A recurrence formula for shear-lag problems

Kuhn, Paul
naca-tn-739
December 1939


The analysis of the bending action in box beams with appreciable shear deformation of the flanges becomes very difficult in the general case of variable cross section and loading. This paper presents a convenient method of solving the problem by the familiar method of dividing the beam into a number of bays that can be assumed to have constant cross section and loading. Application of formerly derived shear-lag formulas leads to a general equation closely analogous in form to the well-known three-moment equation. A numerical example and two comparisons between calculation and experimental results are included.

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