ABSTRACT
This paper investigated perpetual pavement responses under single wheel and dual wheel aircraft gear loading using advanced Finite Element (FE) modeling. Four flexible pavement sections of construction cycle 7 (CC7) at the National Airport Pavement Testing Facility (NAPTF) were investigated. The FE model characterized Asphalt Concrete (AC) layer as viscoelastic material and calibrated in-situ material parameters using surface deflections under Heavy Weight Deflectometer (HWD). The time-dependent pavement responses under moving aircraft wheel loading were simulated. The tire loading was represented by the non-uniform contact stresses at the tire-pavement interface. Pavement responses such as tensile and shear strains in the asphalt layers under different wheel configurations and loading magnitudes were calculated and compared to the instrumentation measurements. As expected, both tensile and shear strains increase as the loading magnitude increases but decreases as the asphalt layer thickness increases. As compared to single wheel, dual wheel may cause the greater or smaller strain responses depending on the direction of tensile strain and the loading magnitude. In general, the effect of dual wheel loading becomes more significant as the asphalt layer thickness decreases. Future work will be dedicated to include four-wheel and six-wheel configurations in the analysis and consider wheel interaction effect for airfield pavement design.
