x_bar is the distance between the centroid of the connected element and the plane of the connection. "L" is the length over which the connection takes place. The idea is to take account of the fact that forces transmitted to only some parts of a tension member take some time to work their way into the entire member. If you haven't done so already, you should read up on:
1) Commentary section D3 of the AISC steel manual and:
2) Google "Whitmore section".
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
are you talking about a specific code ? (what the heck is X' ??)
i found this on the AISC site ...
"5.3.4. What is shear lag and when must it be considered?
Shear lag describes behavior at an end connection of a tension member where some but not all of the cross-sectional elements are connected; the area that is effective in resisting tension may be less than the full calculated net area. Procedures for treatment of shear lag and determination of the effective net area in bolted and welded connections are provided in the 2005 AISC Specification Section D3.3. Alternatively, shear lag concerns can be addressed by selecting a connection length that mobilizes the entire load-transmitting capability."
another day in paradise, or is paradise one day closer ?
If you read that AISC section that I mentioned above, you will find that it came from statistical correlation with "some 1,000 bolted and riveted connection test specimens".
The greatest trick that bond stress ever pulled was convincing the world it didn't exist.
