The article deals with the impact of mass flow rate of abrasive in a water jet when penetrating into a material by using the vibration analysis. The vibrations of material were recorded by sensors placed on the experimental material.Values that were studied were amplitude and FFT (Fast FourierTransform) spectrum of
signal. The stainless steel AISI309 was used as the experimental material. Data recorded during the cutting process of theAWJ cutting were analysed by the
LabVIEWprogramming environment. The paper outlines the course of the recorded data and the FFTspectrum of this signal. Presented here is only a part of the
basic research focused on the application of vibrations as a feedback for on-line control of abrasive water jet.Članak se bavi utjecajem masenog protoka u vodenom mlazu, kada on prodire u materijal, koristeći analizu vibracija. Vibracije materijala zabilježene su
senzorima postavljenim na eksperimentalnom materijalu. Veličine koje su proučavane su amplituda i FFT
je nehrđajući čelik AISI 309. Podaci snimljeni tijekom procesa rezanja
sadrži djelomični rad temeljn
(brza Fourierova transformacija) spektar signala.
Kao eksperimentalni materijal korišten mlazom vode analizirani su LabVIEW
programskim okruženjem. Nadalje ovdje je opisan tok snimljenih podataka i FFT spektar ovog signala. Izvještaj og istraživanja
usmjerenog na primjenu vibracija kao povratne informacije za on-line kontrolu abrazivnog vodenog mlaza

Fusek, Martin

Harničárová, Marta

Hloch, Sergej

Hreha, Pavol

Konjatić, Pejo

Monka, Peter

Monková, Katarína

Valíček, Jan

Tehnicki vjesnik - Technical Gazette

The article deals with the impact of mass flow rate of abrasive in a water jet when penetrating into a material by using the vibration analysis. The vibrations of material were recorded by sensors placed on the experimental material. Values that were studied were amplitude and FFT (Fast Fourier Transform) spectrum of signal. The stainless steel AISI309 was used as the experimental material. Data recorded during the cutting process of the AWJ cutting were analysed by the LabVIEW programming environment. The paper outlines the course of the recorded data and the FFT spectrum of this signal. Presented here is only a part of the basic research focused on the application of vibrations as a feedback for on-line control of abrasive water jet.Članak se bavi utjecajem masenog protoka u vodenom mlazu, kada on prodire u materijal, koristeći analizu vibracija. Vibracije materijala zabilježene su senzorima postavljenim na eksperimentalnom materijalu. Veličine koje su proučavane su amplituda i FFT (brza Fourierova transformacija) spektar signala. Kao eksperimentalni materijal korišten je nehrđajući čelik AISI 309. Podaci snimljeni tijekom procesa rezanja mlazom vode analizirani su LabVIEW programskim okruženjem. Nadalje ovdje je opisan tok snimljenih podataka i FFT spektar ovog signala. Izvještaj sadrži djelomični rad temeljnog istraživanja usmjerenog na primjenu vibracija kao povratne informacije za on-line kontrolu abrazivnog vodenog mlaza

Pavol Hreha

Sergej Hloch

Jan Valíček

Katarína Monková

Peter Monka

Marta Harničárová

Martin Fusek

Pejo Konjatić

HRČAK - Portal of Croatian Scientific and Professional Journals

1Introduction2The issue being solvedUvodRješavani problem623, 4The development of new materials with specificfeatures requires the continual technologists' focus on theirpossibilities of machining. They encounter a need todevelop new technologies which are adequate formachining those new materials. The abrasive water jetcutting technology is one of these technologies. Theabrasive water jet is currently the most common cutting toolused in special application. It is able to provide cold cuttingof all known materials, so there is no thermal degradation ofmaterial that appears when using other non – conventionaltechnologies. The tool consists of a mixture of high-pressure water and abrasives that pass through a nozzle, so itis changed to a high velocity water jet with abrasivepermeate that is supplied to it [  ]. Despite the ongoinginvestigation of this technology, all the processes involvedin material cutting are not yet explainedThere are two ways of the abrasive water jet impact onmaterial. One of them is a smooth water jet penetration intothe material. Second one is the penetration caused by theshock impact of the water jet. This method is used to cut theclosed hollow products and also when punching, engravingand milling by the abrasive water jet. During penetrationthere is a back-flow of the hydro-abrasive mixture. Thepenetration through the material by the abrasive water jet isshown in Fig. 1. This issue has been studied in more detailsby Guo and Ramulu. They deal with the impact of abrasivewater jet onto the material by an optical method [  ]. Theirfurther research focuses on the water jet drilling [ ]. The475P. Hreha, S. Hloch, J. Valíček at al.ISSN 1330-3651UDC/UDK 534.13.08:621.7.044.4IMPACT OF ABRASIVE MASS FLOW RATE WHEN PENETRATING INTO A MATERIALON ITS VIBRATIONPavol Hreha, Sergej Hloch, Jan Valíček, Katarína Monková,Peter Monka, Marta Harničárová, Martin Fusek, Pejo KonjatićThe article deals with the impact of mass flow rate of abrasive in a water jet when penetrating into a material by using the vibration analysis. The vibrations ofmaterial were recorded by sensors placed on the experimental material. Values that were studied were amplitude and FFT (Fast Fourier Transform) spectrum ofsignal. The stainless steel AISI309 was used as the experimental material. Data recorded during the cutting process of the AWJ cutting were analysed by theLabVIEW programming environment. The paper outlines the course of the recorded data and the FFT spectrum of this signal. Presented here is only a part of thebasic research focused on the application of vibrations as a feedback for on-line control of abrasive water jet.Keywords: abrasive water jet, abrasive mass flow rate, penetration into material, vibration analysisPreliminary notesČlanak se bavi utjecajem masenog protoka u vodenom mlazu, kada on prodire u materijal, koristeći analizu vibracija. Vibracije materijala zabilježene susenzorima postavljenim na eksperimentalnom materijalu. Veličine koje su proučavane su amplituda i FFTje nehrđajući čelik AISI 309. Podaci snimljeni tijekom procesa rezanjasadrži djelomični rad temeljn(brza Fourierova transformacija) spektar signala.Kao eksperimentalni materijal korišten mlazom vode analizirani su LabVIEWprogramskim okruženjem. Nadalje ovdje je opisan tok snimljenih podataka i FFT spektar ovog signala. Izvještaj og istraživanjausmjerenog na primjenu vibracija kao povratne informacije za on-line kontrolu abrazivnog vodenog mlaza.Ključne riječi: abrazivni vodeni mlaz, abrazivni maseni protok, analiza vibracija, prodiranje u materijalPrethodno priopćenjeUtjecaj brzine abrazivnog masenog protoka na vibracije kod prodiranja u materijalUtjecaj brzine abrazivnog masenog protoka na vibracije kod prodiranja u materijalTechnical Gazette 17, (2010),4 475-480FigureSlika 1.1 Penetration caused by the shock impact of the waterjetProdiranje uzokovano udarcem mlaza vode[ ][ ]33research on the mechanism of penetration is currentlycarried out by Momber [  ], Guo [  ] Hloch [  ]. By theuse of acoustic emission and vibrations they are trying to getthe most detailed and accurate data about this not yetexplained removal phenomenon. Despite the great effort ofresearchers, there are still many unexplained phenomena inthis field of research. The vibrations have been ratherunderused when investigating this technology. Moreattention of researchers has been paid to acoustic emissionemitted by the process. Momber et al. [7] used acousticemission for online analysis of eroded materials. Foldyna etal. studied the high-pressure systems by using acousticemission [1]7 3 and 4. The authors of this article, Hloch and Valíčekdealt in previous works with the impact of factors onto theacoustic pressure level during the abrasive water jet cutting476Impact of abrasive mass flow rate when penetrating into a material on its vibrationTehni ki vjesnikč ,17, 4(2010)  475-4804Results and discussionRezultati i raspravaVibrations were examined during the penetration of thewater jet into stainless steel AISI 309. Two values of theabrasive mass flow rate = 250 g/min and = 400 g/minand also four values of the traverse speed of the cutting headwere examined as it is shown in Fig. 3. The technologicalconditions of the experiment are shown in Tab. 1. The timeinterval of the signals from the sensors was one second. Thecourses of vibration signals are shown in Fig. 5 and Fig. 6. InFig. 5 are shown the recorded signals during cutting with theabrasive mass flow rate = 250 g/min. In Fig. 6 are shownthe recorded signals during cutting of the samples with theabrasive mass flow rate = 400 g/min.As it can be seen, thesignals recorded by the mass flow rate = 400 g/min showm mvmmma aaaaP. Hreha, S. Hloch, J. Valíček at al.of materials and also elaborated a concept of surface qualityprediction for the abrasive water jet cutting process [8]. Forthe purpose of diagnostics of the technological process ofabrasive water jet cutting by vibration analysis [4] a series ofexperiments was performed.3Experimental conditionsEksperimentalni uvjetiThe material used for experiments was stainless steelAISI 309. The changes in the abrasive mass flow rate andalso the traverse speed of the cutting head were examined.The mass flow rate values were 250 and 400 g/min. Theselected traverse speeds of the cutting head were as follows:Table 1Tablica 1.Experimental conditionsEksperimentalni uvjetiFactors Experimental rangePressure p/MPa 350Traverse speed v/mm/min 50, 75, 100, 150Abrasive mass flow rate ma /g/min 250, 400Water orifice diameter do /mm 0,14Focusing tube diameter df /mm 0,8Standoff distance z/mm 3Number of passes 1Angle of attack φ, ° 90Type of abrasive Barton GarnetMESH 80Material thickness 15 mmType of materialAISI 309 – (Cr– Ni oceľ),chemical composition0,20 %, Mn 2%, Si 1 %,22 – 24 %, Ni 12 –15 %,0,045 %, S 0,03 %)mechanical properties(HRB 95, μ = 0,27 0,3,200 GPa, σ t = 515 MPa,σK = 205 MPa, = 40A %,50 %)–(CCrPE =Z =FigureSlika 2.2 Cutting of experimental samples of material AISI 309,E = 200 GPa; variable values: v = 50, 75, 100, 150 mm/min;m  = 250 and 400 g/min; constant values: p = 350 MPa,d  = 0,14 mm, d = 0,8 mm, z = 3 mm, = 90°Rezanje eksperimentalnih uzoraka od materiala AISI 309,E = 200 GPa; : v = 50, 75, 100, 150 mm/min;m  = 250 i 400 g/min; : p = 350 MPa,d  = 0,14 mm, d = 0,8 mm, z = 3 mm,promjenjive veličinekonstantne veličinea0 fa0 fφφ= 90°FigureSlika 3.3 Sets of experimental cuts produced under conditionsvariable values: v = 50, 75, 100 and 150 mm/min;m  = 250 and 400 g/min; constant values: p = 350 MPa, d  = 0,14 mm,d = 0,8 mm, z = 3 mm, = 90°; material AISI 309, E = 200 GPav = 50, 75, 100 i 150 mm/min;m  = 250 i 400 g/min; constant = 0,14 mm,d = 0,8 mm, z = 3 mm, = 90°; materijal AISI 309, E = 200 GPa–a 0fa 0fφφSeta eksperimentalnih rezova proizvedenih pod uvjetima –promjenjive veličine:veličine: p = 350 MPa, d50, 75, 100 and 150 mm/min. The technological conditionsunder which the experiments were carried out and therecords detected by the vibration sensor PCB IMI type 607are shown in Tab. 1. The shape of the experimental samplesand the position of the sensors are shown in Fig. 2.The vibration measurement was provided during AWJcutting of the experimental samples. Data collection wascarried by the NI PXI – 1031 measurement system, NI PXI –6109 for 8 – channel simultaneous collection with asampling frequency of 30 kHz. Vibrations were recorded byPCB IMI 607 A11 – uniaxial accelerometers. The recordeddata were consequently analysed by a tool that was createdin the object-oriented programming environmentLabVIEW 8.5./477Technical Gazette ,17, 4(2010)  475-480P. Hreha, S. Hloch, J. Valíček at al. Utjecaj brzine abrazivnog masenog protoka na vibracije kod prodiranja u materijalFigureSlika 4.4 Spectra of the recorded signals for cutting conditions variable values: v = 50, 75, 100 and 150 mm/min;m  = 250 and 400 g/min; constant values: p = 350 MPa, d  = 0,14 mm, d = 0,8 mm, z = 3 mm, = 90°; material AISI 309, E = 200 GPaSpektri snimljenih signala za uvijete rezanje – : v = 50, 75, 100 i 150 mm/min;m  = 250 i 400 g/min; : p = 350 MPa, d  = 0,14 mm, d = 0,8 mm, z = 3 mm, = 90°; materijal AISI 309, E = 200 GPa–promjenjive veličinekonstantne veličinea 0 fa 0 fφφof using the traverse speed of 150 mm/min. The frequenciesin the frequency range from 6 000 Hz up to 12 000 Hz showdecay in amplitudes. When using the abrasive mass flowrate of 250 g/min, the FFT spectra have got significantlydifferent distribution of the maximum amplitudes. Theseare moved to the top of the spectrum in the range from 0 upto 4 000 Hz.At the traverse speed of the cutting head = 100mm/min there has been observed the highest amplitude atthe frequency of 12 000 Hz.In this article the vibration signals recorded just duringthe penetration of the water jet were shown at different inputfactors such as the traverse speed of the cutting head and theabrasive mass flow rate.After the processing of the recordeddata, the authors came to the following conclusions:The increase in amplitude caused by the first contact ofthe tool with the material is observed at the beginning of thesignal. At the higher abrasive mass flow rate, the higheramplitudes were recorded, as it was expected. Higherv5ConclusionZaključak. ...a higher amplitude than the signals recorded during cuttingwith the mass flow rate = 250 g/min. An amplitude of thesignal recorded during cutting at the traverse speed = 150mm/min shows lower values by using the abrasive massflow rate = 400 g/min, unlike the other examined traversespeeds.All the signals contain a short section with increasedamplitude at the beginning of the signal. This section wascreated due to vibration of the material at the first contactwith the abrasive water jet. From this signal the FFT spectrawere obtained. These are shown in Fig. 4. The left sideshows the spectra obtained when using higher value of theabrasive mass flow rate. The right side shows the spectraobtained when using lower value of the abrasive mass flowrate. Both in the signal courses and in the FFT spectra, therehave been observed higher amplitudes by the abrasive massflow rate of 400 g/min, except in the case of using thetraverse speed of the cutting head = 150 mm/min.However, there are significant differences within thedistribution of maximum amplitudes. When using theabrasive mass flow rate of 400 g/min, there is an increase inthe amplitude at a frequency of 6 000 Hz. The maximumvalues are in a range of frequencies from 6 000 Hz up to12 000 Hz and at the end of FFT spectrum except in the casemvmvaa...478 Tehni ki vjesnikč ,17, 4(2010)  475-480Impact of abrasive mass flow rate when penetrating into a material on its vibration P. Hreha, S. Hloch, J. Valíček at al.6ReferencesLiteratura[1] Foldyna, J.; Sitek, L.; Habán, V.Acoustic wave propagation inhigh-pressure system. // Ultrasonics, 44, Supplement 1, 22December 2006, e1457-e1460.[2] Guo, Z.; Ramulu, M.; Jenkins, M. G. Analysis of the watercontact/impact on target material. // Optics and Lasers InEngineering, 33, 2(2000), 121–139.[3] Guo, Z.; Ramulu, M. Investigation of Displacement Fields inan Abrasive Waterjet Drilling Process: Part 2. NumericalAnalysis. // Experimental Mechanics, 41, 4(2001), 388-402.[4] Guo, Z.; Ramulu, M. Investigation of Displacement Fields inan Abrasive Waterjet Drilling Process: Part 1. Experimentalmeasurements. // Experimental Mechanics, 41, 4(2001), 375-387.[ ] H5 loch, S.; Valíček, J.; Kušnerová, M. Dělení materiáluvodním paprskem (6): Analýza vibračných spektierzískaných pri hydroabrazívnom delení hliníka. // Svařování,dělení, spojování materiálů, 6 (10), 1(2009), 42-43.Figure 5Slika .Record of the signals recorded when using the abrasive mass flow rate of m  = 250 g/min, a) v = 50 mm/min, b) v = 75 mm/min,c) v = 100 mm/min, d) v = 150 mm/min, p = 350 MPa, d  = 0,14 mm, d = 0,8 mm, z = 3 mm, = 90°; material AISI 309, E = 200 GPaZapis signala snimljen kada se koristiti abrazivni maseni protok m  = 250 g/min, a) v = 50 mm/min, b) v = 75 mm/min,c) v = 100 mm/min, d) v = 150 mm/min, p = 350 MPa, d  = 0,14 mm, d = 0,8 mm, z = 3 mm, = 90°; materijal AISI 309, E = 200 GPaa0 fa0 fφ5φamplitudes in the FFT spectra were also recorded.The distribution of the maximum amplitudes within theFFT spectra was concentrated at the frequencies up to 5 000Hz, when using the lower value of the abrasive mass flowrate. When using the higher value of the abrasive mass flowrate, the maximum amplitudes were distributed in themiddle of the frequency spectrum. We can claim that thehigher value of the abrasive mass flow rate moves thedistribution of the maximum amplitudes into the middle ofthe frequency spectrum.This study penetration of the material is part of a largervibration analysis AWJ cutting process. The aim of thisanalysis is to optimize input factors. It is also necessary tocarry out detailed studies in relation to the vibrationsgenerated by surface roughness..479Technical Gazette ,17, 4(2010)  475-480P. Hreha, S. Hloch, J. Valíček at al. Utjecaj brzine abrazivnog masenog protoka na vibracije kod prodiranja u materijal[6] Hloch, S.; Valíček, J. Vplyv faktorov na78 Valíček, J.; Hloch, S. Using the acoustic sound pressure levelfor quality prediction of surfaces created by abrasive waterjet.// The International Journal of Advanced ManufacturingTechnology, 48, 1-4(2010), 193-203, DOI: 10.1007/s00170-009-2277-3topografiu povrchovvytvorených hydroabrazívnym delením. Prešov, 2008, 125 s.ISBN 978-80-553-0091-7[ ] Momber,A. W.; Mohan, R. S.; Kovacevic, R. On-line analysisof hydro-abrasive erosion of pre-cracked materials byacoustic emission. // Theoretical and Applied FractureMechanics, 31, 1(1999), 1-17(17).[ ]Figure 6Slika 6.Record of the signals recorded when using the abrasive mass flow rate of m  = 400 g/min, a) v = 50 mm/min, b) v = 75 mm/min,c) v = 100 mm/min, d) v = 150 mm/min, p = 350 MPa, d  = 0,14 mm, d = 0,8 mm, z = 3 mm, = 90°; material AISI 309, E = 200 GPaZapis signala snimljen kada se koristiti abrazivni maseni protok m  = 400 g/min, a) v = 50 mm/min, b) v = 75 mm/min,c) v = 100 mm/min, d) v = 150 mm/min, p = 350 MPa, d  = 0,14 mm, d = 0,8 mm, z = 3 mm, = 90°; materijal AISI 309, E = 200 GPaa0 fa0 fφφFaculty of Manufacturing Technologiesof Technical University of Košice with seat in PrešovBayerova 1, 080 01 PrešovSlovak RepublicFaculty of Manufacturing Technologiesof Technical University of Košice with seat in PrešovBayerova 1, 080 01 PrešovSlovak RepublicFaculty of Mechanical EngineeringVŠB - Technical University of Ostrava17 Listopadu, 708 33 Ostrava-PorubaCzech RepublicMechanical Enginnering Faculty in Slavonski BrodJ. J. Strossmayer University of OsijekHR-35000 Slavonski Brod, CroatiaTrg Ivane Brlić-Mažuranić 2Authors' addressesAdrese autoraPavol HrehaSergej HlochKatarína MonkováFaculty of Manufacturing Technologiesof Technical University of Košice with seat in PrešovBayerova 1, 080 01 PrešovSlovak RepublicFaculty of Manufacturing Technologiesof Technical University of Košice with seat in PrešovBayerova 1, 080 01 PrešovSlovak RepublicFaculty of Mining and GeologyVŠB - Technical University of Ostrava17 Listopadu, 708 33 Ostrava-PorubaCzech RepublicFaculty of Manufacturing Technologiesof Technical University of Košice with seat in PrešovBayerova 1, 080 01 PrešovSlovak RepublicJan ValíčekPeter MonkaMartin FusekMarta HarničárováPejo KonjatićImpact of abrasive mass flow rate when penetrating into a material on its vibration P. Hreha, S. Hloch, J. Valíček at al.480 Tehni ki vjesnikč ,17, 4(2010)  475-480

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Utjecaj brzine abrazivnog masenog protoka na vibracije kod prodiranja u materijal

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Utjecaj brzine abrazivnog masenog protoka na vibracije kod prodiranja u materijal

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