Study On The Dynamic Performance Of Bogie Frame With The Effect Of Its Structure Parameters

As the core component of high-speed trains, the bogie is an important guarantee for the operation safety and forward to a higher speed. The frame, as the frame of bogie, is an important force bearing and transmitting component in the train. The structural form and parameters of the bogie frame not only affect the strength, stiffness and modal characteristics, and then affect the transient dynamic performance. At the same time, this kind of influence can be transmitted and coupled both through primary and secondary suspension, which will finally affect the dynamic performance of the vehicle. As a result, the structure design of the bogie frame will directly affect the running quality of high speed train. At present, the domestic high-speed trains are using H framework. It is a problem worthy of study that how to adjust the structure parameters of the bogie frame, so that it can not only meet the strength requirements, but also obtain a better dynamic performance under the new operating environment.In this paper, firstly, the structural parameters that affect the strength and dynamic performance of the frame are determined by means of literature research and mechanical analysis. And then the influence of structural parameters on the structural stiffness, natural vibration characteristics, transient dynamic performance and dynamic performance of the vehicle have been studied through the route of transmission along the mechanics effects of the frame. Finally, a qualitative and quantitative description of the influence of structural parameters and performance is established, which provides guidance for the structural design of the bogie frame.The change of frame structure parameters will cause to the change of structure stiffness at first. In general, the H typen frame is welded by the side beam, the beam and the end beam. It meets the requirements of calculation error when only considering the bending deformation and ignoring the shear deformation. So the bogie frame is abstracted into a plane steel frame structure in a reasonable simplification way. In this paper, the lateral bending stiffness of the frame is a case study, and according to the relevant standards by force method is derived from the principle of the relationship between the frame structure parameters and the lateral bending stiffness, which is verified the correctness of the model by simulation. Calculation results show that the wheelbase and beam spacing is the main structure parameters that effects lateral bending stiffness of the frame, both of which are cubic nonlinear relationship, this two parameters can be adjusted to effectively change the structure of transverse stiffness, while the lateral beam spacing have almost no influence on the lateral bending stiffness.Natural vibration characteristic is the intrinsic property of structure itself, and it is the important basis of structure design and performance evaluation. The change of structure will cause the change of natural vibration characteristics of the structure itself. The variation of the natural vibration characteristics under different structural parameters is the basis of the design of the structure. In this paper, the three parameters, wheelbase, beam spacing, lateral beam spacing, are used as input data, and the natural frequency and vibration mode of the frame are used as the output data. Constructing the finite element model of the framework by uniform design of input parameters, the influence of different structural parameters on the natural frequencies and modes of vibration in different parameters is obtained. Analysis results showed that:the change of structure parameters such as wheelbase of the frame have almost no influence on natural mode of vibration. The natural frequency is negatively related to the lateral beam spacing and wheelbase of the frame, and is positively related to beam spacing. That is, increasing lateral beam spacing and wheelbase of the frame will cause to reduce the natural frequency, and increase beam spacing of the frame will cause to increase the natural frequency of the frame, and vice versa.Because of the change of the structure parameters causing the change of the inherent properties of the frame, and then, the transient dynamic performance can be changed. At the same time, this kind of influence can be transmitted and coupled both through primary and secondary suspension, which will finally affect the dynamic performance of the vehicle. So in this paper, the different structure of frame influence on the dynamic characteristics are studied by means of analysis of transient dynamics and rigid flexible coupling dynamics simulation. Conclusions got in the thesis are as follows: â‘ It is favorable to the stability and the stability for a larger wheelbase of vehicle, but not the greater the wheelbase is, the better the vibration characteristics are. The vibration energy around 30 Hz will increase casuing by the larger wheelbase, and the first order natural frequency has a trend to shift to 30 Hz. So it is recommended that the wheelbase can take a larger value at same time avoid the frequency of elastic vibration.â‘¡It is not necessary to consider the influence of the elastic vibration because of the small influence of the natural vibration characteristics by changing the beam spacing and the lateral beam spacing in the design process. Although these two parameters have a certain degree of deterioration of the dynamic performance, but the impact is really small. So it can be more to consider the installation of components in the bogie frame that impact the size of the bogie frame chosen by.