3613 KB36 KB199920252014Lemu, Hirpa G.Trzepieciński, Tomaszštevilka:1letnik:60str. 51-60, SI 11ISSN:0039-2480COBISSID:13373211URN:URN:NBN:SI:doc-CNH28DVMenZveza strojnih inženirjev in tehnikov Slovenije et al.Strojniški vestnikkoeficienti trenjapreoblikovanje pločevinesimulacije MKEtrenjezavorne letveFrictional conditions of AA5251 aluminium alloy sheets using drawbead simulator tests and numerical methods|This article presents research results on the effect of sheet metal surface roughness, lubricant conditions and sample orientation on the value of friction coefficient in the drawbead region of sheet metal-forming processes. Aluminium alloys with different temper conditions were used as test materials. The experimental results have ascertained several relationships showing the effect of surface profile and lubrication on the value of the friction coefficient. Based on experimental measurements, it may be concluded that the sample orientation and the lubrication conditions are crucial variables influencing the value of the coefficient of friction. Furthermore, a numerical model of the drawbead has been created in Msc.MARC Mentat software, and several simulations have been performed to study the stress/strain state in stretched sample during drawbead simulator tests. Both isotropic and anisotropic material models were used in the simulations taking into account the sample orientation with respect to the rolling direction of the sheetČlanek podaja rezultate raziskave vpliva površinske hrapavosti pločevine, pogojev mazanja in orientacije preskušanca na vrednost koeficienta trenja v območju zavorne letve pri postopkih preoblikovanja pločevine. Študija obravnava dva glavna problema: eksperimentalno raziskavo tornih pogojev pri pločevini iz aluminijaste zlitine s tornim preskusom v simulatorju zavorne letve, ter numerične simulacije na osnovi rezultatov tornega preskusa. Torni pogoji pločevine so bili preučeni s simulatorjem torne letve, ki je bil zgrajen po pristopu avtorja Nine (Nine, 1978). Različne tribološke razmere so bile ustvarjene s pomočjo valjev različne površinske hrapavosti. Za preskusni material je bila uporabljena aluminijeva zlitina AA5251, pripravljena z različnimi postopki toplotne obdelave. Glavni standardni 3D-parametri površinske hrapavosti so bili izmerjeni z inštrumentom Alicona InfiniteFocusTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo