Study on ultrasonic vibration–assisted cutting of Nomex honeycomb cores

Coefficients of thermal and moisture expansion (CTE and CME) can be predicted for many composite laminates and sandwich panels. Core and adhesive properties, such as geometry and stiffness are important variables. Laminate theory is augmented with a modified model for anisotropic core properties to predict the CTE and CME of sandwich panels. Procedures to measure both CTE and CME are described. Since these are thermodynamic properties, methods to obtain equilibrium moisture strains are needed. Results are given for CFRP facesheets with Al and NOMEX honeycomb cores, and for woven Kevlar facesheets with Al cores. Agreement with predictions is good and depends highly on knowledge of properties of all constituents.

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A Novel Ultrasonic Trepanning Method for Nomex Honeycomb Core

Applied Sciences ◽

10.3390/app11010354 ◽

2020 ◽

Vol 11 (1) ◽

pp. 354

Author(s):

Dingyi Sun ◽

Renke Kang ◽

Yidan Wang ◽

Jialin Guo ◽

Zhigang Dong

Keyword(s):

Theoretical Model ◽

Ultrasonic Vibration ◽

High Speed ◽

Vertical Surface ◽

Core Material ◽

Honeycomb Core ◽

Dimensional Error ◽

Characteristic Structure ◽

Nomex Honeycomb

The vertical surface is a common and typical characteristic structure among Nomex honeycomb core components. However, the conventional high-speed milling and ultrasonic cutting struggle to meet the high-quality machining requirements of a vertical surface. In this study, an ultrasonic trepanning method is proposed and a special ultrasonic trepanning tool is developed, aiming to improve the machining quality of the vertical surface. The trepanning quality of the vertical surface is further studied from the aspects of dimensional error and trepanning incision quality. Based on the kinematic characteristics of ultrasonic trepanning, a theoretical model of dimensional error in trepanning is established. Meanwhile, the influence of ultrasonic vibration on the trepanning process is analyzed, and the result shows that ultrasonic vibration significantly improves the equivalent elastic constant of the honeycomb core material. The theoretical model is proposed to predict the trepanning dimensional error, which is verified by experiment. The effectiveness of the ultrasonic vibration on the incision quality is verified by several experiments, and the quantitative analysis results demonstrate that ultrasonic vibration significantly improves the trepanning quality of the vertical surface.

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A novel method of blade-inclined ultrasonic cutting Nomex honeycomb core with straight blade

Journal of Manufacturing Science and Engineering ◽

10.1115/1.4049475 ◽

2020 ◽

pp. 1-34

Author(s):

Yidan Wang ◽

Renke Kang ◽

Zhigang Dong ◽

Xuanping Wang ◽

Dehong Huo ◽

...

Keyword(s):

Cutting Forces ◽

Cutting Tool ◽

Honeycomb Core ◽

Straight Blade ◽

Machining Quality ◽

Cutting Geometry ◽

Novel Method ◽

Nomex Honeycomb ◽

Honeycomb Cores ◽

Ultrasonic Cutting

Abstract Ultrasonic cutting with a straight blade is an advanced cutting method for Nomex honeycomb core. However, crushing has generally been observed on the machining surface of the honeycomb core in ultrasonic cutting (UC). In this paper, aiming at avoiding crushing, a new blade-inclined ultrasonic cutting (BIUC) method is proposed to decrease the geometric interference between the cutting tool and the honeycomb cores. The cutting geometry systems of UC and BIUC with a straight blade are systematically established to study the effect of cutting geometry on the machining quality. The crushing degrees caused by the major flank under different tool orientations in UC and BIUC are analyzed. The causes of crushing during the machining of the honeycomb core were revealed from aspects of machining quality, cutting force and geometric interference between the major flank and the material. Experiments on quantitive analysis of crushing and cutting forces verify that the BIUC method is able to avoid crushing by controlling the cutting angle. This paper provides a new method for solving the crushing problem in machining honeycomb core with the straight blade.

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Optimization of the Composite Airplane Fuselage for an Optimum Structural Integrity

Volume 1: Advances in Aerospace Technology ◽

10.1115/imece2018-88215 ◽

2018 ◽

Cited By ~ 1

Author(s):

Athreya Nagesh ◽

Ola Rashwan ◽

Ma’moun Abu-Ayyad

Keyword(s):

Carbon Fiber ◽

Static Loading ◽

Composite Laminates ◽

Structural Integrity ◽

Carbon Composite ◽

The Finite Element Method ◽

Nomex Honeycomb ◽

Honeycomb Cores ◽

Laminate Thickness ◽

Airplane Fuselage

The newly developed airplanes are using composite laminates to replace the metal alloys for different components, such as the fuselage and the wings. The major advantage of the composite materials is to reduce structural weight which results in reducing the fuel consumption. The aim of this project is to investigate the structural integrity of an airplane fuselage, which uses various types of carbon composite laminates under the static loading of the cabin pressurization. The research is performed using the finite element method and the HYPERMESH commercial software with a composite tool to change the thickness and the orientation of carbon fiber laminates used in the facesheet of the sandwich structure. Three different orientations/stacking sequence of the HexPly 8552 AS4 carbon fibers with two honeycomb cores: Hexagonal Al and Nomex. The results show that the composite material using the HexPly 8552 carbon fiber oriented at angle 30 and angle 45 and the Nomex Honeycomb core of a total laminate thickness of 15.875mm outperform all other thicknesses and orientations in regards to the static loading failure.

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Effect of phenolic resin thickness on frequency-dependent dynamic mechanical properties of Nomex honeycomb cores

Composites Part B Engineering ◽

10.1016/j.compositesb.2018.08.126 ◽

2018 ◽

Vol 154 ◽

pp. 285-291 ◽

Cited By ~ 8

Author(s):

Yong Zhou ◽

Qinglin Wang ◽

Yunli Guo ◽

Yongzheng Xu ◽

Xiaosu Yi ◽

...

Keyword(s):

Mechanical Properties ◽

Phenolic Resin ◽

Dynamic Mechanical Properties ◽

Frequency Dependent ◽

Dynamic Mechanical ◽

Nomex Honeycomb ◽

Honeycomb Cores

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Ultrasonic Vibration Assisted Cutting of Nomex Honeycomb Core Materials

International Journal of Precision Engineering and Manufacturing ◽

10.1007/s12541-019-00038-8 ◽

2019 ◽

Vol 20 (1) ◽

pp. 27-36 ◽

Cited By ~ 4

Author(s):

Dao-Hui Xiang ◽

Bang-Fu Wu ◽

Yun-Long Yao ◽

Bo Zhao ◽

Jin-Yuan Tang

Keyword(s):

Ultrasonic Vibration ◽

Honeycomb Core ◽

Nomex Honeycomb ◽

Core Materials

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In-plane compression modulus and strength of Nomex honeycomb cores

Journal of Sandwich Structures & Materials ◽

10.1177/10996362211021888 ◽

2021 ◽

pp. 109963622110218

Author(s):

Mustafa O Ayanoglu ◽

Mohammad Tauhiduzzaman ◽

Leif A Carlsson

Keyword(s):

Bending Strength ◽

Compression Modulus ◽

Thin Wall ◽

Test Results ◽

Average Modulus ◽

Shear Type ◽

Plane Compression ◽

Nomex Honeycomb ◽

Honeycomb Cores ◽

Vertical Cell

The stress-strain response and deformation mechanism of a range of Nomex honeycomb cores tested under in-plane compression has been examined experimentally. The cores with a thin wall displayed extensive bending deformation of the cell walls inclined to the horizontal (loading is vertical) and failed in bending. The cores with thicker walls failed by a shear-type instability of the cells indicated by tilting of vertical cell wall segments. The failure strain decreased with increasing core density. The modulus and compressive strength of the core were compared to micromechanical predictions. Normalized modulus and strength values varied between the various cores. The average modulus and strength results allow backing out of the modulus and bending strength of the Nomex paper. The results were in reasonable agreement with published tensile test results and composite micromechanics.

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