Wing spar stress charts and wing truss proportions

Warner, Edward P
naca-report-214
1926


In order to simplify the calculation of beams continuous over three supports, a series of charts have been calculated giving the bending moments at all the critical points and the reactions at all supports for such members. Using these charts as a basis, calculations of equivalent bending moments, representing the total stresses acting in two bay-wing trusses of proportions varying over a wide range, have been determined, both with and without allowance for column effect. This leads finally to the determination of the best proportions for any particular truss or the best strut locations in any particular airplane. The ideal proportions are found to vary with the thickness of the wing section used, the aspect ratio, and the ratio of gap to chord.

An Adobe Acrobat (PDF) file of the entire report:
http://naca.central.cranfield.ac.uk/reports/1926/naca-report-214.pdf