Elastoplastic Damaging Model for Adhesive Anchor Systems. I: Theoretical Formulation and Numerical Implementation

In this and in the companion paper, the mechanical response of adhesive anchor systems is theoretically and numerically predicted and experimentally observed. The theoretical prediction is on the basis of an elastoplastic damaging model formulated to predict the structural response associated with the development of a fracture in adhesive anchor systems. This part describes the analytical model developed in the framework of a thermodynamically consistent theory, which assumes adhesion where the structure is sound, and friction in correspondence with the fracture. Isotropic damage is considered. The model can predict the structural behavior at the interface between two surfaces of ductile, brittle, or quasi-brittle materials. The Helmholtz free energy is written to model the materials' hardening or softening. Isotropic damage is considered, and the possible effects of dilatancy are taken into account, including nonassociative flow rules. The formulation is implemented into the finite-element code FEAP. In the companion paper, the new model is adopted to predict the mechanical response to the pullout force of postinstalled rebar chemically bonded in concrete. The analytical model and the numerical implementation are experimentally validated by several pullout tests, which are monitored by using an acoustic-emission technique.