<html><head></head><body><p dir="ltr">Hank, any chance you can find out what the alloy is? This will have a profound effect on its efficacy.</p>
<p dir="ltr">Sean<br>
</p>
<br><br><div class="gmail_quote">On January 10, 2015 11:51:22 AM MST, hank pronk via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<pre class="k9mail"><br />Sean, <br />Thank you, that is helpful. My idea was to make the insert as tight as possible (sweat it in) I am not sure if the difference in material would cause a problem though. The idea of seating the port into the shell a good option also. I am just chewing the fat here, I have enough on my plate but it is fun to think about. I was wrong about the size, the sphere is 6 feet and I wrote 60 in. I imagine that kills the rating quite a bit?<br />Hank<hr /><br />On Sat, 1/10/15, Sean T. Stevenson via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br /><br /> Subject: Re: [PSUBS-MAILIST] bolt in penetration<br /> To: "Personal Submersibles General Discussion" <personal_submersibles@psubs.org><br /> Received: Saturday, January 10, 2015, 1:40 PM<br /> <br /> You could certainly do that, although a three inch<br /> thick shell is pretty substantial - I might consider<br /> machining eg. conical window seats in the hull shell<br
/> directly, and then derating the hull to a depth whereby the<br /> actual hull thickness is the effective derated thickness<br /> plus the effective reinforcement, which just happens to be a<br /> contiguous shell. The bolt-in arrangement would not act as<br /> hull reinforcement though - unless it was a force fit in the<br /> hole. The idea of reinforcements around openings is to<br /> provide material around the hole to carry the shell hoop<br /> stresses that would otherwise have passed through the<br /> material in the opening, such that you don't increase<br /> the nominal shell stress. This requires a (relatively)<br /> smooth load path to redirect stress around the hole. Brian<br /> recently asked me about the effectiveness of reinforcements<br /> like perpendicular flanges lining the hole, and this is a<br /> bit complicated, because some stress i!<br /> s indeed<br /> redirected into such a flange, but the load is not evenly<br /> distributed as you move inboard or
outboard away from the<br /> hull shell (with diminishing returns at increasing<br /> distances), and you also introduce a stress concentration at<br /> the perpendicular transition. Ideally, reinforcements should<br /> be an effective thickening of the hull in the region<br /> immediately adjacent to the opening, tapered smoothly back<br /> (something like 4:1) into the hull shell to provide a<br /> continuous load path with no stress concentrations at abrupt<br /> changes in geometry.<br /> Sean<br /> <br /> <br /> <br /> <br /> On January 10, 2015 8:25:39<br /> AM MST, hank pronk via Personal_Submersibles<br /> <personal_submersibles@psubs.org> wrote:<br /> Is it feasible to have a<br /> bolt in penetration in a 3 inch thick sphere hull. I am<br /> picturing machining a hole in the hull, then inserting a<br /> window housing with a shoulder(flange) that fits tight in<br /> the hole and is bolted in place. Can that arrangement act<br /> as reinforcement for the hull.<br />
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