Predictive modeling and simulation of two-dimensional cyclic chip formation process in dry machining using slip-line models.

摘要

New slip-line models for machining with restricted contact grooved tools and with rounded cutting edge tools are presented in this dissertation. Oxley's predictive machining theory has also been integrated into the new slip-line model. Matrix technique for numerically solving slip-line problems has been employed in the mathematical solution of the slip-line field. A system of equations has been developed for determining the shape of the initial slip-line. Other equations are derived to mathematically determine the output parameters of the universal slip-line.;Four major machining parameters (cutting forces, chip thickness, chip up-curl radius and chip back-flow angle) are predicted for variations in as well as for variations in four major tool and chip-groove geometric parameters. Also, a new methodology is developed for predicting the actual tool-chip interface friction from this predictive model using the actual chip geometry. The results obtained from this work also help to study the stress and friction on the tool-chip interface. By using the predicted effect of the hydrostatic pressure and tool-chip friction and experimental chip geometry, the actual boundary conditions of pressure and friction can be obtained.;The effect of cutting edge roundness as well as secondary rake face on cutting forces and chip geometry has been investigated using the new slip-line model. The variation in cutting forces and chip geometry is representative of the different slip-line field and is primarily due to the varying tool-groove geometry and cutting conditions, allied with the work material property.;Experimental work has been conducted to validate the new slip-line model integrated with Oxley's machining theories. The major criteria of validation are cutting forces. Also, chip formation and chip geometry are observed using high speed filming technique.