versus dihedral angle, but this is my fault do to not enough education. To be safe in the Toe Zone I will use a 90 degree on all fillets and bring the bottom leg out for smooth transisition on all thickness of HSS tube in step box connections.
I feel like thier is differences between a CWI and Weld Engineers, But some companys think a CWI can interpret all of Clause 2 and apply the theory, I think I'm close to being on the right track but can't leave nothing to chance on procedures, I want to know they are correct. thanks RS
I revised my response. Maybe it will make more sense now.
It is not the CWI's responsibility to fill the roles of the Engineer or the designer. This puts the CWI in a sticky situation, because the inspector most likely has no idea what the design assumptions are or whether the connection is properly designing with D1.1 in mind. However, it is to the CWI's benefit if he can question the weld size and ask the Engineer what he had in mind and whether the requirements of Part D of Clause 2 were met.
The columns E=0.7t, E=t, and E=1.07 are defined in clause 2.25.1.3. The column used is dependent on the Engineer's design assumptions, i.e., whether the design is based on elastic design or ultimate strength design. The third column is when neither ASD or LFRD is applicable. This is beyond the capability of most CWIs to determine.
The column E-0.7t is based in part on Annex B. Annex B is used to size the fillet weld for angles other than 90 degrees. In other words, the Engineer provides the fillet leg dimension on his structural design drawings based on strength requirements. The detailer uses Annex B to resize the fillet weld based on the actual angle between the two members. In Figure 3.2 the column marked E=0.7t is similar, but it is based on the thickness of the thinner member (t) rather than the Engineer's weld size (based on strength). In most cases I expect the minimum weld size based on Figure 3.2 to be larger than the fillet weld size required by "strength" calculations.
Again, the table is simply defining the minimum size of the prequalified fillet weld in a tubular connection.
Best regards - Al
Al, Thank You, this helped ALOT
RS
Happy to help.
Best regards - Al
Topic American Welding Society Services / Technical Standards & Publications / AWS D1.1, Figure 3.2 (2010)
