Study of features of numerical simulation of falling weight tests on rigid pavements

Falling Weight Deflectometer (FWD) produces pavement responses upon an impact by a falling weight drop. The responses serve as inputs of backcalculation procedures to calculate the structural parameters for pavement evaluation. Many simulations were developed by imposing the impact force on pavement model neglecting the falling mass. This study investigated the effects of falling mass on FWD simulations, which were conducted with a finite element analysis package. Various falling heights, damping of rubber pads, and falling masses were considered to reveal the significance of these factors on pavement responses. The preliminary results show that falling mass may be ignored in FWD simulations as long as the time history of impact force is correctly recorded and used for general FWD simulations. The damping of underlying materials is significant in dynamic responses.