محمود ملکوتی علون آبادی

Pavement is a part of a road and it is composed of several layers that is considered as the clearest part of a road for drivers. The most important damages stem from passing load on the flexible pavement is fatigue cracking. Fatigue age is depending on the horizontal strain on the bottom of asphalt layer. A situation of defect pavement is able to waste the money, increase fuel consuming and probability of accident. Thus, estimation of pavement response under applied loads is of importance. Evaluation of pavement response with an assumption of linear elastic behavior for all layers and under static loads is a simple work and can be easily analayzed by numericall approach. On the one hand, asphalt layer properties should be considered as viscoelastic because elastis modulus varies with the variation of temperature and time, on the other hand, applying of moving dynamic load, non-linear behavior of stone materials and the number of different layers of pavement withy different properties create a complicated situation for pavement analyse. Therefore, the behavior of a real pavement is complex and different. In this study, a 3-layer pavement under moving load with a linear viscoelastic behavior is simulated by Abaqus finite element software. In this model, the behavior of asphalt layer is considered as a linear viscoelastic and the influence of different parameters including moving load speed, asphalt concrete temperature and also influence of moving dynamic load on the pavement response is studied. Numerical findings confirm that increasing the temperature from 5 °C to 40 °C leads to an increase in the vertical deflection on the top of the asphalt layer, a decrease in the horizontal stresses on the bottom of asphalt layer and also an increase in the vertical stress on the top of the subgrade layer. Finally, on the constant temperature increasing the loading speed from 10 km/h to 120 km/h leads to a decrease in the pavement response.