Wyniki wyszukiwania - Biblioteka Nauki

Ten serwis zostanie wyłączony 2025-02-11.

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Simulation of the Griffith's Crack Using Own Method of Predicting the Crack Propagation

100%

Podgórski J. , Gontarz J.

Advances in Science and Technology. Research Journal

2021

tom Vol. 15, no 4

1--13

The paper presents the results of numerical simulation of brittle material fracture initiated by Griffith's crack situated at any angle with respect to the load direction. The simulations were performed with the Simulia Abaqus FEA system using the X-FEM method. The direction of the crack propagation was determined using the user's subroutine written in Fortran, implemented in the Abaqus system. The authors programmed several conditions for the direction of the fracture propagation: maximum principal stress criterion, Ottosen-Podgórski criterion, three criteria based on displacements around the crack tip, and the MTS criterion, which is based on stress intensity factors. For the purposes of this study, two shapes of the crack tip were analyzed - sharp and blunted. The relationship between the direction of the initial fracture and the direction of crack propagation was found. The simulations were carried out for the angles of the initial crack from 0° to 90°, every 10°. A theoretical analysis of the implemented criteria was also carried out and compared to numerical results. The influence of the shape of the crack tip on the simulation result was analyzed. It was shown that the simulation results closest to the theoretical results were obtained for the own implementation of the stress-based criteria. It has also been proven that the shape of the crack tip has little effect on the result if the finite element mesh is properly densified. However, the sharp crack has a disadvantage for small initial crack angles. The Author’s method of predicting the crack propagation has been proven correct and effective. This work is also the basis for the further development of the described method.

Comparison between numerical analysis and actual results for a pull-out test

70%

Gontarz J. , Podgórski J. , Jonak J. , Kalita M. , Siegmund M.

tom Vol. 67, iss. 3

311--331

The paper describes a computer analysis of the pull-out test used to determine the force needed to pull out a fragment of rock and the shape of this broken fragment. The analyzed material is sandstone and porphyry. The analysis included a comparison of different methods of propagation of cracks in the Abaqus computer program using the Finite Element Method. The work also contains a description of laboratory tests and analytical considerations.