Beam Reinforcement Calculation 2

[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.

 

[human909]

This "diatribe" is relevant as it goes to the core of the original question.

The longitudinal shear flow between the plates and the I beam would be zero. All you need to do to have them act as a compositive section is to sister them together. So bolts or spot welds at the centroid would be sufficient.

 

[BAretired]

This "diatribe" is relevant as it goes to the core of the original question.

The longitudinal shear flow between the plates and the I beam would be zero. All you need to do to have them act as a composite section is to sister them together. So bolts or spot welds at the centroid would be sufficient.

Shear flow between the I-beam and plates is not zero. Depending on the thickness of side plates, it may actually reduce the shear stress in the beam web for the height of side plates, but that is a questionable advantage since the shear stress in the remainder of the web remains the same as it was without side plates. So I see your point...side plates as shown in the original post are not useful. To sister the side plates is equally useless, so why not simply do nothing? Leave the I-beam alone.