Dynamic Behavior of a Thin-Walled Cylindrical Workpiece During the Turning-Cutting Process, Part 2: Experimental Approach and Validation

Abstract

Chatter vibrations in the cutting process have a central place in many machining applications. A numerical and theoretical approach of self-excited vibrations during the turning process of thin-walled hollow workpieces has been presented in the accompanying paper. Furthermore, a finite element model has been proposed to simulate the dynamics of the system. The response to a Dirac excitation, presented as Nyquist curves, is proposed in order to characterize the dynamics of the turning process and the stability criterion. In this the second part of two related papers, the main objective is to validate the simulated dynamic behavior by using the experimental approach. The results of machining tests performed on thin-walled tubes with steel and aluminum alloys, using different operating conditions (dimensions, geometry and setting conditions) are presented and discussed.

Contribution of computational mechanics in numerical simulation of machining and blanking: State-of-the-Art

“…Generally the evaluation of the quality of the surface generated or the level of vibrations of certain parts of the system are used. An example of such a stability criteria is propose by K. Mehdi in [33]. The time domain approach admits the introduction of a flexible workpiece, even in the region where the machining is done.…”

Variable Compliance-related Aspects of Chatter in Turning Thin-walled Tubular Parts

“…In a work of Arnold, 1961 [9] an experimental study of steel tubular parts (gun cradles) reveals multiple zones subject to vibrations during turning. In 2002, Mehdi et al [10,11] have investigated aluminum tubular parts turning via numerical or analytical part modeling and experimental tests for various cutting conditions. In 2011, Lorong et al [12] have presented an experiment accompanied with full time domain simulations featuring strong chatter and bringing forward the impact of the damping on the instability onset.…”

A parametric FEA system for fixturing of thin-walled cylindrical components

“…The dynamic behaviour of thin-walled cylindrical components under turning operation was studied by Mehdi et al (2002a,b), containing two parts: simulation (Mehdi et al, 2002a) and experiments (Mehdi et al, 2002b). The simulation part took into account the damping due to rubbing between the tool flank and the machined workpiece surface, and defined the parameters governing the stability of the cutting process in the case of thin-walled workpieces.…”