Study Of Comprehensive Evaluation Method Of The Operation Safety In Vehicle-track System

As the opening of the Beijing-Tianjin inter-city passenger railway with a highest speed of 350krn/h, Chinese railway officially entered the era of high-speed passenger railway.The traditional wheel-rail system will be faced with new problems, especially high-speed leads to high dynamic vehicle response forces and these forces can cause safety problems or heavy track loading and track deterioration.These problems directly affects the quality, efficiency and safety of rail transport. In the new era of high-speed passenger railway, it is essential to evaluate the safety of the vehicle in a better way. As one of the priorities in the current rail transport research, ensuring the safety of train operation and enhancing the quality of running is worth of our attention.Under the premise of the coupling thought of vehicle and track,this paper firstly analyze the factors which threat the safety of train operation and the problems of the current track irregularity management methods and train derailment research. From the standpoint of the wheel-rail contact geometry, considering the direct influential factors of wheel-rail displacement changing, and finding out a indicator-wheel-rail relative vibration displacement which could characterize the state of wheel-rail contact geometry with dynamic characteristics,and establishing the evaluation index system of the security of vehicle-track system operation.Secondly,on the basis of setting up vehicle-track coupling system dynamics model,the track irregularities are regarded as the input of system.The dynamics response of vehicle and track are calculated in different condition. The variation law of dynamics response values such as wheel-rail relative vibration displacement,wheel-rail contact forces,derailment coefficient and rate of wheel load reduction is analyzed.The results show that there is a strong correlation between the wheel-rail relative vibration displacement and the vehicle dynamic response.The method for evaluating the safety of the vehicle-track system takes the wheel-rail relative vibration displacement into account is more reasonable than using pure geometrical information.