The disc in the rotating metal-disc coupling produces alternating stresses when the angular misalignment is imposed on the coupling

which will result in fatigue problem.The stress analysis with the finite element method on the scalloped disc couplings is presented

which is the predominant type of flexible metal-disc couplings used throughout the industrial field.A transient dynamic analysis is carried out to simulate the rotating status when the coupling reacts to the various types of misalignment.Also a research about the impact that the rotating speed has on the diaphragm compound stresses

especially on the alternating stresses is developed.The result indicates that it provides a more effective method for the compound stress analysis of metal-disc coupling.