Isogeometric cohesive zone modeling of interfaces in reinforced concrete structures

Abstract

AbstractIn reinforced concrete structures, the correct representation of the bond between concrete and reinforcement is a challenging task, since different mechanisms are acting simultaneously. On the other hand, the exact description of the reinforcement's geometry is not sufficient when using Lagrange shape functions and can additionally alter the modeling of this interaction. Isogeometric analysis enables the exact representation of complex geometries, and thus, can improve the correct description of the interface mechanisms. The concrete matrix and the reinforcement are modeled using boundary representation together with Non‐Uniform Rational B‐Spline (NURBS) and B‐splines Scaled Boundary Isogeometric Analysis (SBIGA) which is in accordance with the modeling technique in Computer Aided Design (CAD) tools. This allows for a straightforward use of the design model in the analysis process. The interaction mechanisms between reinforcement and concrete are modeled using a zero‐thickness interface in combination with a thermodynamically consistent cohesive zone model that captures the decohesion, compression and sliding effects. It includes a coupled damage‐plasticity dissipation for the normal and tangential direction. The model is verified using experimental results and a comparison to the standard finite element method (FEM) is carried out in order to investigate the benefits of applying isogeometric analysis for the exact representation of the reinforcement.