Dynamic simulation and safety evaluation of high-speed trains meeting in open air

Dynamic responses of a carriage under excitation with the German high-speed low-interference track spectrum together with the air pressure pulse generated as high-speed trains passing each other are investigated with a multi-body dynamics method.The variations of degrees of freedom（DOFs：horizontal movement,roll angle,and yaw angle）,the lateral wheel-rail force,the derailment coefficient and the rate of wheel load reduction with time when two carriages meet in open air are obtained and compared with the results of a single train travelling at specifie speeds.Results show that the rate of wheel load reduction increases with the increase of train speed and meets some safety standard at a certain speed,but exceeding the value of the rate of wheel load reduction does not necessarily mean derailment.The evaluation standard of the rate of wheel load reduction is somewhat conservative and may be loosened.The pressure pulse has significan effects on the train DOFs,and the evaluations of these safety indexes are strongly suggested in practice.The pressure pulse has a limited effect on the derailment coefficien and the lateral wheel-rail force,and,thus,their further evaluations may be not necessary.

Coal mine fire and human escape simulation

Coal mine fire and human escape simulation system is developed based on 3D Max and EON software for the purpose of coal mine safety training.The models,such as miners,roadways,typical equipments,fire and smoke are all constructed in 3D Max.The roadway models derived from real data,functions of each part are determined for the roadway based on the data,and then corresponding tunnel typical equipments are added.Emergency refuge system model is not only an important system model,but also an important destination for fire simulation and human escape.The roaming of the miners through the roadways,the interactive functions between users and computer,the fire process of beginning,spreading,and destroying,the human escape interaction are simulated in EON virtual reality software after these models have been input into it.Besides,collision detection based on hierarchical bounding volumes is also utilized.Simulation results suggest that this strategy can produce realistic virtual state and fire effect.While as part of the coal mine safety simulation and training System(CMSSTS),this work is far from what we expected,and there is more intensive work that should be done.

Safety modeling and simulation of multi-factor coupling heavy-equipment airdrop

Heavy-equipment airdrop is a highly risky procedure that has a complicated system due to the secluded and complex nature of factors＇ coupling. As a result, it is difficult to study the modeling and safety simulation of this system. The dynamic model of the heavy-equipment airdrop is based on the Lagrange analytical mechanics, which has all the degrees of freedom and can accurately pinpoint the real-time coordinates and attitude of the carrier with its cargo. Unfavorable conditions accounted in the factors＇ models, including aircraft malfunctions and adverse environments, are established from a man-machine-environment perspective. Subsequently, a virtual simulation system for the safety research of the multi-factor coupling heavy-equipment airdrop is developed through MATLAB/Simulink, C language and Flightgear software. To verify the veracity of the theory, the verification model is built based on dynamic software ADAMS. Finally, the emulation is put to the test with the input of realistic accident variables to ascertain its feasibility and validity of this method.

SIMULATION TESTS INITIATE PASSIVE SAFETY STUDY

Two simulation crash tests were carried out in Tianjin and Shanghai respectively with a domestically developed setup and a imported system. Both are for their first time in China. Through more than 3 year’s efforts and with the assistance of UNDP (United Nations Development Programme) Beijing, CATARC has established its simulation crash test setup for auto components. This setup is the first such kind of equipment developed in China, and it consists of catapult, energy absorption system, measurement system, high-speed camera, film analysis system, TNO-10 Dummy and HybridⅡ Dummy. The setup can be used to carry out