A neighbor who used to work for Albert Eisentraut sent me this link to a recent technical paper about the influence of tube selection on frame stiffness. The link is to a 311 kB pdf file.
Parametric finite element analysis of steel bicycle frames: the influence of tube selection on frame stiffness
I found it pretty interesting.
Beam element sectional properties for top tube, down tube, seat tube, seat stays, and chain stays were taken from the tube profiles published by the manufacturers Reynolds (953, 853, 725, 631, 525 tubes), Columbus (XCR, Spirit, Life, Zona tubes) and Tange (Superlight, Ultra Strong, Infinity tubes).