Ing. František Vlašic, Ph.D.
E-mail:   Frantisek.Vlasic@vutbr.cz  Pracoviště:   Ústav konstruování odbor technické diagnostiky Zařazení:   Ost. pedag. prac. Místnost:   A3/704

Vybrané publikace:

• SKŘIVÁNKOVÁ, V.; VLAŠIC, F.; VAVERKA, O.; MAZAL, P.:
  Influence of Surface Finishing to Fatigue Process in Additive Material
  článek ve sborníku mimo WoS a Scopus
  akce: NDT in Progress, Praha, 04.10.2021-06.10.2021
• MOHAMMAD, H.; MAZAL, P.; VLAŠIC, F.:
  Active Monitoring of RCF in Toroidal Bearings Using Acoustic Emission Technique, University of Oulu - Finnish Maintenance Society (Promaint).
  článek ve sborníku mimo WoS a Scopus
  akce: MCMD 2021: Fifth International Conference on Maintenance, Condition Monitoring and Diagnostics, Oulu, 16.02.2021-18.02.2021
• NOHÁL, L.; MAZAL, P.; VLAŠIC, F.; SVOBODOVÁ, M.:
  Acoustic Emission Response to Erosion-Corrosion and Creep Damage in Pipeline Systems, Elsevier
  článek v časopise ve Scopus, Jsc
• MAHMOUD, H.; MAZAL, P.; VLAŠIC, F.:
  Detecting Pneumatic Actuator leakage using acoustic emission monitoring
  článek v časopise ve Web of Science, Jimp
• MAHMOUD, H.; MAZAL, P.; VLAŠIC, F.:
  Relationship between acoustic emission signal and loads on pneumatic cylinders, Taylor & Francis Group
  článek v časopise ve Web of Science, Jimp
• KRATOCHVÍLOVÁ, V.; VLAŠIC, F.; MAZAL, P.; PALOUŠEK, D.; PANTĚLEJEV, L.:
  Analysis of fatigue processes of SLM materials by acoustic emission, Indescience Enterprises Ltd.
  článek v časopise ve Scopus, Jsc
• KRATOCHVÍLOVÁ, V.; VLAŠIC, F.; MAZAL, P.; PALOUŠEK, D.:
  Fatigue Behaviour Evaluation of Additively and Conventionally Produced Materials by Acoustic Emission Method,
  2nd International Conference on Structural Integrity, ICSI 2017, 4-7 September 2017, pp.393-400, (2017), Elsevier B.V.
  článek ve sborníku ve WoS nebo Scopus
  akce: 2nd International Conference on Structural Integrity, ICSI 2017, Funchal, 04.09.2017-07.09.2017
• MAHMOUD, H.; VLAŠIC, F.; MAZAL, P.; JÁNA, M.:
  Leakage Analysis of Pneumatic Cylinders Using Acoustic Emission, BINDT-Northampton NN1 5NX, UK
  článek v časopise ve Web of Science, Jimp
• MAZAL, P.; MAHMOUD, H.; VLAŠIC, F.:
  CONDITION MONITORING OF PNEUMATIC CYLINDERS BY ACOUSTIC EMISSION ,
  APPLICATION OF CONTEMPORARY NON-DESTRUCTIVE TESTING IN ENGINEERING, pp.231-238, ISBN 978-961-93537-3-8, (2017), University of Ljubljana
  článek ve sborníku ve WoS nebo Scopus
  akce: The 14th international conference of the slovenian society for non-destructive testing, Portorož, 04.09.2017-06.09.2017
• MAZAL, P.; VLAŠIC, F.; KOULA, V.:
  Use of acoustic emission method for identification of fatigue micro-cracks creation, Elsevier
  článek v časopise ve Web of Science, Jimp
• KOULA, V.; VLAŠIC, F.; DRÁB, M.; SLUNEČKO, T.; VOLÁK, J.:
  Utilization of Non-Destructive Methods for Monitoring Fatigue Crack Growth in Power Plant Material,
  XIth European Conference on NDT - Conference proceedings, pp.AEI-1-AEI-11, ISBN 978-80-214-5018-9, (2014), VUT v Brně
  článek ve sborníku ve WoS nebo Scopus
  akce: 11th European Conference on Non-Destructive Testing, Praha, 06.10.2014-10.10.2014
• MAZAL, P.; VLAŠIC, F.; BÁRTKOVÁ, D.:
  Application of Acoustic Emission for Identification of Differences in Fatigue Damage of Selected Materials for Power Plants, Trans Tech Publications
  článek v časopise ve Scopus, Jsc
• VLAŠIC, F.; NOHÁL, L.; MAZAL, P.; LIŠKUTÍN, P.:
  Study of High-Cycle Fatigue Behaviour of Titanium Alloy Using Acoustic Emission Method,
  Metal 2014 - 23rd International Conference on Metallurgy and Materials, pp.1423-1430, ISBN 978-80-87294-52-9, (2014), TANGER Ltd., Ostrava
  článek ve sborníku ve WoS nebo Scopus
  akce: METAL 2014: 23nd International Conference on Metallurgy and Materials, Brno, 21.05.2014-23.05.2014
• VLAŠIC, F.; VOLÁK, J.; NOHÁL, L.; MAZAL, P.; HORT, F.:
  Study of Initial Stages of Fatigue Process Using Non-destructive Testing Methods, Trans Tech Publications
  článek v časopise ve Web of Science, Jimp
  akce: Materials Structure & Micromechanics of Fracture (MSMF-7), Brno, 01.07.2013-03.07.2013
• MAZAL, P.; LIŠKUTÍN, P.; VLAŠIC, F.; HORT, F.:
  Usage of Acoustic Emission Signal and X-ray Diffraction Analysis for Detection of Microstructural Changes in Cyclically Loaded AlMg Alloys,
  Nondestructive Testing of Materials and Structures, pp.319-326, ISBN 978-94-007-0722-1, (2012), Springer
  kapitola v knize
  akce: Nondestructive Testing of Materials and Structures, Istanbul, 15.05.2011-18.05.2011

Seznam publikací na portálu VUT

Anotace nejvýznamnějších prací:

• NOHÁL, L.; MAZAL, P.; VLAŠIC, F.; SVOBODOVÁ, M.:
  Acoustic Emission Response to Erosion-Corrosion and Creep Damage in Pipeline Systems, Elsevier
  článek v časopise ve Scopus, Jsc
  Pipeline system failures confirm that special attention must be paid to the main components of nuclear power plants in particular. One of the significant degradation factors in terms of integrity and residual life of these components is erosion-corrosion in piping systems and creep in high pressure pipelines of thermal power plants. This article deals with analysis of a set of steel samples with different degrees of degradation using acoustic emission method based on detection of elastic-stress waves in a material. Time domain and frequency domain characteristics of acoustic emission signals generated by different creep mechanisms are analyzed. The main task is to find a relationship between crack creation and propagation and acoustic emission response. Part of the solution is also the design and implementation of a diagnostic method for operation monitoring of the deterioration of the high-pressure piping systems at high temperature. The benefit should be a significant reduction in the risk of damage to important components and reduction of the probability of damaging pipe wall integrity potentially sensitive to erosion-corrosion.
• MAHMOUD, H.; MAZAL, P.; VLAŠIC, F.:
  Detecting Pneumatic Actuator leakage using acoustic emission monitoring
  článek v časopise ve Web of Science, Jimp
  This paper focuses on the development of an efficient new diagnostic procedure for checking the function of pneumatic cylinders using acoustic emission. This diagnostic procedure is able to detect distinctive differences that determine whether the cylinder is damaged or undamaged. Moreover, the paper aims to find the diagnostic criteria that can be used to evaluate the pneumatic cylinder and detect defects. In this study, acoustic emission testing of several undamaged cylinders is carried out before artificial defects are created in each one. The signals from the progress and retreat strokes are recorded and analysed according to many parameters. The root mean square is normalised and the different responses of damaged and undamaged pneumatic cylinders are recognised by the time delay of the strokes. The differences are identified by comparing the maximum root mean square from sensor A and the maximum root mean square from sensor B for one cycle in the retreat stroke. The damaged and undamaged cylinders are distinguished using the difference in energy values present in the signals of the two sensors in the retreat stroke. The final evaluation of the cylinder is determined by calculating the total value of the root mean square. This paper is a continuation of a prior article and the extension of that work.
• MAHMOUD, H.; MAZAL, P.; VLAŠIC, F.:
  Relationship between acoustic emission signal and loads on pneumatic cylinders, Taylor & Francis Group
  článek v časopise ve Web of Science, Jimp
  This paper demonstrates the relationship between acoustic emission (AE) method parameters and loaded pneumatic cylinders. The cylinders in our experiment were loaded gradually by different weights in a vertical direction. The effect of the defect occurs when the cylinder is loaded at the retreat and progress strokes. This defect affects the relationship between the applied load and the recorded signal of the sensors. The signals of the acoustic emission were recorded from the progress and retreat strokes and then analysed. The time delay is calculated between the digital input and the initiation of movement, and the time of the stroke. The energy and root mean square of the acoustic emission compare between the distinctive different responses in damaged and undamaged pneumatic cylinders, with and without loading. The energy and RMS were calculated for each cylinder with gradual loading. The results of the test showed approximate linear relationship between the RMS and loading. This paper is a continuation of a previous article and the extension of my work to find distinctive differences that determine whether the cylinder is damaged or undamaged.
• MAHMOUD, H.; VLAŠIC, F.; MAZAL, P.; JÁNA, M.:
  Leakage Analysis of Pneumatic Cylinders Using Acoustic Emission, BINDT-Northampton NN1 5NX, UK
  článek v časopise ve Web of Science, Jimp
  This paper discusses the relationship between Acoustic Emission (AE) and different types of defects in pneumatic cylinders, shedding light on a new approach to determining these types of defects and distinguishing between them through Acoustic Emission. Difficulties that face the defects detection process are related to the types of the defects which occur, and the available methods for detection. A detection coefficient has been assigned to each cylinder by applying different methods of non-destructive testing, where a set of cylinders, which have defects that are difficult to detect, were determined. Two of those defects in the cylinders are artificially made, and it is difficult to discover the differences between undamaged and damaged cylinders in this set using current methods. Therefore, the necessary parameters for comparison have been selected after analysing the signals that were obtained from the tests. The average energy of Acoustic Emission signal RMS gives a clear picture of the different responses between damaged and undamaged pneumatic cylinders.
• MAZAL, P.; VLAŠIC, F.; KOULA, V.:
  Use of acoustic emission method for identification of fatigue micro-cracks creation, Elsevier
  článek v časopise ve Web of Science, Jimp
  Tento dokument je příspěvkem k diskusi o možnostech identifikace časového chování v různých stádiích únavového života přímo v průběhu zkoušení s použitím nedestruktivních metod testování (hlavně metody akustické emise). Zaměřujeme se zejména na detekci a charakterizaci přechodu z fáze akumulace cyklického poškození k tvorbě mikrotrhlin. V posledních letech, laboratoř únavových vlastností FSI publikovala řadu informací o kumulaci poškození převážně v Al a Ti slitinách. V tomto dokumentu jsou prezentovány a porovnány výsledky nových experimentů s ocelí používanou pro jaderné reaktory a slitinou niklu. Tato práce je zaměřena na srovnání vybraných parametrů signálu akustické emise v pre-iniciační a iniciační fázi tvorby únavových trhlin.