Research On Cracking Behavior Of Asphalt Pavement Based On Peridynamics

Reflective crack is one of the main forms of structural deterioration of semi-rigid base asphalt pavement.A correct understanding of the propagation mechanism of cracks in asphalt pavement is helpful to monitor the propagation behavior of cracks from the initial stage of crack development,so as to put forward targeted engineering protection measures and provide a reasonable technical scheme for the repair of cracks in asphalt pavement.Peridynamics(PD)theory is a non-local theory based on integral equation,in which the damage and fracture of materials are naturally reflected.PD theory effectively overcomes the inherent disadvantages of traditional numerical research methods in simulating crack propagation and has unique advantages in simulating damage and cracking of solid materials.Based on the PD theory,a numerical algorithm is proposed to analyze the damage and fracture behavior of asphalt concrete structures in view of the cracking and failure characteristics of asphalt pavement.A two-dimensional semi-rigid base asphalt pavement structure calculation and analysis model is established to systematically analyze the propagation behavior and influencing factors of reflective cracks in asphalt pavement.The main work contents are as follows:1.Based on the PD theory and the constitutive model of asphalt concrete,a numerical algorithm is proposed to analyze the damage and fracture behavior of asphalt concrete structures.The simulation results based on this algorithm agree well with analytical solutions and experimental results,which verifies the feasibility and correctness of the program.2.A numerical algorithm is proposed to analyze the damage and fracture behavior of asphalt concrete structures based on PD theory and the constitutive model of asphalt concrete.Then,a PD model of asphalt concrete slab is established,and the propagation path and failure mode of different types of cracks in asphalt concrete slab under different loads are studied.On this basis,the influence of initial cracks in different states on structural failure modes is analyzed by changing the length,Angle and number of initial cracks.3.According to the characteristics of semi-rigid asphalt pavement structure,a method of constructing multilayer structure model is proposed by modifying PD theory.Based on reasonable pavement structure parameters,the PD calculation and analysis model of semi-rigid asphalt pavement structure with cracks is established,the influence of different forms of load on the reflective crack propagation behavior of asphalt pavement structure was studied,and the inhibition effect of increasing the thickness of asphalt overlay on reflection crack was analyzed.4.According to the characteristics of interaction between vehicle and road structure,the effect of friction between wheels and road surface is taken into account.The reflective crack propagation behavior of road surface is analyzed under the conditions of vehicle loading approaching the crack and away from the crack,and the influence of friction direction between wheels and road surface on the reflective crack cracking behavior is discussed.