Research On The Driving Safety Of High-Speed Trains Under The Influence Of Tornado Loads

As a rare natural disaster with extremely destructive power,tornadoes can cause huge damage to the surrounding infrastructure and building structures when they occur.As a beautiful business card of our country,high-speed railway not only plays the role of driving force for the country’s economic development,but also has the important meaning of maintaining social stability.Therefore,studying the impact of tornadoes on the driving safety of high-speed trains can not only provide a reference basis for high-speed railway route planning,but also provide a basis for decision-making on train operation and dispatch in the event of a tornado.In this thesis,the two-dimensional tornado wind field model proposed by Baker and the vehicle dynamic model with 27 degrees of freedom in vehicle system dynamics are used as the theoretical basis of tornado-vehicle coupling calculation,and a tornado-train coupling calculation program is written by using Python language.The vertical Wheel-Rail correspondence theory and The Simplified Kalker linear creep theory is adopted as the wheel-rail contact relationship model when compiling the tornado-train coupling calculation program.The Track irregularities is calculated by using the track spectrum of China’s high-speed railway and the trigonometric series superposition method.First,the distribution characteristics of the intensity,time,space,and duration of tornadoes that occurred in China’s mainland were analyzed based on the statistical data of tornado events in the China Meteorological Disaster Yearbook 2004-2018 for 15 years.Secondly,the influence of different tornado wind speed,vehicle driving speed,distance between tornado and route,and different route types on the safety of train is calculated and analyzed by using the tornado-train coupled power program written by the author.According to the calculation results,the reference limits for safe driving of vehicles under different working conditions are given.Finally,with the help of the Monte Carlo stochastic simulation algorithm and the tornado-train coupling dynamic model,the recurrence period of a tornado safety accident on a high-speed railway in Jiangsu Province was simulated and calculated.The calculation results show that based on the tornadoes in Jiangsu Province recorded in China Meteorological Disaster Yearbook for 15 years from2004 to 2018,and under the frequency of 30 pairs of trains a day,the high-speed railway route from Taicang,Jiangsu to Lianyungang,Jiangsu will encounter a safety accident caused by tornadoes every 108 years on average.