# ESDU - Torsion and secondary warping constants for a bulb angle.

 Organization: ESDU Publication Date: 1 January 1983 Page Count: 4
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ESDU Struct 00.07.01 gives graphs for the torsion constant of a bulb angle section with legs of equal thicknesses, and for the secondary warping constant of a bulb angle section with legs of equal or unequal thicknesses. Each constant is plotted as a fraction of its value for a plain section with no corner radius. The torsion constant is a function of bulb radius, developed length of the median line of the section to the centre of the bulb, and the leg thickness. It is calculated taking the contribution of the corner radius to be that of a bar of radius equal to the thickness of the leg, which is adequate for radii between 1.2 and 1.8 times that thickness. The warping constant is a function of bulb radius, and of the thicknesses and lengths of the two legs. The effect of the corner radius is negligible. The formulae from which the curves were calculated are given. ESDU Struct 00.07.00 defines the torsion constant and the secondary warping constant.