The Column Strength of Two Extruded Aluminum-Alloy H-Sections

Extruded aluminum-alloy members of various cross sections are used in aircraft as compression members either singly or as stiffeners for aluminum-alloy sheet. In order to design such members, it is necessary to know their column strength or, in the case of stiffeners, the value of the double modulus, which is best obtained for practical purposes from column tests. Column tests made on two extruded h-sections are described, and column formulas and formulas for the ratio of the double modulus to Young's modulus, based on the tests, are given.