Reinforcing bars modelling using a rod–solid interface element without the need for mesh compatibility

Abstract

This paper presents a finite element methodology for modelling solid media with any number of straight or curved reinforcing bars (rebars). The formulation can handle rebars arbitrarily located within a 2D or 3D finite element mesh without the need for nodal compatibility. A new continuous rod–solid interface (or joint) element is developed to connect bulk elements to the rebars, including a method that directly considers the relative displacements. An arbitrary constitutive model can be used in conjunction with the proposed interface element to represent slip behaviour. In this regard, we also present a cyclic nonlinear constitutive model. Unlike existing embedded approaches, the proposed method allows for the direct application of boundary conditions at reinforcements’ endpoints, including tip bearing. The formulation is verified by comparing with literature examples and analytical solutions. In all cases, excellent agreement is observed. The approach can be conveniently applied to the study of complex reinforced concrete structures or any solid medium where reinforcing bars improve its mechanical properties.