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Politics : Formerly About Advanced Micro Devices -- Ignore unavailable to you. Want to Upgrade?

To: tbolding who wrote (800835)	8/25/2014 5:11:04 PM
From: Bilow	Respond to of 1583406

Hi tbolding; Re: "1. How do fragments from a blast create perfectly round holes?"; First, the notation is that "fragment" is one of the deliberately designed pieces of metal that come from right next to the warhead. They're fairly heavy pieces of metal that are intended to destroy aircraft at some distance. When a fragment hits the aircraft it's going considerably faster than a rifle bullet, about 5000 feet per second. The tip of the fragment and the aircraft ends up starting a "crater". Regardless of the shape of the fragment, the craters they make tend to be circular. That said, some communist anti-aircraft warheads use spherical steel balls. For example, see: dtic.mil Re: "2. How does blast from a missiles create both entrance and exist holes from on the same side? Were there two missile blasts?" If the aircraft has several layers of skin, each layer makes its own crater. The crater material flows perpendicular and out of the aircraft. I think what you see as outward bent plates got bent that way from the cratering effect on an internal layer. Go back and look at the photo again. Ah heck, I'll reproduce it here: Now instead of thinking about "bent out" versus "bent in", look only at the inner layer only. Is it bent out or in? Now look at the outer (painted) layer, is it bent out or bent in? If you see it as I did, you will say that the inner layer always seems to be bent in. The outer layer is bent out in places where there is an inner layer visible and is bent in in the places where there is no inner layer. That's consistent with the outer layer being bent out by the cratering of the inner layer. Here's an unclassified military article on the craters that form when high velocity fragments hit aluminum. In particular, look at figure 2: dtic.mil Now the above situation is different in that the fragments are likely of much denser and harder material than the aluminum aircraft parts. -- Carl