Influence of the Harmonic Gear Drive Torsion Stiffness on Crack

The usage splits the fracture mechanics,the material mechanics and the system dynamics theories the influence of torsion stiffness of harmonic gear drive considering crack is researched. The analytic calculation formulas of flexibility and stiffness coefficient on each member considering crack are deduced.The solution calculation methods of torsion stiffness are given and a example is enumerated. This kind of method is simple,the in keeping with engineering calculation.