bearing of pipe through 2x4

[tfloyd]

I am trying to calculated the allowable capacity of a 1.3" outer diameter pipe that runs through the center of a 2x4 and loaded perpendicular to the grain (2x4 spans between pipes which support the uniform load on the 2x4). Anyone know where an equation for this can be found?

 

[focuseng]

AF&PA National Design Specification. Section on bearing capacity. Dowel bearing equations do not apply to something this big typically. Depends on the stiffness of the pipe too I guess. I think the dowel bearing equations are valid only up to 1" dia. AND this is not a connection of two members so the yield modes are not applicable to a single member. The theory may be applicable but the equations are mostly empirical so I don't think I could trust them for simulating the yielding of a pipe that starts to bend. You will also need to check tearout/block shear using same source found in appendix.

MAP

 

[tfloyd]

These equations do not seam to consider how close the pipe is to the edge. In this case there is only about 1" of wood between the pipe and the edge of the 2x4. I think splitting the wood along the grain will still be the failure mode, but I would think that this would be made easier when the edge distance is small.

 

[focuseng]

Yes, you will need to consider block shear and tearout failures from the appendix. Also you can consider the V of the reduced section on the bearing side only. Other area which might help in your situation is the notched end bearing equations -not quite exactly but you are doing something which the code is not really set up for so you must improvise and have some rational engineering basis for you reasoning. Then apply some safety factors. I don't believe you will find a magic equation for your describe situation.

MAP

 

[tfloyd]

Thanks, I took your suggestion.