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

Nomex honeycomb composites (NHCs) are commonly used in various industrial sectors such as aerospace and automotive sectors due to their excellent material properties. However, when machining this type of structure, problems can arise due to significant cutting forces and unwanted cell vibrations. In order to remedy these shortcomings, this study proposes to integrate RUM (rotary ultrasonic machining) technology, which consists of applying ultrasonic vibrations along the axis of rotation of the cutter. To fully understand the milling process by ultrasonic vibrations of the NHC structure, a 3D numerical finite element model is developed using Abaqus/Explicit software. The results of the comparative analysis between the components of the simulated cutting forces and those from the experiment indicate a close agreement between the developed model and the experimental results. Based on the developed numerical model, this study comprehensively analyzes the influence of the ultrasonic vibration amplitude on various aspects, such as stress distribution in the cutting zone, chip size, the quality of the machined surface and the components of the cutting force. Ultimately, the results demonstrate that the application of ultrasonic vibrations leads to a reduction of up to 50% in the components of the cutting force, as well as an improvement in the quality of the machined surface and a reduction in the size of chips.

Modeling and numerical simulation of the chip formation process when machining Nomex.

The machining of Nomex honeycomb structures represents a technical and scientific barrier for aeronautical applications. The difficulties encountered during the machining of this type of material are linked to the low density of Nomex paper, and to the low thickness of the walls forming the honeycomb cells of this type of structure. In this work, a finite element calculation code "ABAQUS`- EXPLICIT" was used to optimize and analyze the machining by milling of Nomex honeycomb structures. The main objective of this work is to study the influence of the machining conditions on the cutting forces, and the morphology of the chips.