Fatigue Durability Analysis Of Light Trucks Based On Six-component Load Spectrum

From the practical point of view,fatigue is the process of failure under the action of alternating load,and the actual stress values are often lower than the yield strength of the material.The method of virtual fatigue analysis can be summarized as four aspects of fatigue analysis:material SN,EN curve,load spectrum,SN\EN fatigue analysis method and finite element calculation results.For the virtual fatigue analysis,load spectrum is the key factor in fatigue analysis,which directly reflects the damage degree of alternating load to vehicle under the condition of user(or test site).At present,most of the research focuses on how to use virtual fatigue analysis to comprehensively reflect the fatigue durability of users.In this paper,Dingyuan road pavement durability test field data acquisition of a light truck by WFT and data acquisition equipment.The specific work is as follows:1)Use the WFT and eDAQ acquisition equipment to conduct comprehensive pavement data collection for the road test field,analyze the collected data,and verify the data.The road test data was edited and applied to the 4poster to conduct an iterative analysis of the actual vehicle,and the iterative results were applied to the bench test of the relevant model;2)Build a MBS model of the vehicle,build a flexible frame and cargo box,the front and rear suspension,powertrain,build a rigid-flexible coupling model of the vehicle,and pass preliminary virtual iteration results and relevant time domain signals.Continuously adjust and optimize vehicle and system parameters;3)The influence of the parameters of the virtual iteration on the results of the virtual iteration is studied,and the process of the virtual iterative analysis is refined.Dividing the signals of different road surfaces in the road test field according to the road conditions of the test field,using the signal,the load spectrum of each system under different road conditions is iterated through a virtual iterative model;4)Establish the finite element model of the frame and the container,perform virtual fatigue analysis by modal superposition method(modal stress and modal coordinates).The analysis results are used to guide product design and optimization.