Besides the obvious exceptions of the Stone Tortoise and Omega Shell, I was under the impression that all shields of a certain star rank shared their total health, ergo a Volcanic Plate has as much health as a Barbarous Thorn which in turn has as much health as a Grey Owlite. Now it's never really mattered to me since when bombing I don't really need to shield and when not bombing I normally just use a Swiftstrike, but using different shields lately I've noticed that even when their defenses against a certain attack are equal, some shields still seem to break quicker than others which would imply that they actually do have varying amounts of health or at least the rate at which they regenerate it, and any and every thread I can find on the matter seems to concur with this.
So just for the sake of clarification do different shields actually have different amounts of health and among other things variations in regeneration time and distance of knockback when shield bumping and are there any established stats on these or do we just have a vague idea of which have more and less?
You can check the Wiki. With your previously mentioned exception it certainly seems that they all have about the same health/durability. Perhaps they weaken/break faster if they don't have as much resistance to the damage type currently being dealt to them. As for the other stats, I have no idea.