Predicting the strain rate in the zone of intense shear in which the chip is formed in machining from the dynamic flow stress properties of the work material and the cutting conditions

Abstract

In previous applications of an approximate machining theory in which account is taken of the strain rate and temperature dependence of the work material flow stress properties it has been found necessary to use an empirical relation to determine the maximum value of the maximum shear strain rate in the chip formation zone. In this paper the machining theory is further developed so that this strain rate can be obtained as part of the solution. Predicted values found in this way are shown to be in excellent agreement with the rather limited number of experimental strain rate results which are available. The paper ends by showing that if the work material is allowed to approach the ideal constant flow stress material usually assumed in slip-line field theory then the predicted strain rates become extremely large. However, it is still found necessary in calculating the corresponding hydrostatic stresses to use the stress equilibrium equations for a variable flow stress material as the variable flow stress terms do not diminish as rapidly as might have been expected.

Recent Advances in Micro/Nano-cutting: Effect of Tool Edge and Material Properties

“…After that, many slip-line models have been proposed. In 1977, the parallel-sided shear zone theory proposed by Oxley et al [16] is an important progress in modeling cutting process, as shown in Fig. 2.…”

Experimental study of coated carbide tools behaviour: application for Ti-5-5-5-3 turning

“…A high rake angle generates a shear angle increasing and so a reduction of cutting force. This phenomenon can be illustrated by the Oxley and Hasting (1977) model. To conclude, the rake angle choice must be a compromise between a cutting force reduction and a better tool mechanical aspect.…”

“…The rake angle increasing reduces the effective shear angle and friction force. Oxley and Hasting (1977) demonstrate in their model that the cutting temperature is function of shear flow stress, friction force, chip velocity and shear velocity. In fact, whatever the cutting speed, a cutting forces decreasing reduce the cutting temperature.…”

Modelling of the Relationship of Adiabatic Shear and Cutting Conditions for Higher Cutting Speed Ranges

“…For the width of the primary shear zone, the study of Oxley and Hastings [33] shows that the ratio of it and the length of shear plane is 5.9 for carbon steel; thus, there is,…”