Combined Stresses In Weld Joint Of Flange And Web
Combined Stresses In Weld Joint Of Flange And Web
(OP)
IN PLATE GIRDER DESIGN OF WELD JOINT BETWEEN WEB AND FLANGE,VARIOUS STANDARDS AND BOOKS LIKE GAYLORD,MUKHONOV ETC REQUIRE THE JOINT TO BE CHECKED FOR ONLY SHEAR FLOW AND VERTICAL SHEAR DUE TO ANY CONCENTRATED LOAD FROM FLANGE TO WEB(IN CASE WEB IS NOT MILLED ).MY DOUBT IS THAT THE WELD WILL ALSO BEND IN THE SAME RADIUS OF CURVATURE AS THE WEB TOP OR FLANGE'S WEB SIDE SURFACE. SO BENDING STRESSES SHOULD BE INTRODUCED IN WELD AS WELL.SO WE SHOULD CHECK THE WELD FOR COMBINED BENDING AND SHEAR STRESSES.BUT THIS IS NOT REQUIRED AS PER STANDARDS. I GUESS I HAVE GOT IT WRONG SOMEWHERE BUT CAN'T FIGURE IT OUT. CAN ANYONE PLEASE ENLIGHTEN ME ON IT AND SUGGEST SOME REFERENCE?






RE: Combined Stresses In Weld Joint Of Flange And Web
the beam bends but the RFT bars suffers a tension force only and not bending..
the flange plate bends while attached to the web plate so they bend together...what prevent slippage between them is the friction force between them that is transfered through the weld as a shear force parallel to the flange plane (that's called the shear flow)
RE: Combined Stresses In Weld Joint Of Flange And Web
RE: Combined Stresses In Weld Joint Of Flange And Web
RE: Combined Stresses In Weld Joint Of Flange And Web
As you say, the whole section takes on a curve due to the bending action, and the weld takes on the same curve, causing some bending in the weld. The bending stress, however, is very small compared to the shear stress and the codes ignore it.
RE: Combined Stresses In Weld Joint Of Flange And Web
The theory behind designing the weld should be the same as finding out the number of studs needed to make a composite connection for a composite member. This theory calculates the capacity needed from the bending moment.
RE: Combined Stresses In Weld Joint Of Flange And Web
While it's true that the shear flow can be calculated from the bending moment, it's not because the weld is resisting bending moment. The weld is resisting the shear flow at the section, which is a function of the shear at the section.
RE: Combined Stresses In Weld Joint Of Flange And Web
the shear flow = Q.S/2I.b
Q=max shear on that beam
S=first moment of area of the flange plate about the beam's horizontal axis
I=moment of inertia of the C.S
b=web plate's thickness