The Experimental Research Of Vibration Characteristics And Operation Modal Based On CRH2G High-speed Train Car Body

China is a country with large population, and it’s a hot topic that large number of people has put pressure on transportation. Railway transportation which was supposed to be sunset industry return to the status of the main means of transport and lead China into the era of high-speed rail because of its large capacity, low cost, less energy consumption and light pollution after six times raise since 1997. With the development of economy, the progress of the society and people’s growing demand for material and culture, trains are required to be not only high speed but also stable and safe. It makes demands on train’s performance, especially the dynamic performance, under the Belt and Road major strategic form.Modal is structure’s natural vibration characteristics, which including natural frequency,damping ratio and model and so on. Those modal parameters can be obtained by calculation or test, the process to obtained modal parameters by calculation or test is modal analysis.Modal analysis is divided into calculating modal analysis and experimental modal analysis,and the calculating modal analysis refers to the process of modal parameters were obtained by the finite element calculation; experimental modal analysis refers to the process of modal parameters were obtained by test.Therefore, this paper will select CRH2 G train-set, with the speed of 250 km per hour and resistance to wind and cold, which independent designed by Sifang co., LTD, to study the vibration characteristics of high-speed train car body. The main content are as following:First, calculating modal analysis for CRH2 G car body based on the theory of finite element dynamic is built, and the large finite element software ANSYS are used to created three-dimensional finite element model form point to line and to surface.The vibration characteristics of car body is grasped through calculating and analysis, and then list previous order natural frequency and inherent vibration mode which have great influence to provide the basis for arrangement of measuring pointsSecond, by the experiment of car body line, it verifies that the car body first-order vertical bending vibration mode of the corresponding frequency match the standard requirement of not less than 10 hz.Third, by the comparison between results of simulation and test, the fact that the established vehicle simulation model is close to the actual structure is learned, and simulation model which not only save time, money, human resource and material resource but also reduce the security problem because of the test can be replace of test.Fourth, modal parameters which are the intrinsic characteristics of structure are not affected by operating mode and the external environment, but different operationalconditions have influences to the parameter recognition ability and recognition accuracy to different operational modal. So the impact of variables which refer to different speed,operating conditions, wind speed, operating sensors and location are discussed.