Analysis Of The High Speed Railway Carbody Dynamic Response Induced By The Aerodynamic Force And Irregular Excitation Of Track

Recent developments in railway engineering have been showing a trend to faster and lightweight vehicle design trains. The influence of air flow on the car body and the car is more and more significant. Different operating conditions, different speed levels, different running lines, the train will show a very complex flow characteristics and changes in the law.Train crossing condition, interaction pressure wave and vibration load under the coupling action of aerodynamic force and track irregularity, will enable the body vibration (especially transverse vibration) aggravated.In this paper, pneumatic and vibration behavior of the domestic high-speed train body of existing research goals, for different research, based on the theory of train aerodynamics and multi rigid body vehicle system dynamics, marshalling numerical simulation model is established. The effects of different operating conditions, running speed and track irregularity on the vibration of high speed train body are analyzed. The following conclusions are obtained through the study:(1) Establish the three high-speed trains in marshalling aerodynamics numerical model of open air and interaction operating conditions and model validation is performed using the measured data of projects. The changes of the pressure around body surface, train aerodynamic flow field and aerodynamic load shows that:the train during the crossing, when the train nose arrived at the measuring point measured pressure reaches a maximum, the entire crossing process, pressure region around the train is divided into:positive high voltage area-negative low pressure zone-Pressure smooth area-once a low pressure area-high-pressure zone; trains passing process, the side force and overturning moment most obvious change; with the increase speed of intersection, body surface pressure fluctuations more obvious, body pressure and gas power greater, but the distribution and changing trend of pressure and aerodynamic consistent.(2) The establishment of high-speed trains three marshalling multi-body dynamics model was applied to calculate the flow field and the aerodynamic loads of Beijing and Tianjin track irregularity spectrum calculation, conclusion:the crossing process, head car, middle car and tail car centroid transverse and vertical to the displacement fluctuation are relatively small, but the lateral displacement fluctuation was greater than that in vertical to the fluctuating displacement; centroid acceleration variation of homogeneous displacement; train derailment coefficient, wheel weight reduction load rate, axle lateral force and the wheel rail vertical force are with upgrading of the intersection speed increases, which leads to the reduction of train safety index. However, the maximum were less than the safety limit of limit values.(3) According to the analysis of transient dynamics theory, the aerodynamic loads and vibration acceleration loads was converted to stress and displacement response of apron dangerous point. Preparation of apron dangerous point in the open air intersection conditions under different load stress spectrum, and calculate the equivalent load and damage value. It is known that, after 12 million kilometers of running mileage, open air interaction condition of damage to 1.83E-05, it can be used to optimize the design of the structure, and the aerodynamic load standards to provide a reference for formulating.