Numerical Simulation of Rotary Ultrasonic Machining of the Nomex Honeycomb Composite Structure

Abstract

Nomex honeycomb composite (NHC) cores have seen significant growth in recent years, particularly in the aeronautics, aerospace, naval and automotive industries. This development presents significant challenges in terms of improving machining quality, requiring the use of specialized cutting tools and favorable cutting techniques. In this context, experimental studies have been carried out to highlight the characteristics of the milling of NHCs by rotary ultrasonic machining (RUM). However, the rapid motion of the cutting tool and the inaccessibility of the tool/part interface prevent the visualization of the chip formation process. For this purpose, a three-dimensional numerical model for milling the NHC structure using RUM technology was developed by Abaqus Explicit software. On the basis of this model, the components of the cutting force, the quality of the machined surface and the chip accumulation in front of the cutting tool were analyzed. The numerical results agree with the experimental tests, demonstrating that the use of RUM technology effectively reduces the cutting force components. An in-depth analysis of the influence of feed component Fy on the quality of the generated surface was carried out, revealing that the surface quality improved with low values of feed component Fy. Furthermore, the impact of ultrasonic vibrations on the accumulation of chips in front of the cutting tool is particularly optimized, in particular for large amplitudes.

Enhancing the Machining Performance of Nomex Honeycomb Composites Using Rotary Ultrasonic Machining: A Finite Element Analysis Approach

“…This RP is essential for establishing the cutting conditions and evaluating the cutting forces during the milling process. The movement of the cutting tool can be described in terms of global coordinates xyz by the following equations [8]:…”

“…During the experimental phase, the cutting force components, namely F y (feed component along Y) and F x (cutting component along X), are measured using the KISTLER-9256C2 dynamometer. A benefit of this technique is that it is possible to calculate the average value in both directions using the following formulas [8,21]:…”

“…Furthermore, the use of ultrasonic vibration leads to a significant simplification of the complexity inherent in the machining of this structure, thus offering a promising solution to address the challenges associated with this process. The precise control of cutting conditions, such as the frequency, amplitude and direction of ultrasonic vibrations, is of crucial importance in the processing process [8]. This control capability makes it possible to effectively regulate the interaction between the tool and the workpiece, thus leading to a better machinability of the material [9][10][11].…”