Analysis of acoustic emission recorded during monitoring of abrasive waterjet cutting of stainless steel AISI 309

Tekst se bavi pratećim fizikalnim pojavama koje nastaju u procesu rezanja metalnih materijala tehnologijom abrazivnog vodenog mlaza (AWJ). Tekst opisuje uzroke nastalih vibracija i akustične emisije, tijekom vibracija i akustične emisije analizom njihova frekvencijskog spektra. Podaci su prikupljeni dodirnim senzorima u kontroliranom eksperimentu, u kojemu je korištena AWJ tehnologija za rezanje legiranog čelika. Tijekom eksperimenata, neki ulazni čimbenici su se mijenjali, a izmjereni parametri su bili podvrgnuti različitim vrstama analize pomoću specijaliziranog softvera LabVIEW. Dobiveni podaci pružaju informacije o vibracijama i spektru akustične emisije i omogućuju nam pronaći ovisnost između topografije površine rezanih materijala i spektra emisije popratnih fizikalnih pojava koje se javljaju tijekom AWJ procesa.The paper deals with the accompanying physical phenomena that arise in the process of cutting metal materials by abrasive water jet (AWJ) technology. The text describes the causes of arising vibration and acoustic emission, course of vibration and acoustic emission by analysing their frequency spectrum. Data were collected by touch sensors within controlled experiment, in which the AWJ technology for cutting alloy steel was used. During the experiments, some input factors were changed and measured parameters were subjected to different types of analysis using specialized software LabVIEW. Obtained data provide information about vibration and acoustic emission spectrum and enable us to find a dependency between the surface topography of cut materials and the emission spectrum of the accompanying physical phenomena arising during the AWJ process

Water jet technology used in medicine

Tehnologija abrazivnog vodenog mlaza od nedavno se koristi uglavnom u industrijskim područjima. Ova tehnologija pruža nekoliko prednosti u usporedbi s konvencionalnim metodama. Trenutačno, to je uporaba u medicini. U radu se razmatra mogućnost korištenja tehnologije mlaza vode u medicini. U radu su opisane prednosti i uporaba u ortopedskoj kirurgiji, plastičnoj kirurgiji, neurokirurgiji, dermatologiji, urologiji te u oralnoj kirurgiji.Abrasive water jet technology has been recently used mainly in industrial areas. This technology provides several advantages in comparison with conventional methods. At present, it is used in medicine. This paper discusses the possibility of using water jet technology in medicine. The paper describes the benefits and usage in orthopedic surgery, plastic surgery, neurosurgery, dermatology, urology, and in dental surgery

Influence of focusing tube wear on vibrations and surface roughness

Rad se bavi ispitivanjem utjecaja istrošenosti fokusirajuće cijev na kvalitetu površine i vibracije koje proizvodi abrazivni vodeni mlaz, putem eksperimenata. Pokusi se bave procjenom utjecaja istrošenosti fokusirajuće cijevi na kvalitetu površine i parametre vibracija nastalih rezanjem abrazivnim vodenim mlazom. Glavni zadatak prvog eksperimenta bio je proučiti značaj četiri odabrana faktora nezavisnih varijabli (istrošenost fokusirajuće cijevi, brzina prijelaza, protok abrazivne mase i tlak) potpunom faktorijalnom analizom na dvije razine. Cilj drugog eksperimenta bio je istražiti utjecaj istrošenosti fokusirajuće cijevi na parametre vibracija. Uočeno je da istrošenost fokusirajuće cijevi ima značajan negativan utjecaj na kvalitetu površine i parametre vibracije.The paper deals with the study of the focusing tube wear influence on surface quality and vibrations produced by abrasive waterjet by means of experiments design. The experiments deal with evaluation of the influence of focusing tube wear on surface quality and parameters of vibration generated by abrasive waterjet cutting. The main task of the first experiment was to study the significance of four selected factors of independent variables (focusing tube wear, traverse rate, abrasive mass flow rate and pressure) by full factorial analysis at two levels. The aim of the second experiment was to study the influence of focusing tube wear on the vibration parameters. It has been observed that focusing tube wear has a significant negative influence on surface quality and parameters of vibration

Water jet technology using at orthopaedic surgery

Rad se bavi mogućnošću uporabe tehnologije vodenog mlaza i njegovom preinakom za rezanje koštanog tkiva i bio-materijala. Sažima sadašnje stanje znanja, definira probleme s tehnološke i kirurške točke gledišta, kako bi se povećala kvaliteta liječenih klijenata. Članak predstavlja pregled i prvi korak ka uporabi tehnike vodenog mlaza u ortopediji, tijekom rastavljanja međuspoja između kosti i bedrenog stabla.The paper deals with potential uses of water jet technology and its modification for cutting of bone tissue and bio-materials. It summarises the present state of the art, defines problems from the technological and surgical point of view in order to increase the quality of treated clients. The paper represents an overview and the first step towards using water jet technique in orthopaedic surgery, during dissintegration of interface between bone and femoral stem

Rationalization of manufacturing of plastic injection moulds by abrasive waterjet

Rad se bavi prijedlogom i teorijskim rješenjem za racionalizaciju proizvodnje dijelova kalupa za ubrizgavanje plastike rezanjem abrazivnim vodenim mlazom. Na temelju eksperimentalnih ispitivanja i primjenom napredne tehnologije abrazivnog vodenog mlaza u procesu proizvodnje kalupa za ubrizgavanje plastike, utvrđeno je da postoji mogućnost prilične uštede vremena, odnosno značajno smanjenje vremena proteklog od narudžbe do isporuke proizvoda. Na taj je način moguće povećati konkurentnost tvrtke i osigurati joj stabilnu poziciju na tržištu, čak i u vrijeme globalne krize.The article deals with a proposal and a theoretical solution for the rationalization of manufacturing of parts of plastic injection moulds by abrasive waterjet cutting. On the basis of experimental tests and by the application of advanced abrasive waterjet technology to the process of manufacturing of plastic injection moulds, it has been found that there is a possibility of considerable time saving, i.e. a marked shortage in time period from product ordering to dispatching. In such a way it is possible to increase the competitiveness of a company and to ensure its stable position on the market even in the time of global crisis

Analysis of acoustic emission recorded during monitoring of abrasive waterjet cutting of stainless steel AISI 309

Tekst se bavi pratećim fizikalnim pojavama koje nastaju u procesu rezanja metalnih materijala tehnologijom abrazivnog vodenog mlaza (AWJ). Tekst opisuje uzroke nastalih vibracija i akustične emisije, tijekom vibracija i akustične emisije analizom njihova frekvencijskog spektra. Podaci su prikupljeni dodirnim senzorima u kontroliranom eksperimentu, u kojemu je korištena AWJ tehnologija za rezanje legiranog čelika. Tijekom eksperimenata, neki ulazni čimbenici su se mijenjali, a izmjereni parametri su bili podvrgnuti različitim vrstama analize pomoću specijaliziranog softvera LabVIEW. Dobiveni podaci pružaju informacije o vibracijama i spektru akustične emisije i omogućuju nam pronaći ovisnost između topografije površine rezanih materijala i spektra emisije popratnih fizikalnih pojava koje se javljaju tijekom AWJ procesa.The paper deals with the accompanying physical phenomena that arise in the process of cutting metal materials by abrasive water jet (AWJ) technology. The text describes the causes of arising vibration and acoustic emission, course of vibration and acoustic emission by analysing their frequency spectrum. Data were collected by touch sensors within controlled experiment, in which the AWJ technology for cutting alloy steel was used. During the experiments, some input factors were changed and measured parameters were subjected to different types of analysis using specialized software LabVIEW. Obtained data provide information about vibration and acoustic emission spectrum and enable us to find a dependency between the surface topography of cut materials and the emission spectrum of the accompanying physical phenomena arising during the AWJ process

Vibration emission as a potential source of information for abrasive waterjet quality process control

The paper deals with basic research of vibration generated at abrasive waterjet cutting of materials and their analysis of frequency spectrum in the plane cut. As an experimental material, stainless steel AISI 309 has been used. Experimentally controlled factor involved in the experiment was abrasive mass flow rate with values m a  = 250 and 400 g min−1 at a constant traverse speed v = 100 mm min−1. The vibrations were recorded during experimental cutting by sensors PCB IMI type 607A11 placed on experimental material along the cut at a distance of 50 mm from the cutting plane. Data collection was carried by NI PXI measurement system and frequency analyzer Microlog GX-S. Signal was evaluated by virtual instrument created in the object-programming environment LabView 8.5. Various sizes of amplitudes were observed depending on the distance of abrasive waterjet cutting process from the beginning of the cut. Two peaks of frequency bands have been also found: the first between 500 and 600 Hz and the other at approximately 12.5 kHz. Using this method is possible to ensure the determination of technology efficiency of the material removal process.Web of Science61-429428

Utjecaj brzine abrazivnog masenog protoka na vibracije kod prodiranja u materijal

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