Research On Lightweight Of Bus Body Skeleton Considering Dynamic Peak Force

Reducing the mass of buses can increase the bus driving range and reduce the number of replacement of battery power, and improve power, reduce the battery cost which has very important significance. Lightweight bus body skeleton study has very important significance, because the bus body frame is main carrying member. Currently the method of the body frame lightweight design is applying the static load. This method requires a dynamic factor. However, the dynamic factor needs a longer period to study.Taking one company hybrid buses body frame for the study example, mainly for the following tasks. Firstly, the three-dimensional model of bus body skeleton is established by SolidWorks, and imported ANSYS to make the typical working conditions of static analysis. Finally, the most dangerous working conditions that the body frame of the rear left wheel dangling conditions is got.Secondly, the vehicle buses virtual prototype model is established by the software ADAMS / Car, and the C-level road surface model is established by MATLAB based on harmonic superposition method.The each part load of the dynamic forces changing over time is got through vehicle virtual prototype simulation. The dynamic peak force of every key connection point is extracted as the boundary conditions of finite element analysis. Finally, the finite element model of the body frame based on dynamic peak force is established. Lastly, using Isight theoretical system software integrate the software CAD and CAE. The lightweight research of the bus body skeleton is studied. In order to reduce the total mass of the bus frame, the bus frame is optimized in the premise of ensuring the strength and rigidity. The design variables are the thickness of the longitudinal and cross-sectional beam while the objective is the total mass of the bus frame.Eventually, the total mass of the bus body frame is reduced by 8.84%. The bus frame lightweight effect is obvious. The bus frame is analyzed again to check whether the strength and rigidity meet the requirements. Reverse condition bus skeleton maximum stress is 283 MPa and the safety factor is 1.22.Full load condition bus skeleton maximum stress is 115 MPa and the safety factor is 3. The results show that the optimized bus frame can meet the requirements. The modal analysis of the bus frame is analyzed. The range frequencies of body frame the top ten natural frequencies were 6 ~ 15 Hz, stagger the incentive component of a larger excitation frequency which cannot cause resonance body structure.The designate of the bus body frame can be considered desirable.The result show that the method of the body frame lightweight design based on dynamic peak force is rationality and feasibility.The method of the body frame analysis based on dynamic peak force is equal with the method of the body frame analysis considering the dynamic load coefficient. The first method can accurately calculate the dynamic load factor loads of different locations, avoid experimental research questions under different conditions of dynamic load factor, shorten design time and save costs.