Design and Analysis Procedures for Shafts and Splines

A general analytical and test procedure approach is presented for shafts under fatigue loading conditions. Construction and interpretation of comprehensive analytical curves are outlined, comprising the basic loading conditions of torsion alone, bending alone, combined bending and torsion, and cumulative damage. General spline design curves derived from fatigue tests are presented for torsional fatigue loading. The concept of nominal stress is used in correlating test and analytical curves, introducing simplicity and perspective in interpreting such complex factors on fatigue life as stress concentration, physical properties, and mode of loading.