Reliability Analysis Of Bus Body Structure Based On Virtual Proving Ground

With the rapid development of China's economy,the automotive industry has developed rapidly,the number of bus also increased,and performance of the bus also made a very high demand.As the main bearing body,the strength,stiffness and fatigue performance of the bus body frame have a great impact on the safety performance of the bus.Therefore,how to design a more lightweight,more reliable body frame has become a major research topic in the field of bus.In the early stage of vehicle design and development,the automobile proving ground provides the design basis and technical support for the development of the automobile.The reliability test of automobile proving ground is usually used to verify and optimize the structural reliability of the vehicle.However,the production and modification of the sample vehicle often consumes a lot of manpower and material resources,and makes the vehicle design and design cycle longer.In order to shorten the cycle of product research and development,the United States ETA company has developed a vehicle simulation software—Virtual Proving Ground(VPG).We can use this software to build the vehicle's multi-body finite element model,and can call the real car test field road to the vehicle for reliability road test simulation,which provides another means for the evaluation of reliability verification of automobile.In this paper,we take the 6120 bus body frame as the research object.Firstly,the finite element model of the 6120 bus body frame is established by the Hypermesh,and then,we analyze the static working condition and mode of the frame.From the analysis results,the frame strength and frame stiffness meet the application requirements.Body frame before the 10-order natural frequency between 8.508 Hz ~ 21.412 Hz,can effectively avoid the resonance phenomenon,bus skeleton structure design is reasonable.The finite element model of vehicle body,suspension,tire and so on was established in the Virtual Proving Ground(VPG),Then,using the harmonic superposition method and Matlab software to calculate the C level random road surface vertical section curve,and establish the C level pavement finite element model.The dynamic stress time history of the body frame of the 6120 bus in C level pavement,cobblestone road,pave road,twist road and washboard road is obtained by simulation calculation of LS-DYNA.The Fatigue module in the Virtual Proving Ground(VPG)is used to analyze the fatigue life of the 6120 bus body frame in various typical reliability test road and verify the reliability of the 6120 bus body frame.This paper finds the five kinds of typical fatigue test under the condition of road,and puts forward the direction of improvement and strengthening for the following optimization design and manufacture.The use of Virtual Proving Ground(VPG)can provide a more accurate modification scheme for the optimization design of the vehicle,and provides a more efficient way to verify the reliability of the vehicle.