Mechanics of an Adhesive Anchor System Subjected to a Pullout Load. II: Viscoelastic Analysis

An analytical viscoelastic model is proposed to predict the time-dependent displacement of adhesive anchoring systems under axial tension. Using the correspondence principle, the elastic solution in Paper I has been extended to investigate the viscoelastic behavior of adhesive anchors. A model is developed to predict the creep behavior of adhesive anchoring systems, modeling the adhesive with a constant Poisson's ratio. Epoxy-based adhesives are modeled by a Prony series approximation, that is derived from experimental data of the creep compliance. The capability and the applications of the proposed model are demonstrated by analyzing and comparing the proposed model to existing experimental data. The closed-form approximate solution is then verified with a finite-element model (FEM) for various geometric and material properties. Since the proposed mechanics-based model is developed for a general case, it can be used in the design and the analysis of different types of adhesive anchoring systems, therefore capable of predicting their long-term performance due to creep.