Analysis Of Asphalt Pavement Response And Optimization Of Computational Efficiency

The mechanical response of asphalt pavement structure plays an important role in asphalt pavement design and performance evaluation.The linear viscoelastic(LVET)method can obtain the analytical solution of asphalt mechanical response in the frequency domain by applying the Elastic-Viscoelastic Correspondence Principle.However,the analysis process of viscoelastic analysis method needs a lot of computing time and computer storage resources.This study mainly illustrate the calculation method of mechanical response of asphalt pavement,and attempt to use Quasi-Elastic method to accelerate the calculation process of mechanical response of viscoelastic pavement.This study first reviews the elastic analysis methods commonly used in asphalt pavement mechanics and obtains the generalized elastic solution and the algorithm of pavement mechanics response under uniform load by displacement function method and global matrix respectively.Then the generalized solution of multilayer viscoelastic system and the algorithm of mechanical response in time domain are determined by the Elastic-Viscoelastic Correspondence Principle and Talbot's Numerical Inversion.Secondly,Schapery Quasi-Elastic method is used in this study to try to optimize the computational efficiency of asphalt pavement analysis.It is found that the Quasi-Elastic method is an approximation for the viscoelastic solution of asphalt pavement.Therefore,the method avoids the inverse Laplace transform,which takes up a lot of computation time,through the approximation principle,and can effectively reduce the computation time in the analysis process.Finally,in order to verify the accuracy and computational efficiency of the Quasi-Elastic method for analyzing the mechanical response of asphalt pavement,this study uses the linear viscoelastic solution as an evaluation index to verify and compare the quasi-elastic approximate solution.First of all,in order to ensure the objective and reasonable comparison results,the calculation program developed in the study needs to be verified.The elastic analysis program and viscoelastic program werer checked by BISAR and ABAQUS software respectively.The complex modulus test results are applied in order to determine viscoelastic characterization of asphalt layer,and the complex modulus and relaxation modulus of viscoelastic parameters of asphalt layer represented by MHN complex model are obtained,and the material parameters are brought into the linear viscoelastic theory method(LVET)and Quasi-Elastic method(QE)respectively to analyze the critical responses of typical pavements.After comparing the response results from GB/CTB base asphalt pavement under different temperatures and vehicle speeds,we draw the following conclusion: Quasi-Elastic method effectively improves the efficiency of mechanics response analysis of asphalt pavement,its time consuming is only 1/9 of the linear viscoelasticity methods,and in low temperature conditions can obtain more accurate response results.