The Research Of Parameters Mapping Relationship Between Modal Model And Physical Model Of Vehicle Body

When the Multiple Units runs at a high speed,the travelling comfort and safety must be up to the standard.Also the vehicle body must have a good static and dynamic characteristic.And the design of vehicle must be light.But for such large configuration like vehicle body,it is difficult to change the dynamic characteristics once it is constructed.And in the practical project,people often want to get the inside features of the vehicle body through the analysis of the observed data.Based on these two problems,this paper studies the mapping relationship between modal parameters and physical parameters of vehicle body and how to achieve the design from physical parameters to modal parameters.At first,this paper studies the parameters mapping theory of continuum vehicle body,just as the main vibration modals.Taking three free degrees of discrete system for example,this paper presents the discrete system parameters mapping relationship expressions.Also,the influence of the physical parameters on modal parameters is summed up when the system is in a particular situation.Secondly,this paper focuses on the model of minor structure of the vehicle body and tries to achieve the mass matrix and stiffness matrix of substructure model in various kinds of operating conditions based on the simulation software of ANSYS.According to the main vibration modals’ orthogonality and the least squares principle,this paper tries to extract the mapping relationship expressions between modal parameters and physical parameters and the correlation coefficient as well.Thus to realize the design from physical parameters to the modal parameters is available.We can calculate the variation of physical parameters with the order modal frequency changing.Taking each section of vehicle body as a unit,we will get the expressions of the mapping relationship between section’s modal parameters and physical parameters and summarize the influence of the section’s physical parameters on section’s modal parameters.Finally,this paper makes a conclusion of this study and proposes some suggestions for further research.