Re: Another Trick

>However, if the effect of significant wall thickness is added then I am
>unsure, and would think some secondary stress could possibly be generated.
>However I have difficulty in visualising the effect. A finite element study
>would put my mind at rest.

God only knows why I'm doing this on a gorgeous Saturday afternoon, but I made a quick FEA run on an L-shaped pipe run with a long radius ell and there was no rotation. Uniform temperature throughout so the thermal strain was uniform. Everything changed scale uniformly since the thermal strain was equal. The pipes didn't go oval either. Anyone want pictures or details, let me know.

Answering my own post, I see I wasn't the only one who fell for it.

In a similar vein, Suppose you have a hole in the middle of a square plate and the plate is heated to a uniform temperature. Does the hole get larger or smaller?

Christopher Wright P.E.    |"They couldn't hit an elephant from
chrisw@skypoint.com        | this distance"   (last words of Gen.
___________________________| John Sedgwick, Spotsylvania 1864)