The Simulation Research Of Dynamic Performance For HM-2 Draft Gear Based On Impact Test

Heavy haul railway transportation is an important trend in the development of railway freight transportation.The key technical problem is the research on the performance of longitudinal dynamics,and the buffer is the key component that affects the longitudinal dynamics of heavy haul train transportation.Therefore,the research on the performance of the new buffer has become an urgent need for the development of heavy haul railway transportation.The buffer is mainly used to absorb and consume the longitudinal impact kinetic energy produced by the train under various conditions of heavy load transportation,reduce the impact force between trains,and play an effective role in protecting the safety of trains,cargo and personnel.With the continuous improvement of train cargo requirements,performance of the buffer is also put forward higher requirements.In order to adapt to the development of heavy load train,by analyzing the relationship between the structure and impedance characteristics of the buffer and studying the numerical description of the dynamic characteristics of the buffer to select the reasonable structural parameters of the buffer.It provides important theoretical data support for train to realize heavy haul railway transportation,and has great practical application value.This paper analyzes the research status of buffer technology at home and abroad,the problems encountered in the development process,and the general situation of numerical simulation research for buffers.The structure,working principle and impedance characteristics of HM-2 buffer in China are described in detail.Based on the bicycle impact test data of HM-2 buffer,the loading curve is fitted with MATLAB polynomial,and the changing trend of loading curve is analyzed.The first and third order derivatives of the fitting curve are used to find the characteristic points of the fitting curve.And the loading curve of the buffer is described in sections.The characteristic of impedance varying with compression is described by cubic spline interpolation of feature points.Assuming that the compression speed of the buffer decreases linearly,the relationship between the impedance force and the velocity is obtained.The gridding model of buffer is constructed by using the relation of impedance with compression speed and compression quantity.Taking the test process of real vehicle impact test as an example,the numerical simulation program of bicycle collision is compiled with JavaScript language,and the buffer numerical gridding model is integrated into the single cycle crash program to simulate the impedance characteristics of the buffer during vehicle impact.By comparing the simulation results with the data of the bicycle collision test,the relative error of the maximum impedance force and the maximum compression of the buffer is less than 5%,which shows that the gridding model of the buffer can simulate the impedance characteristics of the buffer more accurately.It provides a good technical support for the design,research and application of buffer in the future.