Hi,
I have modeled knee braced frame as shown in imahe below. I am looking at the controlling axial load using member force envelope graphical mode. I see the values for min = -16.54 and max 3.21k. Therefore min value should control. However, when I check the beam design result report, the axial force is considered as 3.21k. But this value is not the controlling axial force.
Is there a reason for controlling axial force not being considered? below are the 3 images that shows axial force
I can upload the model if needed.
Thanks,
Presumably because 3.2 kips of compression along with the bending moments, unbraced length and Cb factor in the center section yields a higher interaction ratio than 16.5 kips of tension in the shorter segment. You can isolate a single load combination in the Ram Frame Steel mode and recheck the report if needed.