Dynamic Model And Stress Analysis Of Brake Hub In CRH Running State

With the increasing speed of high-speed trains,stricter check and design demands of vehicle key parts are present.The brake hub(BH)is one of them and the connection between the brake disc and wheel shaft,which affects the stability.Many literatures reported that only mechanical theoretical analysis of braking is concerned on braking system safety to guide the brake disc hub strength check and design,but it can't reveal the early failure mechanism of the BH due to the neglect of mechanical theoretical of long-term running.BH working state includes:braking and running.Braking and running must be considered to reveal the mechanical behavior systematically.But mechanical analysis results have hardly been reported,can't guide design,running mechanics theory is an urgent problem.The mechanical behavior and experimental research of BH are raised to reveal early damage mechanism and predict fatigue life,to provide a theoretical basis for repair.The research works are as follows:(1)Research on dynamic analysis model of BH in running state and tooth stress calculation.Taking BH in running state as object,the load for establishing dynamic analytical model of BH is analyzed by elastic mechanics.Elastic small deformation coordinate equation is established by boundary conditions to solve BH tooth stress,and the dynamic tensile stress state of the teeth root is obtained in the running state.(2)Research on finite element simulation of BH in running state.The finite element model is established based on rotating circle and road spectrum inertia force.Taking trailer axle system as an example,the finite element simulation analysis is completed.The results are equal to analytics,and verify rationality of analytics.(3)Study on fatigue damage mechanism and service life of BH.Tooth stress spectrum is processed by rain flow counting method and inferred to obtain the 8-order stress spectrum,and the early fatigue damage mechanism and fatigue life are obtained by the P-S-N curve and residual strength model to provide method for design of BH.(4)Experimental study on fatigue damage mechanism of BH.Acoustic emission(AE)detection system is raised includes loading and test system.The loading method is designed by analytics and parameters are analyzed by PAC AE system.The results show signal is aroused for damage part when loading system creates dynamic stress calculated by analytics,and the analytics and damage mechanism are proved to be correct.