Simulation Of Quasi-brittle Fracture Research Articles

Comparative Studies on Mixed Mode Cohesive Interface Cracks of Quasi-Brittle Materials

Concerning on the modelling of quasi-brittle fracture process zone at interface crack of quasi-brittle materials and structures, typical constitutive models of mixed mode interface cracks were compared. Numerical calculations of the constitutive behaviours of selected models were carried out at local level. Aiming at the simulation of quasi-brittle fracture of concrete-like materials and structures, the emphases of the qualitative comparisons of selected cohesive models are focused on: (1) the fundamental mixed mode fracture behaviours of selected interface crack models; (2) dilatancy properties of the selected models under mixed mode fracture loading conditions.

Numerical Simulation of Quasi-Brittle Fracture in Concrete Structures with Extended Finite Element Method

In this paper, the extended finite element method (XFEM) is used for a discrete crack simulation of concrete using an adaptive crack growth algorithm. An interface model is proposed which includes normal and tangential displacements and allows the transfer of shear stresses through the interface. Different criteria for predicting the direction of the extension of a cohesive crack are conducted in the framework of the XFEM. On the basis of two examples, a comparison between the maximum circumferential stress criterion, the maximum energy release rate and the minimum potential energy criterion with experimental data has been carried out. The considered numerical simulations have confirmed the flexibility and effectiveness of the XFEM for the modelling of crack growth under general mode I and mixed-mode loading conditions.

Numerical Simulation of Quasi-Brittle Fracture in UHPFRC I-Beam as a Linear Complementarity Problem

This paper presents a numerical simulation of quasi-brittle fracture in UHPFRC I-beam as a linear complementarity problem. Based on the investigation of Tin-Loi and Attard, the simulation of quasi-brittle fracture in concrete has been extended to model UHPFRC I-beam by including a tensile hardening. Fracture is simulated through a hardening-softening fracture constitutive law in tension and a softening fracture constitutive law in shear at the boundary nodes, with the material within the triangular unit remaining linear elastic. LCP is used to formulate the path-dependent hardening-softening behavior in non-holonomic rate form. The good matching of test results and numerical results indicates the effectivity of this method.

A geometric nonlinear triangular finite element with an embedded discontinuity for the simulation of quasi-brittle fracture

This paper is aimed to model the appearance and evolution of discrete cracks in quasi-brittle materials using triangular finite elements with an embedded interface in a geometric nonlinear setting. The kinematics for the discontinuous displacement field is presented and the standard variational formulation with respect to the reference configuration is extended to a body with an internal discontinuity. Special attention is paid to the algorithmic treatment. The discontinuity is modeled by additional global degrees of freedom and the continuity of the displacements across the element boundaries is enforced. Finally, representative numerical examples for mode-I and mixed-mode fracture, namely a tension test, different three-point bending tests and a single edge notched beam with structured and unstructured finite element meshes are discussed to study the evolving crack pattern and to show the ability of the model.