Structure Analysis And Optimization Of Marine Corrugated Diaphragm Coupling

The coupling is mainly used to connect the input and output shaft for torque transmission,Diaphragm coupling not only can be used to transmit torque but also through the metal elastic deformation of the original diaphragm to compensate for installation errors between the connecting shafts.In the course of work,the elastomer diaphragm has many kinds of failure forms like overload,fracture,and fatigue failure.As a new kind of diaphragm coupling,corrugated diaphragm coupling maintain all the features of the metal diaphragm coupling,and has some other features,such as being able to compensate for large axial displacements and having a linear axial stiffness,is a new development in the history of diaphragm coupling.However,due to the disadvantages of complex and expensive process,it is rarely used except in some special areas and the studies on it are relatively few.In this paper,the structural strength,fatigue life and vibration characteristics of a ship corrugated diaphragm coupling were researched.This paper mainly carried out the following aspects of research work:First of all,in this paper the finite element parametric model of the diaphragm was established.On the basis of determining the common load forms and the boundary conditions,the strength and stiffness of the diaphragm under different operating conditions was research by the nonlinear finite element method.Besides the effect of different diaphragm parameters on the stress distribution of the profile was investigated.According to the simulation results,the fatigue life of the diaphragm in the dangerous position was estimated by the nominal stress method.Secondly,the common vibration forms of diaphragm coupling were investigated,and the natural frequency was calculated theoretically.the finite element model of the whole coupling was established,and the natural frequency and mode shape of the coupling were analyzed when it was freely vibrating.Besides,According to the determined load form,the vibration modes of coupling which was pre-stressed are studied.Based on the analysis and calculation above,the critical speed of the coupling was estimated.Finally,based on profile safety factor concept,and the size of diaphragm with the goal of maximum safety factor and minimum volume was optimized by particle swarm optimization.After that,according to the previous simulation results,the diaphragm structure was improved,and a new curve formula of diaphragm profile was designed.Besides coMPared with the results before improvement,the advantages and disadvantages of the structure improvement model are discussed,which will provide reference for the selection and optimization design of the coupling.