Modal Properties of Hybrid Carbon/Kevlar Composite Thin Plate and Hollow Wing Model

2013 ◽  
Vol 446-447 ◽  
pp. 597-601
Author(s):  
H. Haidzir ◽  
Dayang Laila Majid ◽  
A.S.M. Rafie ◽  
M.Y. Harmin
Keyword(s):  
Mechanical Properties ◽  
Thin Plate ◽  
Composite Plate ◽  
Natural Frequencies ◽  
Computational Procedure ◽  
Modal Testing ◽  
Wing Model ◽  
Natural Modes ◽  
Superior Mechanical Properties ◽  
Hybrid Carbon

In any flutter prediction analysis, modal testing is necessary because flutter, a resonant like vibration occurs at a flutter frequency and adopts a mode shape akin to its structural natural modes. Modal testing can be performed computationally with knowledge of the mechanical properties of the structure. In the present work, computational modal analysis is first performed on a cantilevered hybrid composite thin plate and validated experimentally. Then, the computational procedure is demonstrated on a composite hollow wing model of same material. The concept of hollow wing is explored due to the superior mechanical properties of carbon/kevlar composite plate. It is observed that the natural frequencies of the hollow wing model are higher than thin plate due to stiffer configuration. A breathing mode was also observed at mode 4 for the hollow wing.

Metallic Nanoneedles Arrays for TEM Sample Preparation “Lift-Out”

2012 ◽  
Author(s):  
Romaneh Jalilian ◽  
David Mudd ◽  
Neil Torrez ◽  
Jose Rivera ◽  
Mehdi M. Yazdanpanah ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Sample Preparation ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam System ◽  
Transmission Electron ◽  
Nanoneedle Array ◽  
Superior Mechanical Properties ◽  
And Performance

Abstract The sample preparation for transmission electron microscope can be done using a method known as "lift-out". This paper demonstrates a method of using a silver-gallium nanoneedle array for a quicker sharpening process of tungsten probes with better sample viewing, covering the fabrication steps and performance of needle-tipped probes for lift-out process. First, an array of high aspect ratio silver-gallium nanoneedles was fabricated and coated to improve their conductivity and strength. Then, the nanoneedles were welded to a regular tungsten probe in the focused ion beam system at the desired angle, and used as a sharp probe for lift-out. The paper demonstrates the superior mechanical properties of crystalline silver-gallium metallic nanoneedles. Finally, a weldless lift-out process is described whereby a nano-fork gripper was fabricated by attaching two nanoneedles to a tungsten probe.

Dually cross-linked single network poly(acrylic acid) hydrogels with superior mechanical properties and water absorbency

Soft Matter ◽  
2016 ◽  
Vol 12 (24) ◽  
pp. 5420-5428 ◽  
Author(s):  
Ming Zhong ◽  
Yi-Tao Liu ◽  
Xiao-Ying Liu ◽  
Fu-Kuan Shi ◽  
Li-Qin Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Acrylic Acid ◽  
Water Absorbency ◽  
Superior Mechanical Properties ◽  
Poly Acrylic Acid

Effect of Interfacial Properties on the Mechanical Behavior of Bone-Like Materials: A Numerical Study

2017 ◽  
Vol 09 (01) ◽  
pp. 1750014 ◽  
Author(s):  
Xingguo Li ◽  
Bingbing An ◽  
Dongsheng Zhang
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Numerical Study ◽  
Element Model ◽  
Interfacial Behavior ◽  
Yield Behavior ◽  
Bonding Property ◽  
The Matrix ◽  
Bonding Properties ◽  
Superior Mechanical Properties

Interfacial behavior in the microstructure and the plastic deformation in the protein matrix influence the overall mechanical properties of biological hard tissues. A cohesive finite element model has been developed to investigate the inelastic mechanical properties of bone-like biocomposites consisting of hard mineral crystals embedded in soft biopolymer matrix. In this study, the complex interaction between plastic dissipation in the matrix and bonding properties of the interface between minerals and matrix is revealed, and the effect of such interaction on the toughening of bone-like biocomposites is identified. For the case of strong and intermediate interfaces, the toughness of biocomposites is controlled by the post yield behavior of biopolymer; the matrix with low strain hardening can undergo significant plastic deformation, thereby promoting enhanced fracture toughness of biocomposites. For the case of weak interfaces, the toughness of biocomposites is governed by the bonding property of the interface, and the post-yield behavior of biopolymer shows negligible effect on the toughness. The findings of this study help to direct the path for designing bioinspired materials with superior mechanical properties.

Exploitation Load Impact on Electrochemical Properties of Shipbuilding 7xxx Series Aluminum Alloy Joints Prepared with TIG and FSW Methods

2015 ◽  
Vol 236 ◽  
pp. 53-61
Author(s):  
Wojciech Jurczak
Keyword(s):  
Mechanical Properties ◽  
Corrosion Potential ◽  
Tensile Load ◽  
Electrochemical Corrosion ◽  
High Strength ◽  
Shipbuilding Industry ◽  
Friction Stir ◽  
Superior Mechanical Properties ◽  
Series Aluminum Alloy ◽  
Joint Quality

The paper presents the results of investigations on mechanical properties and electrochemical potential distribution within arc welded (TIG) and friction stir welded (FSW) joints subjected to slow strain rate tests. The materials investigated were high-strength 7xxx series (7020 and its modification 7020M) aluminum alloys intended for shipbuilding. The objectives were joint quality assessment and comparison of the advantages of new FSW method with the traditional TIG methods commonly utilized in shipbuilding industry. Joint quality was evaluated based on mechanical investigations, hardness distribution tests and simultaneous electrochemical corrosion potential measurements at various locations within the welded joints.Initiation of corrosion processes on TIG and FSW joints was identified as a radical decrease in corrosion potential related to load followed by oxide layer cracking. Arc welded (TIG) joints of 7xxx series alloys undergo corrosion at lower values of tensile load applied as compared to the FSW joints. Superior mechanical properties and higher corrosion resistance of the FSW joints make this technology well-suited for joining high-strength 7xxx series alloys.

Hybrid silica micro and PDDA/nanoparticles-reinforced carbon fibre composites

2016 ◽  
Vol 51 (6) ◽  
pp. 783-795 ◽  
Author(s):  
Júlio C Santos ◽  
Luciano MG Vieira ◽  
Túlio H Panzera ◽  
André L Christoforo ◽  
Marco A Schiavon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Fibre ◽  
Silica Nanoparticles ◽  
Fibre Composite ◽  
Flexural Modulus ◽  
Specific Chemical ◽  
Diallyldimethylammonium Chloride ◽  
Fibre Composites ◽  
Carbon Fibre Composites ◽  
Hybrid Carbon

The work describes the manufacturing and testing of novel hybrid epoxy/carbon fibre composites with silica micro and poly-diallyldimethylammonium chloride-functionalised nanoparticles. A specific chemical dispersion procedure was applied using the poly-diallyldimethylammonium chloride to avoid clustering of the silica nanoparticles. The influence of the various manufacturing parameters, particles loading, and mechanical properties of the different phases has been investigated with a rigorous Design of Experiment technique based on a full factorial design (2131). Poly-diallyldimethylammonium chloride-functionalised silica nanoparticles were able to provide a homogenous dispersion, with a decrease of the apparent density and enhancement of the mechanical properties in the hybrid carbon fibre composites. Compared to undispersed carbon fibre composite laminates, the use of 2 wt% functionalised nanoparticles permitted to increase the flexural modulus by 47% and the flexural strength by 15%. The hybrid carbon fibre composites showed also an increase of the tensile modulus (9%) and tensile strength (5.6%).

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