RAM Connection - Moment End Plate Beam Splice

Question

Using RAM Connection to design a moment end plate beam splice which is flush on one end and extended downwards (MEP BS Extended downwards). When the program calculates the web weld shear strength, it only uses half of the weld length. When calculating Aw for a W14X43, for example, the program uses 5.73 in. for the weld length rather than the full weld length along the full depth of the web. I can not find anything in applicable codes to justify the use of the reduced value. Am I missing something?

Seth Guthrie · Accepted Answer

I believe this comes from AISC Design Guide 4, Section 2.1 paragraph 8: 
 Only the web to end plate weld between the mid-depth of the beam and the inside face of the beam compression flange may be used to resist the beam shear. This assumption is based on engineering judgment; literature is not available to substantiate or contradict this assumption. 
 Design Guide 16, page 12 makes a similar point.