Title: Ductile fracture mechanics and chip separation in cutting

Authors: Pedro A.R. Rosa, Paulo A.F. Martins, A.G. Atkins

Addresses: IDMEC, Instituto Superior Tecnico, TULisbon, Av. Rovisco Pais, Lisboa 1049-001, Portugal. ' IDMEC, Instituto Superior Tecnico, TULisbon, Av. Rovisco Pais, Lisboa 1049-001, Portugal. ' School of Construction Management and Engineering, Engineering Bldg, University of Reading, Reading RG6 6AY, UK

Abstract: The role of surface work in modelling metalworking processes in which separation takes place (machining, blanking, etc.) is discussed. Traditional algebraic and finite element analyses of such processes, incorporating only plastic flow and friction, are able to predict quite well the experimentally-observed material flow fields. However they always underestimate the experimental forces when independently-determined mechanical properties (flow stress, toughness and friction at the correct rates and temperatures) are employed. The deficiency in predicting the forces is directly connected to omitting work of surface formation in the analyses. A new experimental test piece is described for the independent determination of the specific work of separation. Values so obtained serve both as a check on the reasonableness of ductile fracture toughness determined from cutting tests and also for calibration of Finite Element Method (FEM) simulations of such processes.

Keywords: metal cutting; finite element method; FEM; ductile fracture; fracture toughness; specific work; chip separation; fracture mechanics; flow stress; friction; surface formation; simulation.

DOI: 10.1504/IJMMM.2007.015470

International Journal of Machining and Machinability of Materials, 2007 Vol.2 No.3/4, pp.335 - 346

Published online: 19 Oct 2007 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article