Anti-Fatigue Design On 70t New Type General Purpose Use Open Top Wagon Based On Virtual Model Machine Technology

With implementation of stride development strategy for China Railways, a series of heavy haul brand new products running at higher speed have been given birth to the market in railway industry. Since these new products put into service, the problem of fatigue breakage has become more prominent than before. Hence, for development of 70t new type general purpose use open top wagon, if the traditional static strength design philosophy were used for product design, it would inevitably result in much more static strength of the product structure available, but insufficient fatigue strength existing there, which would bring in the serious safety danger to the reliable service of the product. Therefore, it is of great significance in reality in carrying out anti-fatigue design on wagon body of 70t new type general purpose open top wagon based on virtual model machine technology.This paper presents the major research and study on 70t new type general purpose use open top wagon in the following aspects with careful study of key technical know-how of virtual model machine technology, that is to say, on the basis of performance simulation technology:At first, considering the structure feature and technical parameters of 70t new type general purpose use open top wagon, the detailed FEA model is established for the wagon body. Then the static strength analysis and modular analysis is done on the model in accordance with TB/T1335-1996"Strength Design and Test Accreditation Specification for Railway Rolling Stock". The position of the wagon body for the crack more easily occurring is finalized on the basis of the result of static strength analysis and welding types for the structure.Secondly, the anti-fatigue design on the welding seam on the key position of wagon body for 70t new type general purpose use open top wagon is performed based on the results of finite element static strength analysis, as per various load spectrums in AAR standard and due dynamic stress vs time, then characteristic curve of various welding joints as described in AAR standard and Miner damage theory.Finally, upon completion of prototype wagon production, the fatigue life forecast is carried out with the result of the static strength test and the load spectrum in AAR standard, also in contrast with the life forecast with the result of FEA, which illustrates that weak position is basically the same as each other. It shows that it is greatly significant and feasible for anti-fatigue design on the basis of virtual model machine technology.Anti-fatigue design on 70t new type general purpose use open top wagon as described in this paper attaches great importance for the reference to research and development of future new product. As there are various factors affecting fatigue life forecast and fatigue theory is not so mature as expected, therefore, it has become more difficult to forecast the fatigue life for the welding structure. The true value for fatigue life forecast embodies the comparison of different schemes at design stage for the optimum design scheme is finalized through comparison of fatigue life forecasts; meanwhile, the position for concern in the structure is figured out with the result of fatigue life forecast.