圆轴扭转无剪应力论证及试验研究

It is stated in the elastic theory that there exists a shear force on the longitudinal section and transverse section during the torsion of circular shaft, but actually the Torsional Point Moment of Force instead of shear force is ought to exist. It is first demonstrated in this study that the current elastic theory can not guarantee the balance of the partial body, and that the shear force from torsion of circular shaft is unable to support the plane assumption, therefore proving that there is no shear force on the longitudinal section and transverse section during the torsion of circular shaft. Secondly, the differential equation of comprehensive balance is used to prove that there is no shear force but a kind of Torsional Point Moment of Force in the body of pure torsion. At last, three types of columniform spiral springs are employed to conduct the compressive deformation test, and the compressive adisplacement as well as its corresponding load value F are measured. Finally, an average percentage error of spring is calculated by the stress theory with a result of 23.46% while by the Point Moment of Force theory is only 4.22%, which further verifies that torsional torque rather than shear force exists in the torsion of circular shaft. The study is a supplement and amendment to the current elastic theory of circular shaft torsional mechanics, and it plays an active role in solving the fracture problems of the non-slender shaft.