The Column Strength of Two Extruded Aluminum-Alloy H-Sections
This is a 1939 NACA technical report from the National Advisory Committee for Aeronautics, issued through NASA's Technical Reports Server, on column buckling tests of extruded aluminum-alloy H-section struts for aircraft designers and engineers. The plates show the test rig: a tall testing machine with a vertical specimen clamped between platens, dial gauges, and cables, photographed in plain black and white with figure captions below. A designer might take from them the stark, symmetrical look of industrial load-testing equipment and the clean vertical lines of an H-beam profile.
