Mechanical Behavior and Constitutive Modeling of Metal Cores

Studying the mechanical behavior of metal cores provides insight into the overall performance of structures comprising metal sandwich plates, and can help immensely in designing metal sandwich plates for specific engineering applications. In this study, the response of folded (corrugated) plate and pyramidal truss cores are explored under both quasistatic and dynamic loadings. In particular, two important characteristics of metal cores, the nonuniform hardening/softening evolution due to stressing in different directions and the rate-dependence, are discussed for different core topologies, including the square honeycomb core. In addition, the role of core behavior on the overall performance of sandwich plates is studied by employing a constitutive model for the elastic-plastic behavior of plastically compressible orthotropic materials [Xue et al. 2005]. The constitutive model is capable of capturing both the anisotropy of the core, associated with stressing in different directions, and its rate-dependence. The approach, based on employing the core constitutive model, not only significantly reduces the computation time, but also permits exploration of the role of each fundamental rate-dependent response of the metal core on the overall response of the metal sandwich plates.