Would someone from the military who wears a dress sword (which are so dull, they can barely chop butter) be allowed to carry it on him on Shabbat? Is it considered an ornament? It seems that that is the whole purpose. It isn't like other weapons, who have two purposes....war and ornamental.

you mean from an eruv point of view?

Yes.

What does this have to do with pshat on the Daf?

The gemara discusses tachshitin - ornaments that women wear. The question came up in the gemara about wearing your weapons, as that was considered an ornament, but the gemara found later that it was only an ornament during a time of peace; during wartime, it was a weapon in its fullest sense, and so since its not an ornament, it can't be worn.

R. Ovadyah Yoseph in Yechaveh Da'at 5:18.

For those of us who don't have that sefer, can you tell us what it says? Thanks.

See Arukh HaShulhan.