A project that confuses me. A rod towards the front?
When sitting or standing on it, all of the forces will be the same as if the top was fastened directly to the sides as with typical construction. The only difference is that a force on the front edge, in this case, is transmitted to the rear "beam" and then via the connection of the "beam" to the sides. This is what a cantilever does. There is nothing unstable about it so long as the individual members are strong enough to transmit the loads without breaking.It probably makes a nice piece, but tipping or standing on it not so much..
Again. Your concern about the strength of individual members may be legitimate. That does not mean the whole piece is unstable. Assuming sufficient strength and stiffness of all members, all loads are going to be transmitted to the same points on the floor. If the "ribs" extended beyond the front edge of the side vertical supports, then you might have stability concerns.If 300 pound mama uses it to hang a picture and steps on only one, this concerns me. It's not distributed...
I was looking at functional without concern.
My two cents but me thinks that is something to look at and not something to really be used. The bench down at the park looks more comfortable to sit in. Regardless, a great looking design.There are stability concerns.
A piece like this may be viewed
A piece maybe be used
A piece may be abused.
Being a former furniture maker I have to look at everything..