scholarly journals Finite fracture mechanics and cohesive crack model: Weight functions vs. cohesive laws

2019 ◽  
Vol 156-157 ◽  
pp. 126-136 ◽  
Author(s):  
P. Cornetti ◽  
M. Muñoz-Reja ◽  
A. Sapora ◽  
A. Carpinteri
Keyword(s):  
Fracture Mechanics ◽  
Cohesive Crack ◽  
Weight Functions ◽  
Crack Model ◽  
Cohesive Crack Model ◽  
Finite Fracture Mechanics ◽  
Cohesive Laws ◽  
Model Weight

Wedge-Splitting Test – Determination of Minimal Starting Notch Length for Various Cement Based Composites Part I: Cohesive Crack Modelling

2010 ◽  
Vol 452-453 ◽  
pp. 77-80 ◽  
Author(s):  
Václav Veselý ◽  
Ladislav Řoutil ◽  
Stanislav Seitl
Keyword(s):  
Fracture Mechanics ◽  
Cohesive Crack ◽  
Crack Model ◽  
Singular Stress ◽  
Initiation Point ◽  
Linear Elastic ◽  
Wedge Splitting Test ◽  
Splitting Test ◽  
Notch Length ◽  
Wedge Splitting

The geometric proportions of cube-shaped specimens subjected to wedge-splitting tests are numerically studied in the paper. The minimal notch length for specimens made of cement based composites varying in characteristic length of the material (a measure of material brittle-ness/heterogeneity) is verified using finite element method code with an implemented cohesive crack model (ATENA). The problem of assigning the crack initiation point (the notch tip vs. the groove corner in the load-imposing area of the specimen) is solved numerically also using both the theory of linear elastic fracture mechanics and the theory of the fracture mechanics of generalized singular stress concentrators in the second part of the two-part paper. Results ob-tained by the different approaches are compared. The minimal notch length is recommended.

scholarly journals A Particle-Based Cohesive Crack Model for Brittle Fracture Problems

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3573
Author(s):  
Hu Chen ◽  
Y. X. Zhang ◽  
Linpei Zhu ◽  
Fei Xiong ◽  
Jing Liu ◽  
...  
Keyword(s):  
Fracture Process ◽  
Cohesive Crack ◽  
Contact Model ◽  
Experimental Result ◽  
Crack Model ◽  
Mixed Mode Fracture ◽  
Cohesive Crack Model ◽  
Zone Method ◽  
The Impact ◽  
Linear Softening

Numerical simulations of the fracture process are challenging, and the discrete element (DE) method is an effective means to model fracture problems. The DE model comprises the DE connective model and DE contact model, where the former is used for the representation of isotropic solids before cracks initiate, while the latter is employed to represent particulate materials after cracks propagate. In this paper, a DE particle-based cohesive crack model is developed to model the mixed-mode fracture process of brittle materials, aiming to simulate the material transition from a solid phase to a particulate phase. Because of the particle characteristics of the DE connective model, the cohesive crack model is constructed at inter-particle bonds in the connective stage of the model at a microscale. A potential formulation is adopted by the cohesive zone method, and a linear softening relation is employed by the traction–separation law upon fracture initiation. This particle-based cohesive crack model bridges the microscopic gap between the connective model and the contact model and, thus, is suitable to describe the material separation process from solids to particulates. The proposed model is validated by a number of standard fracture tests, and numerical results are found to be in good agreement with the analytical solutions. A notched concrete beam subjected to an impact loading is modeled, and the impact force obtained from the numerical modeling agrees better with the experimental result than that obtained from the finite element method.

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