Photoelastic analysis of stresses and forces in steady cutting

Abstract

The results are presented of tests conducted at three different depths of cut and a velocity of 3.1 m/min on a work-hardening lead-alloy workpiece with a 10-degree-rake photoelastic tool. In addition to examining the behaviour of the chip-tool contact stresses, the paper considers the forces acting on the tool and distinguishes three areas: rake, nose, and flank. It evaluates the rake forces from the photoelastic results directly, estimates the nose forces by making certain assumptions with regard to the distribution of stresses, and neglects the stresses on the flank. The sum of the forces so obtained is then compared with the measured resultant cutting force; there is good agreement. There is a particularly significant observation which, contrary to previously published results, shows that the frictional stresses vary linearly in the so-called sticking zone and tend towards a constant only at relatively high depths of cut. This is discussed in relation to the general concept of plastic friction and the variation of the coefficient of friction on the rake face. The significance of the measured resultant coefficient of friction is also considered.

Fluid Mechanics Approach to Machining at High Speeds: Part Ii: A Potential Flow Model

“…Also, the shear stress distribution on the rake face of the tool is found to agree with the work reported by previous researchers (Rice et al, 1960;Usui and Takeyama, 1960;Amini, 1968).…”

“…Machining at High Speeds-Part II 505 predicted by the potential flow model in this work closely matches the shear stress distribution on the tool rake face obtained from the experimental work done by Amini (1968). Also, the proposed distribution partially matches the shear stress distribution on the tool rake face obtained from the experimental work conducted by Usui and Takeyama (1960) and Rice et al (1960).…”

A simple inverse procedure to determine heat flux on the tool in orthogonal cutting

“…In the past, many attempts to determine the local distribution of normal and shear stresses on the tool surface were carried out using photoelastic materials for either the tool or the workpiece, cutting tool materials with a well defined limit of elasticity and tools characterized by a reduced contact length including split-tools [10][11][12][13][14].…”

Analysis of adhered contacts and boundary conditions of the secondary shear zone

“…In that way, several studies are focused to determine the link between the distribution of the thermomechanical loading along the contact surface and the dry wear modes such as adhesion, abrasion, oxidation, delamination and more. In many experiments (based on analyses of the stress distribution [1][2][3][4][5][6], temperature [7][8][9] and worm tools [10]), analytical and numerical approaches, three contact regimes are usually stated; a perfectly sliding contact [11,12], an alternating sticking and sliding contact [13], and a fully sticking contact [14]. From a wear point of view, the different damage mechanisms are triggered at each contact regime according to the magnitude of sliding velocity, the pressure level and the temperature rise.…”