Optimising external turning tool choice using AHP and ELECTRE II methods

Abstract

Original scientific paper It is preferable to remove as much raw material in as short time as possible when processing materials using rough turning methods. Selecting the correct cutting tool at the beginning of the process is very important as this reduces the amount of material requiring later processing, in turn reducing the number of turning tools required, the number of tool changes and the total time taken to make a piece. In this paper, we present a system for selecting the best tools for external longitudinal turning. We take into account the characteristics of the machine, the power needed for cutting, the geometry and technological characteristics of the tools, and the machining parameters. Selection of the best tool for rough machining is made based on the processing time, the percentage of material to be cut, the cost of the tools and the number of tool changes. We ranked eight tools and used the analytical hierarchy process (AHP) method for multi-criteria optimisation then evaluated the results using ELECTRE II methods. The weight criteria were estimated using Saaty's pairwise comparison scale. Keywords: analytic hierarchy process; ELECTRE II method; multi-criteria decision-making; tool selection Izbor optimalnog alata za vanjsko tokarenje pomoću AHP i ELECTRE II metodeIzvorni znanstveni članak Prilikom obrade vanjskim grubim tokarenjem poželjno je skinuti što više materijala sa sirovog komada u što kraćem vremenu. Vrlo je važno izabrati tokarski nož koji prvi započinje obradu, kako bi ostatak materijala za kasniju obradu bio što manji. Time se smanjuje ukupno potrebni broj alata za tokarenje, broj izmjena alata te ukupno vrijeme izrade komada. U radu je prikazan sistem za izbor najpovoljnijeg alata za vanjsko uzdužno tokarenje uz uvažavanje karakteristika stroja, snage potrebne za rezanje, geometriju i tehnološke karakteristike alata te parametara obrade. Izbor najoptimalnijeg alata za grubu obradu izvršen je prema kriterijima vrijeme obrade, postotak odrezanoga materijala, cijena alata po reznoj oštrici te broju prolaza alata. Kod rangiranja rezultata obrade za 8 alata korištena je metoda za višekriterijsku optimizaciju AHP, a rezultati su dodatno vrednovani po ELECTRE II metodi. Vrijednosti težina kriterija procijenjene su prema Saty-jevoj ljestvici usporedbe kriterija u parovima.