cylinder with convex endcaps?

On May 16, 2014, at 6:28 AM, 'Combs, Mike' mikecombs@... [spacesettlers] wrote:

>
> I think youre right about the stress at the seams. Another issue is that in the existing design, every part of the endcap is in tension. With convex endcaps, every part of it would be under compression. And all building materials are stronger in tension than under compression.
>
Not quite. Concrete is strongest under compression (Ive been told).

> Thats also one of the reasons why designing structures for space habitats might always be easier than structures for habitats on the ocean floor.
>
> Regards,
>
> Mike Combs
>
> From: spacesettlers@yahoogroups.com [mailto:spacesettlers@yahoogroups.com]
> Sent: Thursday, May 15, 2014 9:48 PM
> To: spacesettlers@yahoogroups.com
> Subject: [spacesettlers] cylinder with convex endcaps?
>
> Does it make any sense at all for a pressurized cylinder (space habitat)
> to have hemispherical endcaps that extend into the cylinder, instead of out?
>
> I've certainly never seen a balloon shaped that way... it seems like the
> forces trying to burst that shape at the seams would be tremendous. I
> also can't think of much reason such a shape would be particularly
> desirable.
>
> But before I dismiss the possibility entirely, I thought I'd check here.
> Can anybody think of a reason such a shape wouldn't be silly?
>
> Thanks,
> - Joe
>

mikecombs@...
[spacesettlers] <
spacesettlers@yahoogroups.com
> wrote:
I think youre right about the stress at the seams. Another issue is that in the existing design, every part of the endcap is in tension. With convex endcaps, every part of it would be under compression. And all building materials are stronger in tension than under compression.

Not quite. Concrete is strongest under compression (Ive been told).
Thats also one of the reasons why designing structures for space habitats might always be easier than structures for habitats on the ocean floor.

Regards,
Mike Combs

From:

spacesettlers@yahoogroups.com

[
mailto:spacesettlers@yahoogroups.com
]

Sent:

Thursday, May 15, 2014 9:48 PM
To:

spacesettlers@yahoogroups.com
Subject:

[spacesettlers] cylinder with convex endcaps?

Does it make any sense at all for a pressurized cylinder (space habitat)

to have hemispherical endcaps that extend into the cylinder, instead of out?
I've certainly never seen a balloon shaped that way... it seems like the

forces trying to burst that shape at the seams would be tremendous. I

also can't think of much reason such a shape would be particularly

desirable.
But before I dismiss the possibility entirely, I thought I'd check here.

Can anybody think of a reason such a shape wouldn't be silly?
Thanks,
- Joe