scholarly journals Mechanical Properties and Fatigue Performances on Sandwich Structures with CFRP Skin and Nomex Honeycomb Core

2017 ◽  
Vol 54 (1) ◽  
pp. 67-72 ◽  
Author(s):  
Sebastian Marian Zaharia ◽  
Mihai Alin Pop ◽  
Augustin Semenescu ◽  
Bogdan Florea ◽  
Oana Roxana Chivu
Keyword(s):  
Mechanical Properties ◽  
Composite Structures ◽  
Sandwich Structures ◽  
Industrial Applications ◽  
Accelerated Testing ◽  
Test Time ◽  
Honeycomb Core ◽  
Main Indicator ◽  
Carbon Fibre Reinforced Polymer ◽  
Nomex Honeycomb

Composite sandwich structures with Nomex honeycomb core are commonly used in industrial applications. This paper was focused on the study of the mechanical properties of sandwich structures with CFRP (carbon fibre reinforced polymer) skin and a phenolic resin-impregnated aramid paper core, known as Nomex. The paper analyzes behaviour and determines the mechanical properties of the CFRP-Nomex specimens to different types of tests, such as: three - point bending, compression, impact. The exceptional fatigue resistance of the composite structures is responsible for their success in a variety of industrial applications. For this reason, in this paper were implemented accelerated testing techniques for CFRP-Nomex sandwich structures, resulting in a significant reduction of the test time (of 13.9 times). The main indicator that was determined using the accelerated testing methodology was the mean life that has value of 268554 cycles.

Effect of Core Thickness and Intermediate Layers on Mechanical Properties of Polypropylene Honeycomb Multi-Layer Sandwich Structures

2014 ◽  
Vol 59 (1) ◽  
pp. 11-16 ◽  
Author(s):  
J. Arbaoui ◽  
Y. Schmitt ◽  
J.-L. Pierrot ◽  
F.-X. Royer
Keyword(s):  
Mechanical Properties ◽  
Sandwich Structures ◽  
Bending Test ◽  
Honeycomb Core ◽  
Lightweight Construction ◽  
Specific Strength ◽  
High Specific Strength ◽  
Intermediate Layers ◽  
Core Thickness ◽  
Strength And Stiffness

Abstract Sandwich structures are widely used in lightweight construction especially in aerospace industries because of their high specific strength and stiffness. This paper investigates the effect of core thickness and intermediate layers on the mechanical properties of a polypropylene honeycomb core/composite facing multilayer sandwich structure under three points bending. We developed a theoretical model which makes it possible to calculate the shear properties in multi-cores. The results obtained by this model are agreed with our experimental results, and the results obtained with bending test showed that the mechanical properties of the composite multilayer structures increase with core thickness and intermediate layers.

scholarly journals Basic Mechanical Properties of TEEK Polyimide-Foam and TEEK-Filled Aramid Honeycomb Core-Materials for Sandwich Structures

2005 ◽  
Vol 54 (1) ◽  
pp. 97-103
Author(s):  
Akitsu KUWABARA ◽  
Megumi OZASA ◽  
Toshiyuki SHIMOKAWA ◽  
Naoyuki WATANABE ◽  
Kazuhiko NOMOTO
Keyword(s):  
Mechanical Properties ◽  
Sandwich Structures ◽  
Honeycomb Core ◽  
Core Materials

Characterization of Nomex honeycomb core constituent material mechanical properties

2014 ◽  
Vol 117 ◽  
pp. 255-266 ◽  
Author(s):  
Rene Roy ◽  
Sung-Jun Park ◽  
Jin-Hwe Kweon ◽  
Jin-Ho Choi
Keyword(s):  
Mechanical Properties ◽  
Honeycomb Core ◽  
Constituent Material ◽  
Nomex Honeycomb

scholarly journals Review of Testing Methods Dedicated for Sandwich Structures with Honeycomb Core

2019 ◽  
Vol 2019 (2) ◽  
pp. 1-14
Author(s):  
Arnold Jędral
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Composite Structures ◽  
Core Material ◽  
Honeycomb Core ◽  
Testing Methods ◽  
Professional Literature ◽  
Sandwich Type ◽  
American Society ◽  
Sandwich Materials

Abstract This paper is a review of testing methods dedicated for sandwich type composite structures with honeycomb core. First, information about the composition of sandwich materials structures, their properties, types of core materials and applications in the industry is presented. Mechanical properties were compared in the case of different types of the core material. Later, tests methods needed to describe properties of those materials and normalization organizations which create them were mentioned. The testing methods were divided into two groups: mechanical and physicochemical tests. Mechanical properties are: compressive strength (two types of test), edge compressive strength, shear strength (in two directions) and tension strength (two types of test). Physicochemical properties are: material density, water migration, water absorption and thermal conductivity. Testing methods were described according to American Society for Testing and Materials (ASTM) standards. This article is based on professional literature and the author’s experience.

scholarly journals Vibration behaviour of a bio-composite sandwich with auxetic core

2019 ◽  
Vol 283 ◽  
pp. 09004
Author(s):  
Khawla Essassi ◽  
Jean-Luc Rebiere ◽  
Abderrahim El Mahi ◽  
Mahamane Toure ◽  
Mohamed amine Ben Souf ◽  
...  
Keyword(s):  
Composite Structures ◽  
Sandwich Structures ◽  
Dynamic Properties ◽  
Flexural Vibration ◽  
Flax Fibre ◽  
Sandwich Composite ◽  
Fibre Reinforcement ◽  
Damping Properties ◽  
Honeycomb Core ◽  
Composite Sandwich

This paper describes the flexural vibration and damping performances of an eco-composite sandwich structure with re-entrant honeycomb core. The main objective of this study is to analyse the effect of flax fibre reinforcement composite and the densities of the auxetic core on the dynamic properties of the sandwich structures. The damping properties and the sandwich stiffness are determined in bending beams for different free lengths in a clamped-free configuration. Firstly, the dynamic properties of the skins were investigated in order to develop the evolution of mechanical properties as well as damping coefficient for each material. Then, the same characterization was tested on the sandwich structures with different core densities. The results obtained showed that both core densities and flax fibre as reinforcement plays a major role on the dynamic properties of the sandwich composite structures.

Basic mechanical properties of balloon-type TEEK-L polyimide-foam and TEEK-L filled aramid-honeycomb core materials for sandwich structures

2005 ◽  
Vol 14 (4) ◽  
pp. 343-363 ◽  
Author(s):  
Akitsu Kuwabara ◽  
Megumi Ozasa ◽  
Toshiyuki Shimokawa ◽  
Naoyuki Watanabe ◽  
Kazuhiko Nomoto
Keyword(s):  
Mechanical Properties ◽  
Sandwich Structures ◽  
Honeycomb Core ◽  
Core Materials

Effects of honeycomb core damage on the performance of composite sandwich structures

2019 ◽  
Vol 54 (16) ◽  
pp. 2159-2171
Author(s):  
William T King ◽  
William E Guin ◽  
J Brian Jordon ◽  
Mark E Barkey ◽  
Paul G Allison
Keyword(s):  
Finite Element ◽  
Shear Modulus ◽  
Composite Structures ◽  
Sandwich Structures ◽  
Honeycomb Core ◽  
Element Analysis ◽  
Composite Sandwich ◽  
Core Damage ◽  
Composite Sandwich Structures ◽  
Aluminum Honeycomb

This work presents an experimental and numerical investigation of the effects of pre-existing core damage on aluminum honeycomb core composite sandwich structures. Quasi static flexural and compression experiments were performed, where the effects of core damage on the shear modulus and Young's modulus were quantified. In addition, finite element analysis was performed on the sandwich structures to elucidate the effects of the core damage on the structural response. Comparisons of experimental and finite element responses are presented for sandwich structures consisting of carbon fiber facesheets and an aluminum honeycomb core. The pre-existing core damage is observed to cause up to an 8% reduction in shear modulus and a 9% reduction in elastic modulus. It is also determined that the presence of pre-existing core damage results in an asymmetrical compressive load distribution in the composite structures.

scholarly journals Anti-Inflammatory Properties of Injectable Betamethasone-Loaded Tyramine-Modified Gellan Gum/Silk Fibroin Hydrogels

Biomolecules ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1456
Author(s):  
Isabel Matos Oliveira ◽  
Cristiana Gonçalves ◽  
Myeong Eun Shin ◽  
Sumi Lee ◽  
Rui Luis Reis ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Mechanical Properties ◽  
Silk Fibroin ◽  
Therapeutic Efficacy ◽  
Composite Structures ◽  
Gelation Time ◽  
Polymeric Materials ◽  
Gellan Gum ◽  
Traditional Use

Rheumatoid arthritis is a rheumatic disease for which a healing treatment does not presently exist. Silk fibroin has been extensively studied for use in drug delivery systems due to its uniqueness, versatility and strong clinical track record in medicine. However, in general, natural polymeric materials are not mechanically stable enough, and have high rates of biodegradation. Thus, synthetic materials such as gellan gum can be used to produce composite structures with biological signals to promote tissue-specific interactions while providing the desired mechanical properties. In this work, we aimed to produce hydrogels of tyramine-modified gellan gum with silk fibroin (Ty–GG/SF) via horseradish peroxidase (HRP), with encapsulated betamethasone, to improve the biocompatibility and mechanical properties, and further increase therapeutic efficacy to treat rheumatoid arthritis (RA). The Ty–GG/SF hydrogels presented a β-sheet secondary structure, with gelation time around 2–5 min, good resistance to enzymatic degradation, a suitable injectability profile, viscoelastic capacity with a significant solid component and a betamethasone-controlled release profile over time. In vitro studies showed that Ty–GG/SF hydrogels did not produce a deleterious effect on cellular metabolic activity, morphology or proliferation. Furthermore, Ty–GG/SF hydrogels with encapsulated betamethasone revealed greater therapeutic efficacy than the drug applied alone. Therefore, this strategy can provide an improvement in therapeutic efficacy when compared to the traditional use of drugs for the treatment of rheumatoid arthritis.

scholarly journals Effect of SWCNT-Tuball Paper on the Lightning Strike Protection of CFRPs and Their Selected Mechanical Properties

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3140
Author(s):  
Kamil Dydek ◽  
Anna Boczkowska ◽  
Rafał Kozera ◽  
Paweł Durałek ◽  
Łukasz Sarniak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Copper Foil ◽  
Impact Resistance ◽  
Mechanical Analysis ◽  
Lightning Strike ◽  
Single Wall Carbon Nanotubes ◽  
Carbon Fibre Reinforced Polymer ◽  
The Impact

The main aim of this work was the investigation of the possibility of replacing the heavy metallic meshes applied onto the composite structure in airplanes for lightning strike protection with a thin film of Tuball single-wall carbon nanotubes in the form of ultra-light, conductive paper. The Tuball paper studied contained 75 wt% or 90 wt% of carbon nanotubes and was applied on the top of carbon fibre reinforced polymer before fabrication of flat panels. First, the electrical conductivity, impact resistance and thermo-mechanical properties of modified laminates were measured and compared with the reference values. Then, flat panels with selected Tuball paper, expanded copper foil and reference panels were fabricated for lightning strike tests. The effectiveness of lightning strike protection was evaluated by using the ultrasonic phased-array technique. It was found that the introduction of Tuball paper on the laminates surface improved both the surface and the volume electrical conductivity by 8800% and 300%, respectively. The impact resistance was tested in two directions, perpendicular and parallel to the carbon fibres, and the values increased by 9.8% and 44%, respectively. The dynamic thermo-mechanical analysis showed higher stiffness and a slight increase in glass transition temperature of the modified laminates. Ultrasonic investigation after lightning strike tests showed that the effectiveness of Tuball paper is comparable to expanded copper foil.

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