Hi, I've been working on a tubular sub frame, that I want to attach to a main frame. The attached shows the sub frame in black lines. The main fram is in purple. There are only four connection points and a force pushing down on each side. When I check for the reaction forces and make the shear/moment diagram, do I want to use the full 43" to make it? or do I tackle it by making a shear/moment diagram for the 18" part and then tranfer those forces to the cross members? and then transfer again to the other cross members? If the later is the correct way, the angled beam to the bolted joint; the reaction force of the orginal force tranfers over, do you treat this like a cantiliver beam? Thanks.