1389 KB36 KB199920252015Gao, YayunWan, LeiWang, Dazhongštevilka:3letnik:61str. 157-166, SI 32ISSN:0039-2480COBISSID:13935899URN:URN:NBN:SI:doc-CS1TFVCGenZveza strojnih inženirjev in tehnikov Slovenije et al.Strojniški vestnikdeformacijsko utrjanjefinite element methodgeometrija robov orodijmetoda končnih elementovnabiranje materialapreostale napetostiproces odrezavanjaučinek toplotnega mehčanjaInvestigations on the effects of different tool edge geometries in the finite element simulation of machining|This work focuses on the effects of cutting edge geometries on dead metal zone formation, as well as stress and temperature distributions in orthogonal cutting of P20 material using finite element method (FEM) simulation with sharp, chamfered, double chamfered and blunt tools. The cutting process is simulated with Arbitrary Lagrangian-Eulerian (ALE) approach in ABAQUS/Explicit. The simulation results suggest that the tool edge geometry influences the shape of dead metal zone considerably, while having little influence on the chip formation. An analysis of thermo-mechanical coupling was also conducted, and the results show that the stress distribution is affected by the temperature distribution and cutting speed because of the thermal softening effect and the strain rate hardening. A common analytical model is introduced to predict the residual stress, and equivalent Mises residual stresses are all calculated with four different tools to suggest that the tool edge geometry has a significant effect on the residual stress. The experiments are conducted using a CNC with former four kinds of tools at a speed of 480 m/min, and the residual stresses beneath the machined surface were measured with X-ray diffraction and electro-polishing techniques, and a chamfer tool at three different cutting speeds (250, 600 and 1000 m/min) to obtain the forces. The machining forces in both the cutting and thrust directions increases as the chamfer angle increases and decreases as the cutting speed increasesNamen raziskave je opredelitev vplivov različnih geometrij rezalnega roba orodja na proces odrezavanja, kamor spadajo npr. nabiranje materiala obdelovanca pod posnetim robom (območje mrtve kovine), porazdelitev napetosti in temperature pri štirih različnih geometrijah roba, in še posebej porazdelitev preostalih napetosti, ki lahko odraža kakovost obdelane površine. Rezultati raziskave lahko pomagajo pri iskanju pravega roba za obdelavo določenega materiala. Najprej je predlagan nov analitični model in nato so analizirani postopki odrezavanja z različnimi geometrijami robov. V drugi fazi je bila uporabljena metoda končnih elementov za simulacijo procesa odrezavanja z različnimi geometrijami rezalnega roba pri različnih rezalnih hitrostih, rezultat pa je porazdelitev hitrosti, napetosti in temperature. Končno so bili opravljeni še eksperimenti z različnim kotom posnetja pri različnih rezalnih hitrostih za validacijo rezultatov simulacijeTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo