Two-dimensional meso-scale finite element models with real aggregates are developed using images obtained by digital image processing to simulate crack propagation processes in concrete under uniaxial compression loading. The model is regarded as a three-phase composite material composed of aggregate, mortar matrix and interface transition zone (ITZ). Cohesive elements traction–separation laws ...

APPROACH: Buckling driven delamination is difficult to control in experiments. Thus, the present study relies on numerical simulations using geometrically nonlinear finite element analysis as well as the softening foundation model, which is an adaptation of Winkler elastic foundation. Delamination fracture is modeled by a cohesive crack model. Dimensionless variables are used to cover the entir...

Abstract. In this work, an advanced numerical model, based on the cohesive zone approach and moving mesh technique, is proposed to simulate fracture propagation in quasi-brittle materials. particular, procedure consists of two stages. former one, according inter-element crack approach, once a suitable stress criterion for onset satisfied, boundary, representing segment, selected aligned along d...

This review paper discusses the basic problems related to use of cohesive models simulate initiation and development failure in various types engineering issues. The most commonly used zone (CZMs) are described. Recent achievements field modeling characterized, with particular emphasis on problem mixed mode loading, influence strain rate, stress state triaxiality, fatigue. A separate chapter wo...

The accuracy of an adopted cohesive zone model (CZM) can affect the simulated fracture response significantly. The CZM has been usually obtained using global experimental response, e.g., load versus either crack opening displacement or load-line displacement. Apparently, deduction of a local material property from a global response does not provide full confidence of the adopted model. The diff...

Background: This study aimed to assess the fracture resistance of zirconia restorations fabricated with rapid layer (RL group) technique and zirconia computer-aided design/computer-aided manufacturing (zir/CAD/CAM) system (ZC group). Methods:This study evaluated 30 all-ceramic crowns in two groups of 15. After fabricating the metal dies and scanning them ...

INTRODUCTION A fracture mechanics based approach has been recently proposed to measure the changes in fracture toughness of small animal bones due to aging, disease, and treatments for osteoporosis [1-3]. In contrast to standard strength tests, such tests require a smaller sample size [2] and provide a measure of material level changes [2,3]. Here we present a complementary computational approa...

Discretization induced oscillations in the load-displacement curve are a well known problem for simulations of cohesive crack growth with finite elements. The problem results from an insufficient resolution of the complex stress state within the cohesive zone ahead of the crack tip. This work demonstrates that the hp-version of the finite element method is ideally suited to resolve this complex...