The test Vehicle of higher speed is completed in CSR Qingdao Sifang Co., Ltd. short for “CSR Sifang”. Recently, experts engaged in the research work from CSR Sifang, Institute of Mechanics, Chinese Academy of Sciences, Beijing Jiaotong University, Southwest Jiaotong University, China Academy of Rail Sciences explain questions about purpose and meaning of developing test vehicle with a higher speed.
1. What’‘s the purpose and meaning for research and development of test vehicle of higher speed?
The development of test vehicle of higher speed is not for commercial operation, but exploring the critical value of the vehicle system in ceiling speed, implementing foresight, basic and theoretical research aimed at the security and reliability of the vehicle system, structure and material with the speed of 500 kilometers per hour. The main scientific objectives are:
Continue the in-depth research of the high speed vehicle security. Security is the decisive indicator for the technical development of high speed vehicle. Hope to increase the security redundancy through exploring the stability, structure strength, car-wire-net matching relationship of the high speed train in higher speed; carry out research of foresight and basic problems about high speed train in wider speed range, unveil the dynamics behavior, characteristics and laws about high speed trains, implement the research of response of coupling under higher speed, better directing the engineering practice and engineering application of commercial operating trains.
Provide test platform for basic scientific problems. The test train of higher speed will provide test basis for research of high speed train application basic theory, provide test vectors for “research of basic mechanical problems of high speed train under the speed of 500 kilometer per hour” of the State Plan for Development of Basic Research in Key Areas 973 plan, provide powerful guarantee for establishment of innovation environment of sustainable development.
Provide verification platform for application of new materials and new technologies. To further enrich and perfect high speed train technology system through application research and test of various new materials and new technologies, laying foundation for keeping sustainable development of our country’‘s high speed train technology, accelerating training of talent team and perfecting standards system.
2. What pre-technical foundation for development of higher speed test train China has had?
Chinese railway motor vehicle industry has accumulated some technology foundations in the fields of basic theory, research methods and technology standard through decades of development and exploration of high speed train technology. In 2004, the preliminary construction of the research platform of high speed motor train unit by introduction of mature technology of motor train unit of speed of 200-250 kilometers per hour, coupled with the existing technology and through joint design, line test and the applied assessment validation. In the subsequent process of research and development of high speed trains of various speed ratings, the theoretical model for research and development of high speed train has been gradually perfected through model analysis analytical demonstration, vehicle test verification, and theoretical mode cyclic iterative. Based on this, the higher speed train is developed through extrapolation technique. Implementation of test of higher speed rating will further perfect the theoretical model, providing solid theoretical support for research and development of subsequent motor train unit.
3. What’‘s the method of developing the test train of higher speed?
Based on CRH380A new generation of high speed train independent innovation achievements, with the chief objective of security and reliability under high speed, centering improvement of critical velocity, towing capacity, decrease of resistance, CSR Sifang implemented innovative research of system integration, head type, body, bogies, traction, and braking system, etc.
As for the safety in operation, the weight allowance of bogie design axis has an increase of about 10 percent, the critical unstable speed of test train exceeds over 20 percent in design speed; in the field of head form design, the test train adopts the pneumatic layout different from commercial operating trains, the head train adopts the “sword” shape with minimum resistance, the trailer adopts “rocket” shape with minimum aerodynamic lift, realizing the optimum matching of pneumatic performance and pneumatic safety under higher speed; in the aspect of network control, the real-time Ethernet technology is introduced, the 10-month system matching and reliability test is made through construction of special test platform, completing the development and verification of network control system of test train.
CSR Sifang is responsible for manufacturing of the test train, which is completed through two years, adopting the research model, integrating the domestic superior resources for scientific research, and implementing a series of rigorous scientific processes like simulation, numerical analysis, prototype development, testing and reliability testing ground. CSR ZELRI and CSR Motor are responsible for traction system and network control technology, CSR Puzhen is responsible for braking technology, and China Academy of Railway Sciences, Southwest Jiaotong University, Beijing Jiaotong University, Institute of Mechanics, Chinese Academy of Sciences, and Tongji University provide the technical support.
4. What kind of scientific experiments will be made on the test train?
The test train will mainly be used for the following four scientific research tests:
Research of high speed train key mechanics problems. In combination with the task content “research of basic mechanical problems of high speed train under the speed of 500 kilometers per hour” of the State Plan for Development of Basic Research in Key Areas 973 plan, carry out real line experimental study of Wheel-rail interaction , the gateway arch and fluid-solid coupling between the Department, acquire the change law of aerodynamic, structure, wheel track, pantograph upon the velocity, build the correlation between real train test data and bench and wind tunnel test data, correct the mechanical modeling, develop the basis for the mechanical properties of high-speed train analysis, and master the high speed train basic mechanics law in wider speed range, improving the basic research capacity of our country’s high speed train.
Research of critical system’s structural reliability. Providing data support for safe reliability in key structures like bogies, body, vehicle and equipment under the equipment cabin through test of vehicles under higher speed; carrying out the match between the bogies, body, car interior decoration and equipment under the vibration; studying the fatigue strength of key support parts; studying the influence rules of air under the action of different vibration excitation in the form of the influence of the vehicle structure through aerodynamic load test.
Verification of foresighted technologies like new materials and new technologies. Completing the test and verification work of new technologies including independent traction system, brake drag, real-time Ethernet through test items of Traction, braking performance, running resistance, and operation control; having a complete verification of various head type programs through research of various aerodynamic performance of aerodynamic drag, aerodynamic noise, aerodynamic lift, and the pressure wave intersection under open wire circuit and tunnel; analyzing and assessing the application prospect of new material through development and application of carbon fiber, magnesium alloy, nanometer insulation material.
Research of comprehensive comfort and noise. Implementing the research about the influence of moving test train on the passengers’ comfort in the aspects of vibration, noise, air pressure, temperature, humidity and illumination, to learn the pressure intensity inside and ourside the car and the changes of spectral characteristics with the noise increasing, explore the change law of train mode, vibration and noise and ride comfort under different conditions, providing important basis for the comfort design of motor train unit, and formulating the evaluation indicator and assessment approaches for China’s high speed train comfort through experimental investigations.
5. How about the development of test train and scientific test research in foreign countries?
The countries mastering high speed railway technology pay much attention to the development of high speed test train in the development process of high speed train technology, and then carry out scientific research and new technology demonstration. In 1988, the maximum test speed of ICE/V high speed test train developed by Germany reached 406.9 km/h. Since the operation of Japanese shinkansen in 1964, Japan had successively developed WIN350, STAR21, 300X, FASTECH360S, of which 300X developed in 1996 reached a maximum speed of 443 km/h. In 2007, the France-made V150 high speed test train created the world’s maximum test speed of 574.8 km/h. Based on high speed test train, these countries have carried out numerous research works about basic theory and application technology revolving around speed, safety and reliability index, and the research achievements obtained have effectively promoted the development of high speed test train technology and apparatus.
6. What new technologies and materials are adopted for the test train of higher speed?
The test train adopts numerous advance achievements in information technology, control technology and materials science. As for the application of new technology, the test train adopts the “drag brake” apparatus similar to the aircraft, which adopts Computer and network synchronization control and the auxiliary braking is applied through the addition of air resistance; the high voltage inverter high power IGBT is adopted in the traction system; in the aspect of information technology, the test train adopts real-time industrial Ethernet network control technology, digital broadcasting technologies and train-ground wireless transmission technology; and in the aspect of new material application, the test train adopts carbon fiber and magnesium and aluminum alloy in the car-body’s head cap and part of the interior apparatus, and the new nanometer insulation materials for improvement of the performance of sound absorption.