Potential Error for Tensile Rupture on a WT section in RAM Connection

Question

I was running a design for a WT vertical brace and found what I believe to be a mistake in the calculation of the shear lag factor, U, for tensile rupture. I have (7) rows of bolts connecting the WT flange to the gusset. From AISC Table D3.1 I would expect my shear lag factor to be the larger of Case 2 (U=1-x_bar/L) or flange portion of Case 7 (U=0.9). 
 However, it appears that for Case 2, the x_bar being used in the program is not the distance from the faying surface at the flange to the centroid of the member as expected. Rather, it is using the distance from the geometric center (depth/2) of the section to the centroid. Unless I am missing something, the distance from the geometric center to the centroid is arbitrary in this case and the distance from the faying surface to the centroid should be used. 
 For Case 7 it also appears that it is using the web connected case (U-0.7) instead of the flange connected case (U=0.9). 
 
 Is there any guidance on how I should interpret these results? Has anyone else run into this issue? 
 
 Note: I am using Connection Standalone Version 10.0.0.177

F_Diego · Accepted Answer

Hello Taylor. Unfortunately you are right. You found a bug in the way the software is calculating the Shear Lag Factor for Directly Bolted Tee brace sections. We have fixed this and it will be available for you in an update soon. Thank you very much!

Karl G · Answer

I will log this as a defect and alert the development team. The connection associated with this issue is shown below: 
 
 The brace is a WT 7x30.5 and I see the same x_bar is used for the case where the brace is oriented at 90 degrees and connected to the flange (as shown above) and for the case where the brace is oriented at 0 degrees and connected to the web. 
 The x-bar appears to be calculated based on the angle shape remaining after the WT is split in half. U is calculated assuming the WT is always connected to the web. The 90 degree rotation of the brace does not appear to be recognized by the program. 
 In my tests, I used a WT brace oriented at 0 degrees and connected to the gusset using claw angles. In this case, the program is using the correct x-bar and U when designing the brace. 
 Thank you for bringing this to our attention.