AXISYMMETRICAL THERMOMECHANICAL CONSTITUTIVE AND DAMAGE MODELING FOR AIRFIELD CONCRETE PAVEMENT UNDER TRANSIENT HIGH-TEMPERATURE

An axisymmetric thermomechanical damage model is proposed for airfield concrete pavement under very rapid heating and cooling processes due to high-temperature exhaust gas from vectored thrust engines. This is typical of advanced aircraft during their short vertical take-off and landing routines. The temperature and pore pressure distributions are investigated inside the airfield concrete pavement along the radial an d vertical directions. In addition, we derive the three-dimensional th ermoelastic stress-strain laws accounting for spherical void effects. Since the temperature range in this study is very large, thermal prope rties of concrete pavement are treated as functions of temperature. Th e spatial-temporal temperature field of the airfield concrete pavement is calculated numerically by the explicit finite difference method. S ubsequently, the pore pressure distribution is predicted based on the ASME Steam Tables and the foregoing temperature distribution. Within t he framework of linear thermoelasticity, the stress distributions are computed as functions of locations and time by the finite element meth od. Further, Newman's crack growth model is applied to estimate the de lamination (thermal spalling) time of the airfield concrete pavement a t various locations due to the internal pore pressure. (C) 1998 Elsevi er Science Ltd. All rights reserved.