Torsional Strength of Multiple-Splined Shafts

BECAUSE of interest which has developed in a previous paper by the author on the same subject, and on account of questions raised as to the nature of the deformation of splined shafts when the deformation is carried beyond the elastic-limit, the previous tests which were carried only a little beyond the elastic-limit of the specimens have been repeated and extended to the rupture point. Additional specimens typical of those commonly used for permanent fittings were also tested for their own characteristics and for comparison with the form of test-specimens that were used in the series of tests that were previously described.

As in the previous tests, the results show that the torsional strength of the multiple-splined shaft is considerably less than that of a plain round shaft of diameter equal to the base diameter of the splined shaft. However, the elastic-limit of a shaft supported by a hub member, as in the case of a permanent fitting, is considerably higher than in a shaft not so supported. Dimensional details of the specimens are stated, stress-strain curves are presented and a brief discussion of the results is included.