SEA-BASED FATIGUE LIFE ESTIMATION ALGORITHM AND PARAMETERS DESIGN FOR VEHICLE-PLATES EXCITED BY HIGH FREQUENCY FLUCTUATIONS

In order to study the fatigue life of high-speed vehicles excited by a turbulent boundary layer in a high-frequency band, frequency-domain fatigue damage estimation methods are discussed. A new method for the broad-band vibration fatigue life analysis based on statistical energy analysis(SEA) is approached. The principle of the method is to first calculate the mean square stress using SEA, and Poisson and Rayleigh distributions for resonance frequencies of the vehicle-plates are assumed to build the stress PSD curves of the dangerous point, then the fatigue life of the plate is analyzed using a Monte Carlo simulation. Verification shows that the method is accurate and feasible, and it is a reliable method for the strength design of high-speed vehicles. On this basis, the influence of structural damping and thickness on the fatigue life of the plate is discussed, the results show that a local optimal solution exists and structure weight can be reduced by using the local optimal solution as the design parameters of a vehicle-plate.