Study On Local Strain And Fatigue Life Estimation Based On Elastic-plastic Finite Element Method For Asphalt Pavement

Asphalt pavement is often used in the form of high-grade road, which plays its uniquedriving comfort advantage, due to the influence of common diseases cracks, stability andbearing capacity of the road structure will be gradually reduced, which in turn exacerbate thedestruction of the road, affecting the normal use of the road and shorten its life. The currentdomestic and international understanding of the mechanism of fatigue cracking of asphaltpavement is consistent, but which is not deep enough research system, so it is necessary tostudy fatigue cracking of asphalt pavement, understand and analyze the fatigue properties ofthe asphalt mixture and pavement structure by the force characteristics, asphalt pavementfatigue life prediction method.In this paper, on the basis of analysis of the research results at home and abroad, thefatigue life prediction method based on the local strain of the asphalt pavement. Indoorasphalt mixes direct tension test and cyclic tensile test to analyze the fatigue characteristics,combined with the finite element method to determine the tensile strain threshold limit value,using multi-level multi-specimen test methods to determine the mixture under different strainthan the fatigue life to analyze the impact of mean stress that integrates four different strainfatigue life than to establish contingency-fatigue equation.The elastic-plastic finite elementmethod, the establishment of two-dimensional Drucker-Prager elastoplastic constitutivemodel, temperature, axle load, the surface layer thickness and modulus, base thickness andmodulus, crack layer thickness and modulus and other factors on the rigid basethe seams ofasphalt concrete pavement strain were investigated and calculated load strain and temperaturestrain the seams of asphalt concrete pavement structure, Marquardt of general purpose globaloptimization method to fit the bottom of the asphalt surface load strain practical formula,surethe pavement role effective axle load. Based on fracture mechanics theory, combined with thestrain-the fatigue equation Miner linear fatigue cumulative damage theory proposed thecalculation method of the fatigue life of the asphalt pavement, and examples contrast verifythe reliability of the actual road.