TY  - JOUR
AU  - Musraty, Walid
AU  - Međo, Bojan
AU  - Gubeljak, Nenad
AU  - Likeb, Andrej
AU  - Cvijović-Alagić, Ivana
AU  - Sedmak, Aleksandar S.
AU  - Rakin, Marko P.
PY  - 2017
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1532
AB  - Integrity of pipes is typically assessed by testing fracture mechanics specimens, such as compact tensile (CT) or single-edge notched bending (SENB). However, for some pipe dimensions it is not easy or possible to fabricate a specimen conforming to the requirements of standard procedures. A new type of specimen is proposed recently, which can be advantageous for relatively small pipe diameters and axial defects - the pipe ring notch bend specimen - PRNB. In this work, criteria for failure by ductile fracture of PRNB specimens are determined experimentally and by application of micromechanical analysis. The influence of size of the specimen, as well as size and shape of the stress concentrator, is analysed. The results of this study, along with previous authors results, lead to the conclusion that the pipe ring specimens can be applied in integrity assessment of pipes with defects. Also, the benefits of their application include much simpler fabrication and the same material history as the pipe itself. (C) 2017 Elsevier Ltd. All rights reserved.
T2  - Engineering Fracture Mechanics
T1  - Ductile fracture of pipe-ring notched bend specimens - Micromechanical analysis
VL  - 175
SP  - 247
EP  - 261
DO  - 10.1016/j.engfracmech.2017.01.022
ER  - 

@article{
author = "Musraty, Walid and Međo, Bojan and Gubeljak, Nenad and Likeb, Andrej and Cvijović-Alagić, Ivana and Sedmak, Aleksandar S. and Rakin, Marko P.",
year = "2017",
abstract = "Integrity of pipes is typically assessed by testing fracture mechanics specimens, such as compact tensile (CT) or single-edge notched bending (SENB). However, for some pipe dimensions it is not easy or possible to fabricate a specimen conforming to the requirements of standard procedures. A new type of specimen is proposed recently, which can be advantageous for relatively small pipe diameters and axial defects - the pipe ring notch bend specimen - PRNB. In this work, criteria for failure by ductile fracture of PRNB specimens are determined experimentally and by application of micromechanical analysis. The influence of size of the specimen, as well as size and shape of the stress concentrator, is analysed. The results of this study, along with previous authors results, lead to the conclusion that the pipe ring specimens can be applied in integrity assessment of pipes with defects. Also, the benefits of their application include much simpler fabrication and the same material history as the pipe itself. (C) 2017 Elsevier Ltd. All rights reserved.",
journal = "Engineering Fracture Mechanics",
title = "Ductile fracture of pipe-ring notched bend specimens - Micromechanical analysis",
volume = "175",
pages = "247-261",
doi = "10.1016/j.engfracmech.2017.01.022"
}

Musraty, W., Međo, B., Gubeljak, N., Likeb, A., Cvijović-Alagić, I., Sedmak, A. S.,& Rakin, M. P.. (2017). Ductile fracture of pipe-ring notched bend specimens - Micromechanical analysis. in Engineering Fracture Mechanics, 175, 247-261.
https://doi.org/10.1016/j.engfracmech.2017.01.022

Musraty W, Međo B, Gubeljak N, Likeb A, Cvijović-Alagić I, Sedmak AS, Rakin MP. Ductile fracture of pipe-ring notched bend specimens - Micromechanical analysis. in Engineering Fracture Mechanics. 2017;175:247-261.
doi:10.1016/j.engfracmech.2017.01.022 .

Musraty, Walid, Međo, Bojan, Gubeljak, Nenad, Likeb, Andrej, Cvijović-Alagić, Ivana, Sedmak, Aleksandar S., Rakin, Marko P., "Ductile fracture of pipe-ring notched bend specimens - Micromechanical analysis" in Engineering Fracture Mechanics, 175 (2017):247-261,
https://doi.org/10.1016/j.engfracmech.2017.01.022 . .

TY  - JOUR
AU  - Šoškić, Zlatan N.
AU  - Ciric-Kostic, Snezana
AU  - Galović, Slobodanka
PY  - 2016
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/1209
AB  - The paper presents a study of possibilities to extend the present methodology for thermal characterization of thin solid samples by photoacoustic techniques. The present methodology consists of linear fitting of the experimental data to approximate the expressions derived from the composite piston model of photoacoustic response and it is mainly used for calculation of thermal diffusivity of thin samples. The study has shown that the methodology may be extended to calculation of thermal diffusivity, thermal conductivity and thermal expansion coefficients of thin samples by linear fitting in multiple frequency ranges and by analysis of the intersection frequency, which is the frequency where the magnitudes of two components of photoacoustic response in the composite piston model are equal. The analysis of numeric errors of the methodology has revealed the dominant sources and magnitude of the errors, leading to the conclusion that photoacoustic techniques should be carefully used as a tool for extensive thermal characterization of thin samples in the cases when other techniques are not applicable or have larger errors. (C) 2016 Elsevier Masson SAS. All rights reserved.
T2  - International Journal of Thermal Sciences
T1  - An extension to the methodology for characterization of thermal properties of thin solid samples by photoacoustic techniques
VL  - 109
SP  - 217
EP  - 230
DO  - 10.1016/j.ijthermalsci.2016.06.005
ER  - 

@article{
author = "Šoškić, Zlatan N. and Ciric-Kostic, Snezana and Galović, Slobodanka",
year = "2016",
abstract = "The paper presents a study of possibilities to extend the present methodology for thermal characterization of thin solid samples by photoacoustic techniques. The present methodology consists of linear fitting of the experimental data to approximate the expressions derived from the composite piston model of photoacoustic response and it is mainly used for calculation of thermal diffusivity of thin samples. The study has shown that the methodology may be extended to calculation of thermal diffusivity, thermal conductivity and thermal expansion coefficients of thin samples by linear fitting in multiple frequency ranges and by analysis of the intersection frequency, which is the frequency where the magnitudes of two components of photoacoustic response in the composite piston model are equal. The analysis of numeric errors of the methodology has revealed the dominant sources and magnitude of the errors, leading to the conclusion that photoacoustic techniques should be carefully used as a tool for extensive thermal characterization of thin samples in the cases when other techniques are not applicable or have larger errors. (C) 2016 Elsevier Masson SAS. All rights reserved.",
journal = "International Journal of Thermal Sciences",
title = "An extension to the methodology for characterization of thermal properties of thin solid samples by photoacoustic techniques",
volume = "109",
pages = "217-230",
doi = "10.1016/j.ijthermalsci.2016.06.005"
}

Šoškić, Z. N., Ciric-Kostic, S.,& Galović, S.. (2016). An extension to the methodology for characterization of thermal properties of thin solid samples by photoacoustic techniques. in International Journal of Thermal Sciences, 109, 217-230.
https://doi.org/10.1016/j.ijthermalsci.2016.06.005

Šoškić ZN, Ciric-Kostic S, Galović S. An extension to the methodology for characterization of thermal properties of thin solid samples by photoacoustic techniques. in International Journal of Thermal Sciences. 2016;109:217-230.
doi:10.1016/j.ijthermalsci.2016.06.005 .

Šoškić, Zlatan N., Ciric-Kostic, Snezana, Galović, Slobodanka, "An extension to the methodology for characterization of thermal properties of thin solid samples by photoacoustic techniques" in International Journal of Thermal Sciences, 109 (2016):217-230,
https://doi.org/10.1016/j.ijthermalsci.2016.06.005 . .

TY  - JOUR
AU  - Mirkov, Nikola S.
AU  - Rasuo, Bosko
AU  - Kenjeres, Sasa
PY  - 2015
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/268
AB  - This article presents a new and substantially improved finite volume procedure for simulation of incompressible flows on non-orthogonal grids. Cell-centered least-squares gradients are obtained in a robust and highly accurate way. A new discretization of the diffusive terms is employed, which is based on extension of the original cell-face gradient interpolation and is more suitable for complex grid distortions. A flexible flux-limited interpolation of dependent variables on distorted computational grids is introduced. An efficient preconditioner for Krylov method solution of linear systems is proposed, which substantially improves the solution of Poisson equation for pressure correction. The pressure-correction algorithm is adapted for efficient convergence on highly complex grids using a sequence of non-orthogonal corrector solutions and its effect on iteration convergence is analyzed. The non-orthogonalities treated by current procedure are more accustomed to numerical grids generated from a real complex terrain elevation data. The main focus is on the simulation of atmospheric micro-scale flows pertinent to wind energy application.
T2  - Journal of Computational Physics
T1  - On the improved finite volume procedure for simulation of turbulent flows over real complex terrains
VL  - 287
SP  - 18
EP  - 45
DO  - 10.1016/j.jcp.2015.02.001
ER  - 

@article{
author = "Mirkov, Nikola S. and Rasuo, Bosko and Kenjeres, Sasa",
year = "2015",
abstract = "This article presents a new and substantially improved finite volume procedure for simulation of incompressible flows on non-orthogonal grids. Cell-centered least-squares gradients are obtained in a robust and highly accurate way. A new discretization of the diffusive terms is employed, which is based on extension of the original cell-face gradient interpolation and is more suitable for complex grid distortions. A flexible flux-limited interpolation of dependent variables on distorted computational grids is introduced. An efficient preconditioner for Krylov method solution of linear systems is proposed, which substantially improves the solution of Poisson equation for pressure correction. The pressure-correction algorithm is adapted for efficient convergence on highly complex grids using a sequence of non-orthogonal corrector solutions and its effect on iteration convergence is analyzed. The non-orthogonalities treated by current procedure are more accustomed to numerical grids generated from a real complex terrain elevation data. The main focus is on the simulation of atmospheric micro-scale flows pertinent to wind energy application.",
journal = "Journal of Computational Physics",
title = "On the improved finite volume procedure for simulation of turbulent flows over real complex terrains",
volume = "287",
pages = "18-45",
doi = "10.1016/j.jcp.2015.02.001"
}

Mirkov, N. S., Rasuo, B.,& Kenjeres, S.. (2015). On the improved finite volume procedure for simulation of turbulent flows over real complex terrains. in Journal of Computational Physics, 287, 18-45.
https://doi.org/10.1016/j.jcp.2015.02.001

Mirkov NS, Rasuo B, Kenjeres S. On the improved finite volume procedure for simulation of turbulent flows over real complex terrains. in Journal of Computational Physics. 2015;287:18-45.
doi:10.1016/j.jcp.2015.02.001 .

Mirkov, Nikola S., Rasuo, Bosko, Kenjeres, Sasa, "On the improved finite volume procedure for simulation of turbulent flows over real complex terrains" in Journal of Computational Physics, 287 (2015):18-45,
https://doi.org/10.1016/j.jcp.2015.02.001 . .