Car Body Design Parameters And The Study On The Relationship Between The Car Body Torsion Frequency

In recent years, in order to meet the rapid development of national economy, railway vehicles in China is moving toward high speed, high load, the direction of light car body, and its technology and performance advantages obtained the affirmation, the train operation safety and reliability are also put forward higher requirements. And car body design is an important part in the research of high-speed train, and car body stiffness is especially important in the design of car body. Car body stiffness is not reasonable, will directly affect the reliability of the locomotive car body, indicators such as security. Stiffness is divided into torsional stiffness and bending stiffness, this paper studied the torsional rigidity of the bodywork, and car body torsional stiffness of main evaluation parameters for torsional frequency.In this paper,the theoretical calculation formula of torsion frequency of vehicle body is derived. Firstly,the theory of torsional frequency of circular shaft is obtained by mechanical knowledge, and the frequency of the model is obtained by ANSYS, and the correctness of the formula is verified by comparing the results; Then establish solid rectangular cross-section beam model, used torsion of circular shaft frequency theory formula to calculate the torsional frequency of solid rectangular cross-section beam, and compared with the finite element results prove that theory of circular shaft calculation formula can be used for the calculation of solid rectangular cross-section beam, and the error is very small. And then establish the model of rectangular hollow thin-walled beam, reference spring calculation formula of vibration frequency, on the previous step formula is revised, get rectangular hollow thin-walled beam under torsion frequency calculation formula; then we derive the rectangular hollow thin-walled beam open pore model. Based on this, we give the body model of torsional frequency theoretical formulas for calculating, and introduce a correction factor, ultimately derive from the body torsional frequency calculation formula.In order to study the effect of various design parameters on the torsion frequency, in the paper made a sensitivity analysis of the various design parameters,we know that the body at the door of the influence of the stiffness is bigger. And establish the simplified finite element model in view of the influence of the change of the location and number of the train door torsion stiffness of car body steel structure, and also analyzes the influence o of car body torsional rigidity by the different door position and different number, and the influence of the door for torsional frequency are studied.The results prove that the car body first-order torsional frequency calculation formula is simple and effective,the position of the door the nearer to the end wall body,the smaller the first-order torsional frequency is.and near the middle reverse maximum frequency values, along with the increase in the number of the door, the first-order torsional frequency will decrease.