The FEM Model Researches On Diesel Equipment Of Locomotive With Integer Mounting Block

With the modification of structure and abundance of product category for diesel locomotive, some locomotives employ the diesel equipment structure mounted on the integer mounting block. Rare research has been carried out on vibration characteristics analysis for this kind of diesel generating set, which is necessary for the reliable operation of locomotive. Taking the diesel generating set of the N-type diesel locomotive as subject investigated, this paper researched a reasonable FEM modeling approach on the diesel generating set with integer mounting block, and analyzed the vibration characteristic of the structure and also put forward a improved scheme.The diesel equipment was simplified as the single mass system, and then the six natural frequencies and the corresponding vibration modes of diesel equipment were calculated. After processing the data from the different vibration testing ways on diesel equipment, the vibration displacement curves of 1.0 and 2.0 orders on measuring point in various working conditions were drawn. By analyzing the variation of the vibration amplitude of 1.0 and 2.0 orders on measuring point measured under four different working conditions, the three low order natural frequencies of the structural vibration for diesel equipment were determined. Utilizing these testing data, the amplitude and phase characteristics on measuring point were gotten, which had reference value for verifying the FEM model. The work above mentioned provided foundations for proving the rationality of the FEM model.Using the software ANSYS, the FEM model of the diesel equipment was built, and through modal analysis and calculation on the model established, the natural frequency and vibration mode of the diesel equipment were obtained. Comparing the results from the modal analysis and the calculations of the single mass system and the vibration mode characteristic of measured data respectively, it verified the rationality of the FEM model. And it concluded the model criterion of the FEM model through the model analysis on diesel equipment.In the end, it analyzed the major factors influencing structural vibration of diesel equipment using the FEM model and concluded that the diesel engine, the generating bracket, and the integer mounting block greatly affected the vibration modal characteristic of diesel equipment; and the material property of diesel equipment and the stiffness of vibration isolator had less impact. For diesel equipment of different structure, synthetizing each influencing factor, it brought about the improved scheme for the structure.The modeling approach and structure improved schemes presented in this paper can provide useful references for the design and modeling on the diesel generating set with integer mounting block.