Study On Prediction Of Antenna Hammock Seat’s Dynamic Stress Based On Modal Identification Of Bogie

ABSTRACT:In this paper, a new subway’s antenna beam is considered as the research object, identify modal parameters and dynamic loads of carcass and antenna beam’s Suspension seat. On this basis, establish a dynamic stress prediction model of the antenna beam’s Suspension seat.This paper introduces the basic principles of modal parameter identification method, compare the basic methods. And in Tianjin subway depot, according to the method of artificial excitation to identify modal parameter, using PolySLCF and PolyIIR modal parameter identification methods to get state modal parameters of the antenna beam install seat under the constraints. By the line test about the empty vehical on1line in Tianjin, getting the dynamic stress of the antenna beam install seat and vibration response of the bogie. In different conditions, combined with the characteristics of subway cars, chosing PolySLCF, NExT and SSI methods to identify the modal parameters of the bogie. Measure the function from excitation station to response station according to a single point excitation, establish the frequency response function matrix. Combined with vibration response measured in the line-test, identify the dynamic loads on the bogie. Combined with the results of modal parameter, analyze vibration transmission characteristics bogie.Based on the above results,establish a proper finite element model of bogie and the antenna beam install seat, exert dynamic load on the multi-body system dynamics analysis software LMS Virtual.Lab.Motion, calculate dynamic stress of the antenna beam install seat on different conditions.Use the measured Stress spectrum of antenna beam install seat spots to calculate equivalent stress amplitude, according to the fatigue strength maximal stress amplitude of the spots, make a fatigue assessment about antenna beam install seat, the result indicate that the strength accord with the requirement.The paper make a experimental basis for the followed study of the dymamics of the bogie,the identified modal parameters and dynamic loads canpredictive models be used to identify structural performance and structural modifications, can be used to predict the dynamic stress for antenna beam install seat.