Domain analysis for airfield pavement: Moving forward from point responses

Current design methodologies for airfield pavement design are based on two failure mechanisms: bottom-up fatigue cracking and permanent deformation in the subgrade. Both mechanisms are based on strain at specific points in the pavement structure (tensile strain at the bottom of the Asphalt Concrete (AC) and vertical strain on top of the subgrade, respectively). However, point responses do not capture the multiaxial nature of stresses and strains. This paper uses a novel methodology called Domain Analysis that not only considers the three-dimensional (3-D) stress/strain state, but also relates regions in the pavement with typical distresses. In addition, various loading configurations are compared using a single scalar resulting from the Domain Analysis. The method uses outputs from finite element analysis and principal stresses/strains to isolate shear and mean states. The capabilities of Domain Analysis are demonstrated by analyzing a section built at the National Airport Pavement Test Facility subjected to a single gear loading of Airbus A-380, three temperatures, two tire-inflation pressures, and two tire speeds. Pavement response are calculated using an advanced finite element model that accounts for factors such as viscoelastic AC, 3-D nonuniform contact stresses and interaction between pavement layers.