Below is an image of a bolted beam splice connection that I'm working on.
RAM Connection considers the eccentricity of the bolt group to be 3.125in and the coefficient for eccentrically loaded bolt groups to be 8.
I believe that the eccentricity should be 6.25in and the coefficient should be approximately 3.5 (Table 7-7 from AISC360 15th edition; there isn't even an 8 option on this table given the parameters). Why does RAM connection select such a high coefficient for eccentrically loaded bolt groups? Why doesn't RAM consider eccentricity of the bolt group to be related to the adjacent bolt group?
Thanks
What version are you using? I checked a beam splice like this in 13.09.00.163 using AISC 360-16 LRFD and my C value (e.g. for bolt shear) is 5.45 which matches what I get from the table 7-7 using the 3.25" e and n=4. If you have any good example from AISC that clarifies the eccentricity location we can take another look at that.
I figured it out - after applying a load, RAM returned a C value of 5.45. That begs the question why RAM considers e to be the horizontal distance from the center of one of the bolt groups to the center of the splice plate. I guess that's more of a statics question.
Thank you for your help!
The zero load thing make sense, because we need the load vector angle to get into the C calculation.
My initial thought on the eccentricity is that the connection is (usually) symmetric and flange plates are expected to take any actual moments so we can draw a free-body diagram of half the connection from the CL of the splice with only shear forces on the cut.