Random Vibration And Fatigue Strength Analysis Of Bus Skeleton For Army

A bus for army runs not only on concrete road but also on gravel road. It's important to process strength design of bus to fit with the safety and running condition. The static and dynamic analysis proceed with the finite element method, the vibration characteristic can be evaluated. We can also know the possible stress and distortion of the bus skeleton. After get stress distribution, it's necessary to process fatigue strength design.Based on the finite element dynamics,the research calculates the vibration modes of the bus skeleton including prestress. At last, calculate the stress response of it by inputting two types of road spectrum into the model; obtain the displacement, speed and acceleration responses of the maximum displacement points. Then, the research can get the resonance and coupling frequency which offer an important reference for the structure design. By using PSD analysis, According to Gauss three-interval method and Miner law, the fatigue strength of the bus skeleton is calculated. And the result meets the need of design on concrete road. But on the gravel road, the characteristic of anti-fatigue is feeble, so must improve the skeleton strength. The result after redesigned the structure shows that the bus body gets good fatigue strength.