Beam Reinforcement Calculation

[Nick6781]

Let's say I need to use a web plate instead of a flange cover plate (I know...) to reinforce a beam. How do I calculate the required weld to ensure the section acts compositely? The shear flow equation gives the shear along a horizontal plane, but in this case, the faying surface is vertical. I can't quite wrap my head around it.

 

[jerseyshore]

Is this for repairing a corroded beam or reinforcing it for an increased shear load? If it's purely for bending, the increase in capacity here is going to be small so I can't imagine it's even worth it. When the centers line up shear flow is greatly simplified. You just have to design the connection to take the shear at any particular point. Then when the reinforcing ends, you have to get the shear back into the original member to transfer it out to the supporting column, bearing wall, etc.

 

[skeletron]

Size the weld to develop the capacity of the plate in shear.

 

[aalmasri]

Using web plate helps in resisting shear stresses mainly, while using flange cover plate helps in resisting mainly bending stress, so basically you cant use one instead of the other. Everyone has its own use. Be careful.
You can calculate how much shear the additional web plates can carry, and design your weld based on that.

 

[jhnblgr]

Likely cheaper to replace the beam. Need more background on what the actual issue is

 

[DaveAtkins]

I would use the shear flow formula, VQ/I, to determine the load per lineal foot in the weld. Then design the weld accordingly.