مهندسی مکانیک شریف (Nov 2019)
FINITE ELEMENT MODELING OF TIRE MOVEMENT ON A SMART ASPHALT PAVEMENT AND INVESTIGATION OF DAMAGE RECOVERY (HEALING) EFFECT ON ITS LIFETIME
Abstract
The destruction of asphalt pavements is one of the biggest problems in road construction in the world, which incurs a huge amount of annual rebuilding. The healing process to recover damage is one of the effective methods to extend the life of these pavements, which has been presented by researchers in recent years. Self-healing polymers are a class of smart materials that, without the need for external stimulation, can repair part of the damage generated as microcracks and microvoids in their microstructures. Along with the purpose of the study, i.e., investigating the effect of healing in the lifetime of asphalt pavements, the explicit time-discrete form of the thermodynamically consistent model is presented in order to be utilized in a finite element ABAQUS software by VUMAT subroutine. The discretization method mentioned here has benefits such as low calculation costs and high reliability in response. Then, three-dimensional modeling of general vehicles' tire has been done using hyperelastic and viscoelastic materials in order to have the desired deformation on the pavement after applying the load. In the following, to evaluate permanent deformations (common failures in the asphalt pavement) and the effect of the healing process on its dilation, it is necessary to simulate its behavior in high-cycle loadings. In order to reduce the cost and time of computation, an alternative method has been used. In this method, in order to speed up the growth of damage and, also, healing effect, tire moving velocity has decreased. This may increase the time of loading on asphalt; therefore, rate of damage increase. In this simulations, the life of the asphalt pavement is compared with the effect of healing and without the effect. The results obtained from the simulations show that, by applying the effect of healing, the growth rate of damage and destructions caused by the permanent deformation of the pavement decreases, and the pavement lifetime can be increased up to more than 70\%.
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