Lateral Elastic Instability Of Hat Section Stringers Under Compressive Load

A strain-energy method is presented for computing the compressive load for lateral elastic instability of hat-section stringers of simple cross section whose side walls and tops are flat and of constant thickness. Buckling stresses for such stringers having five different shapes and a range of lengths were computed by this method. The results confirm the opinion that lateral instability is an unlikely cause of failure for hat-section stringers.

This paper presents propeller characteristics for two propellers that differ only in inboard pitch distribution. The forward Mach number range extended to 0.062 and the blade-angle range was from 20 to 55 degrees. Section thrust-coefficient data are also presented to afford a more detailed analysis of the effects of modifying the pitch distribution of the inboard sections of a propeller.