Deformation Gradient-Based Remedy for Mesh Objective Three-Dimensional Interlocking Mechanism

Abstract

Interlocking over cracked surfaces is one of the primary sources of the shear force–resisting mechanism of general reinforced concrete structures. From the interlocking, shear stress develops in a substantially complex way due to the irregular asperity of cracked surfaces and the heterogeneous mixture of aggregate and cement. Previously, the author proposed a three-dimensional (3D) interlocking model that is rooted in microphysical interaction between a rigid particle and a soft matrix. However, the small deformation assumption and mesh sensitivity remain challenges. This study focuses on a novel computational method to achieve mesh objectivity of the 3D interlocking mechanism that can cover large deformations of general complex 3D RC structures. The proposed method exploits the deformation gradient at a separate domain where physical information of the crack-normal gap and crack-tangential sliding is rigorously defined. A generalized 3D version of the well-known crack band theory is infused into the interlocking mechanism, thereby giving rise to the mesh objectivity. This method can be directly applied to the large displacement and large rotation conditions.