Mathematical Modelling of a Pneumo-Hydraulic Impulse Device for Vibration Turning
Abstract
This paper addresses the critical challenge of improving the machinability of difficult-to-cut advanced materials through radial vibration-assisted turning. Traditional piezoelectric or mechanical vibrators suffer from micro-stroke decay or severe inertial limitations under heavy technological cutting loads. To resolve this bottleneck, a compact pneumo-hydraulic impulse multiplier device equipped with a single-stage parametric pressure pulse generator is investigated via a non-linear fluid-structure interaction framework solved through explicit Euler integration. Initial simulations revealed that a conventional high-inertia steel pusher (0.85 kg) paired with standard cylindrical springs induces a destructive “static lock-up” condition due to continuous unrelaxed kinetic energy accumulation. To bring the drive into its optimal operating window, structural modernization was executed by substituting the reciprocating components with a lightweight titanium alloy (Ti-6Al-4V Grade 5) and integrating a high-stiffness slotted spring. The upgraded simulation demonstrates a successful transition into a critically damped aperiodic operating regime. The modernized drive completely eliminates parasitic tool rebound, achieving perfectly repeatable pressure cycles reaching 14.8 MPa and a highly stable cutter vibration amplitude of 0.15–0.18 mm at operating frequencies up to 250 Hz. This provides a predictive, numerically validated foundation for high-frequency vibration turning utilizing standard shop-floor pneumatic supply networks.