Fatigue Analysis Of Bus Skeletion And The Secondary Development

Bus body frame is the main bearing structure. Body frame strength, stiffness and fatigue properties have a direct impact on the life of the body frame, safety, handling and stability. The traditional design cycle is long and costs high. Therefore, in the body frame design’s area, analysis using finite element analysis and parametric secondary body development, can greatly shut down the body frame of the development cycle, and reduce development costs to improve design quality.With the research object of a certain type of bus body skeleton, this thesis elaborates the basic theory of finite element method (FEM), and investigates the building process of the body finite element model deeply. The three-dimensional data model is established by APDL language in ANSYS. And the bus drive size, materials, equipment, section and the quality of attachment parametric. By choosing unit types and defining the material properties, meshing grid, Applying loads, defining the boundary conditions, the finite element model of the body is made. To ensure sufficient passenger strength and stiffness, this sub-frame of four conditions on the bus were static analysis, and actual results and the relative ratio checked.Secondly, this theory based on fatigue damage, using ANSYS to calculate the body frame of the vibration mode, received the body’s natural frequency and corresponding vibration modes. Surface displacement spectra using random vibration analysis, calculated on a bus in the C-class driving road conditions in order to uniform random vibration stress and strain distribution of data and the maximum displacement point of displacement, velocity and acceleration response curve. Random vibration analysis using the stress results, according to Gauss law and Miner’s law three intervals were calculated fatigue strength. The results show that the body structure in the C-class roads meet fatigue requirements.Additionally, depending on structural features of the bus, I design on whole bus parametrically by the APDL language in ANSYS. I used the visualization software of VB to make the input interface simple. As VB interface shows the bus model parameterization and analysis process, non-professional staff can change parameters of the bus technically. These can make the analysis efficiency.