Recent development in the computational micromechanics, thermal damage model and impact response of functionally graded materials

The recent progress in the mechanics of functionally graded materials in the State Key Laboratory in cooperation with the Japanese National Aerospace Laboratory is reported. Emphasis is put on the computational micromechanics, thermal damage model and impact response. The computational micromechanics combines a construction technique for a two-dimensional random geometry composed of multiphases with a finite element method. The main feature of the micromechanics is its ability to exactly construct the real random and graded microstructure of FGMs and its ability to exactly determine the relationship between the microstructure and properties. The thermal damage model deals with the damage problem of FGMs under cyclic thermal shock tests. A theoretical model is developed to examine an important thermal damage phenomenon: the coupling between the damage and heat conduction under cyclic thermal shock tests. The impact mechanics considers the dynamic response of a ceramic/metal FGM under high velocity impact. The propagation characteristics of impact waves across the interface between the ceramic and ceramic/metal interface are investigated. The effect of the composite properties and the ceramic thickness on the wave reflection across the interface is emphasized.