Analysis Of The Characteristic Characteristics Of Cracking Transmission Shaft Dynamics

In the process of shipbuilding,the normal operation of the transmission shaft is the key to ensuring the safe operation of the ship.When working on the transmission shaft,under the action of complex loads,cracks often occur in the axis component,causing abnormal work of the transmission shaft,and even a shaft fracture.If the axis crack cannot be found as soon as possible,the fault shaft can be dealt with,and it will seriously affect the smooth operation of the ship.Therefore,studying the dynamic characteristics containing crack transmission shafts,looking for the relationship between crack parameters and dynamic response,and realizing reverse recognition through dynamic response crack parameters,which is of great significance for the diagnosis of the transmission shaft crack failure.This article uses a crack-containing transmission shaft as the research object,using the finite element method to model the components of the transmission shaft,and consider the vertical-horizontal and reversing-horizontal coupling vibration of the shaft.The method of solving the coupling vibration,establishing an example model to analyze the coupling vibration,showing the existence of coupling vibration.Based on the theoretical basis of the fracture mechanics,it can start from the crack additional strain,and then use the energy method to obtain the crack additional rigidity matrix;for the simulation crack respiratory effect,the stress strength factor is zero method,and the additional rigidity matrix is obtained.Add cracks to the calculation model,calculate the response of the crack-containing model,and compare it with the ABAQUS simulation results to verify the correctness of the calculation result.In order to clarify the impact of the crack on the transmission shaft,by changing the crack parameters,the inherent frequency and rigid change curve diagram is obtained,and the effects of crack depth,inclination and front edge line shape on the transmission shaft are analyzed.Large;consider the differences between different crack models and breathing crack models,from the results of the response,the effects of frequent open crack models on the shaft coupling effect are more obvious;changing the speed of the transmission shaft,and found that the cracks mainly affect the shaft under low speed.When the axis speed is close to the critical speed,the cracking effect on the shaft response is very small;change the relationship between the crack and the response position,the relationship between the change of the crack position and the axis response,and find that when the response point and the crack span the bearings,the cracks have almost no response to the response.Impact;in order to further study the shaft coupling vibration,apply external incentives on the shaft,and through the axis response,the relationship between the response frequency and the incentive frequency is obtained.In order to realize the diagnosis of the crack fault of the transmission axis,the problem of crack parameter recognition is transformed into a target function to find the most valuable problem.By establishing a Kriging proxy model,the cracked transmission shaft base frequency value is predicted,and the accuracy of the model prediction is verified;here On the basis,establish a target function and optimize,use the NSGA-Ⅲ method to find the optimal group,complete the identification of crack parameters,and have a good identification effect.