Discrete Element Method (DEM) Contact Models Applied to Pavement Simulation Bo Peng Thesis submitted to the faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Master of Science In Civil Engineering Linbing Wang Montasir Abbas Cristian Druta June 18, 2014 Blacksburg, Virginia Keywords: Discrete element method, contact models, pavement simulation, power-low viscoelasticity