| Summary: | 碩士 === 義守大學 === 土木與生態工程學系碩士班 === 93 === The pavement structure and distress analyses will affect the pavement maintenance and design life. In the past, due to the complicated computation and time consuming of dynamic analysis, the pavement response under vehicle loading is often simplified to as static analysis. The purpose of this study is to develop the elasto-plasticity dynamic finite element program to model the pavement response under dynamic loading. In order to simulate the dynamic response of infinite half space, the finite element program is incorporated with the absorbing element to avoid wave reflection effect.
At first, the developed program is verified by one-dimension finite rod dynamic response analysis, and the results agree with the analytical solutions very well. It is also shown that the dynamic response of semi-infinite rod can be modeled with absorbing element in the finite rod. In the finite element domain study, the results show that the finite element analysis with absorbing element can reduce analysis domain and element number significantly. Secondly, the dynamic analysis of pavement is analyzed due to different types of loading. From the dynamic response of homogenous pavement, it shows that the vehicle speed does not affect the displacement result. However, the stresses response are increase by increasing the vehicle speed. In three-layer pavement structural dynamic analysis, the results show that the displacement response increase with the decrease of vehicle speed. However, the stress responses increase with the increase of vehicle speed.
It has been shown that the pavement materials exist the permanent deformation under repeated traffic loading. The modified elasto-plastic finite element program with Mohr-Coulomb and Drucker-Prager models are used to analyze the dynamic response of pavement. In the homogeneous pavement analysis, the displacement response with low speed is greater than that of high speed, and the stress response with high speed vehicle is greater than that of low speed vehicle. The displacement response from Mohr-Coulomb model is smaller than that of Drucker-Prager model. It is also shown that there exist residual stresses in the pavement after the loading is removed. The dynamic response of three-layer pavement is similar to that of homogenous pavement. The results also show that the displacement response from the Mohr-Coulomb model is greater than that of Drucker-Prager model. From this study, it is also shown that the stresses and displacements response are increased with the higher tire pressure.
|
|---|
