Testing of the heating element integrated into the honeycomb sandwich structure for active thermography inspection

2020 ◽  
pp. 109963622092788
Author(s):  
Václav Tříska ◽  
Tomáš Chlebeček ◽  
Jakub Hnidka ◽  
Karel Maňas
Keyword(s):  
Sandwich Structure ◽  
Bending Strength ◽  
High Sensitivity ◽  
Carbon Composite ◽  
Heating Element ◽  
Health Examination ◽  
Thermal Excitation ◽  
Internal Excitation ◽  
Honeycomb Sandwich ◽  
Strength And Stiffness

The honeycomb sandwich structures with carbon composite face sheets combined with aluminium or Nomex® honeycomb core are extensively used in the aircraft airframe structure. They provide some key benefits over conventional structures such as increased bending strength and stiffness combined with low weight. However, they show high sensitivity to a certain type of damage, such as object impact, mishandling, etc. Non-destructive inspection methods are needed for a structural health examination. Active infrared thermography is one of them. The quality of the inspection and defect detection depends heavily on the proper application of the external thermal excitation. This paper presents a concept of the sandwich structure with internal excitation by means of an integrated thin-film resistive heating element.

Mechanical Property Analysis and Numerical Simulation of Honeycomb Sandwich Structure’s Core

2013 ◽  
Vol 631-632 ◽  
pp. 518-523 ◽  
Author(s):  
Xiang Li ◽  
Min You
Keyword(s):  
Numerical Simulation ◽  
Elastic Constants ◽  
Sandwich Structure ◽  
Optimization Design ◽  
Simulation Analysis ◽  
Finite Element Program ◽  
Honeycomb Sandwich ◽  
Calculation Results ◽  
Element Program ◽  
Typical Satellite

Owing to the lack of a good theory method to obtain the accurate equivalent elastic constants of hexagon honeycomb sandwich structure’s core, the paper analyzed mechanics performance of honeycomb sandwich structure’s core and deduced equivalent elastic constants of hexagon honeycomb sandwich structure’s core considering the wall plate expansion deformation’s effect of hexagonal cell. And also a typical satellite sandwich structure was chose as an application to analyze. The commercial finite element program ANSYS was employed to evaluate the mechanics property of hexagon honeycomb core. Numerical simulation analysis and theoretical calculation results show the formulas of equivalent elastic constants is correct and also research results of the paper provide theory basis for satellite cellular sandwich structure optimization design.

High-Frequency Vibration Response of Metal Honeycomb Sandwich Structure

2009 ◽  
Vol 79-82 ◽  
pp. 1727-1730 ◽  
Author(s):  
Xiao Dong He ◽  
Xiang Hao Kong ◽  
Li Ping Shi ◽  
Ming Wei Li
Keyword(s):  
High Frequency ◽  
Sandwich Structure ◽  
Dynamic Pressure ◽  
Vibration Response ◽  
Element Analysis ◽  
High Frequency Vibration ◽  
Honeycomb Sandwich ◽  
Vibration Experiment ◽  
Aerial Vehicle ◽  
Honeycomb Sandwich Structure

ARMOR TPS panel is above the whole ARMOR TPS, and the metal honeycomb sandwich structure is the surface of the ARMOR TPS panel. So the metal honeycomb sandwich structure plays an important role in the ARMOR TPS, while it bears the flight dynamic pressure and stands against the flight dynamic calefaction. So the active environment of metal honeycomb sandwich structure is very formidable. We have to discuss any extreme situation, for reason of making sure aerial vehicle is safe. And high-frequency vibration is one of active environment. In this paper we have analyzed high-frequency vibration response of metal honeycomb sandwich structure. We processed high-frequency vibration experiment by simulating true aerial environment. Sequentially we operated high-frequency vibration experiment of metal honeycomb sandwich structure with cracks, notches and holes. Then finite-element analysis was performed by way of validating the experiment results. Haynes214 is a good high temperature alloy material of both face sheet and core at present, so we choose it in this paper.

Numerical Analysis and Mechanical Properties of Nomex™ Honeycomb Core

2017 ◽  
Author(s):  
Yue Liu ◽  
Weicheng Gao ◽  
Wei Liu ◽  
Zhou Hua
Keyword(s):  
Compressive Strength ◽  
Cell Walls ◽  
Mechanical Response ◽  
Compressive Loading ◽  
Fe Model ◽  
Honeycomb Core ◽  
Practical Applications ◽  
Honeycomb Sandwich ◽  
Nomex Honeycomb ◽  
Strength And Stiffness

This paper presents an investigation on the mechanical response of the Nomex honeycomb core subjected to flatwise compressive loading. Thin plate elastic in-plane compressive buckling theory is used to analyze the Nomex honeycomb core cell wall. A mesoscopic finite element (FE) model of honeycomb sandwich structure with the Nomex honeycomb cell walls is established by employing ABAQUS/Explicit shell elements. The compressive strength and compressive stiffness of Nomex honeycomb core with different heights and thickness of cell walls, i.e. double cell walls and single cell walls, are analyzed numerically using the FE model. Flatwise compressive tests are also carried out on bare honeycomb cores to validate the numerical method. The results suggest that the compressive strength and compression stiffness are related to the geometric dimensions of the honeycomb core. The Nomex honeycomb core with a height of 6 mm has a higher strength than that of 8 mm. In addition, the honeycomb core with lower height possesses stronger anti-instability ability, including the compressive strength and stiffness. The proposed mesoscopic model can effectively simulate the crushing process of Nomex honeycomb core and accurately predict the strength and stiffness of honeycomb sandwich panels. Our work is instructive to the practical applications in engineering.

Honeycomb-Cored Sandwich Structure Composites

2010 ◽  
pp. 223-235
Keyword(s):  
Composite Materials ◽  
Sandwich Structure ◽  
Complex Structure ◽  
Failure Mechanisms ◽  
Resin System ◽  
Lower Weight ◽  
Film Adhesive ◽  
Adhesive Prepreg ◽  
Honeycomb Sandwich ◽  
Honeycomb Sandwich Structure

Abstract The honeycomb sandwich structure composite is a very efficient and complex structure widely used in the aircraft industry. Honeycomb-cored sandwich panels increase part stiffness at a lower weight than monolithic composite materials. This chapter describes the analysis of the intermingling of the film adhesive/prepreg resin system. It discusses the causes and effects of honeycomb core movement, which results in core crush. The chapter also explains the formation of a void in honeycomb composites and the failure mechanisms in honeycomb sandwich structure composites.

Flexural properties of notched carbon–aramid hybrid composite laminates

2019 ◽  
Vol 53 (28-30) ◽  
pp. 4137-4148 ◽  
Author(s):  
TA Sebaey ◽  
Ahmed Wagih
Keyword(s):  
Hybrid Composite ◽  
Composite Laminates ◽  
High Sensitivity ◽  
Flexural Properties ◽  
Bending Tests ◽  
Specific Strength ◽  
Four Point Bending ◽  
Hybrid Laminates ◽  
Minimal Damage ◽  
Strength And Stiffness

Hybrid composite laminates are currently receiving researchers’ attention due to their specific advantages in designing laminates with improved specific strength and stiffness. One of the main disadvantages of polymeric laminated composites is their high sensitivity to notches, which cannot be avoided in design. This paper presents a comparison between two common hybridization techniques, namely sandwich and intra-ply hybridization. The study adopts experimental observations to investigate the influence of hybridization method on the flexural properties of notched carbon–aramid hybrid laminates. After four-point bending tests, the results show that the damage nature in both laminates is different. A catastrophic damage is observed for intra-ply hybrid laminates, while sandwich laminates show progressive damage. In terms of the strength, sandwich specimens show 1.3 times higher specific strength, compared to intra-ply specimens. Moreover, the bottom layers of the laminate manufactured in the sandwich fashion show minimal damage due to the high capability of the aramid/epoxy core to absorb the energy in deformation and concentrate the damage at the top layers (the compression side).

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