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Stress in fillet weld. Two conflicting sources for calculating shear stress
[FONT=Calibri][SIZE=3][COLOR=#000000]The problem is not complicated but two references provide the same equation but define the type of stress differently.[/COLOR][/SIZE][/FONT] See attached pdf
[FONT=Calibri][SIZE=3][COLOR=#000000]Actual project: A round shaft is fillet welded to a plate forming a cantilever. A tip load perpendicular to the shaft is applied. [/COLOR][/SIZE][/FONT]
[FONT=Calibri][SIZE=3][COLOR=#000000]Conflict: A textbook has an example of the above cantilever BUT with a moment applied at the free end. The provided stress formula = 5.66M/Pi(b)D^2. This stress is identified as the normal stress. The text continues that if the moment was created by an applied force (as is the case for my project) then the direct shear force would also be calculated F/A (A= throat area) and the stresses combined with vector addition to get Max shear. In that approach the normal force is divided by 2 then squared then added to the square of F/A (direct shear) then the square root of the sum taken.[/COLOR][/SIZE][/FONT]
[FONT=Calibri][SIZE=3][COLOR=#000000]In a chart from the American Welding Society (AWS) the same formula (5.66M/Pi(h)D^2) is provided for the applied moment at the free end BUT is identified as the shear stress vs. a normal stress. Since the actual problem is a point load at the free end I believe I must also address the direct shear. All I have is the AWS chart. If AWS suggests how to account for a point load vs. applied moment I don’t have that information[/COLOR][/SIZE][/FONT]
[FONT=Calibri][SIZE=3][COLOR=#000000]If I just accept the AWS as is I get a shear stress twice the text book approach and I have not adjusted for the fact that there is an applied force vs. moment.[/COLOR][/SIZE][/FONT]
[FONT=Calibri][SIZE=3][COLOR=#000000]I understand that with fillet welds the stress of concern is shear and taken through the throat of the weld.[/COLOR][/SIZE][/FONT]
[FONT=Calibri][SIZE=3][COLOR=#000000]Does the AWS bake in factor of safety? [/COLOR][/SIZE][/FONT]