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it. Before you call the funny farm to come and get me, let me explain why this weakening can happen.
If we imagine a boss with no gussets having a side load applied at the top (farthest from the wall to which the boss is attached), it can be seen that there's a lot of stress occurring at the boss-to-wall junction. The junction is small, compared to the size of the boss.
If we now go to the other extreme, and reinforce the wall with a conical section all the way around the boss, (like a great, big, solid gusset) we spread the stress over a large area and dramatically enhance the strength of the part in that area. Obviously, though, there's a problem: we've used a huge amount of material, relatively speaking, and the sink on the outside of the part is going to be maximum ugly. The obvious choice is to take away some of the material in the conical section by separating it into sections, kind of like an orange, only with parallel walls.
As long as we have, let's say, eight sections, the stress will still be pretty much spread and shared among the gussets. If, on the other hand, we reduce the number of sections to four or less, the contact points where the gussets join the wall don't receive much mutual support from the other gussets (they're too far away) and the stress is concentrated in a very small area. This stress concentration is what will reduce the strength of the boss and weaken its resistance to side loading.
And there you have it: We're much better off if we use more, thinner gussets (to keep sink to a minimum) rather than fewer, thicker gussets. There may be reasons I should be taken to the funny farm, but gussets isn't one of them.
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