Characterization of structural adhesives for load-bearing composite structural applications

1994 ◽  
Vol 27 (1-2) ◽  
pp. 57-64 ◽  
Author(s):  
K.J. Ahn ◽  
Y.S. Eom ◽  
Y.T. Shim ◽  
J.C. Seferis
Keyword(s):  
Load Bearing ◽  
Structural Adhesives ◽  
Structural Applications

Acoustic characterization of silica nanoparticle-impregnated Kevlar fabric

2021 ◽  
pp. 004051752110238
Author(s):  
Oluwafemi P Akinmolayan ◽  
James M Manimala
Keyword(s):  
Transmission Loss ◽  
Silica Nanoparticle ◽  
Air Gap ◽  
Thin Plates ◽  
Residual Porosity ◽  
Ballistic Performance ◽  
Number Of Layers ◽  
Structural Applications ◽  
Acoustic Characterization

Silica nanoparticle-impregnated Kevlar (SNK) fabric has better specific ballistic performance in comparison to its neat counterparts. For multifunctional structural applications using lightweight composites, combining this improved ballistic functionality with an acoustic functionality is desirable. In this study, acoustic characterization of neat and SNK samples is conducted using the normal-incidence impedance tube method. Both the absorption coefficient and transmission loss (TL) are measured in the 60–6000 Hz frequency range. The influence of parameters such as number of layers of neat or treated fabric, percentage by weight of nanoparticle addition, spacing between fabric layers, and residual porosity is examined. It is found that while absorption decreases with an increase in nanoparticle addition for frequencies above about 2500 Hz, increasing the number of layers shifts peak absorption to lower frequencies. By introducing an air-gap behind the fabric layer, dominant low-frequency (1000–3000 Hz) absorption peaks are obtained that correlate well with natural modes of mass-equivalent thin plates. Examining the influence of residual porosity by laminating the SNK samples reveals that it contributes to about 30–50% of the total absorption. Above about 1500 Hz, 3–5 dB of TL increase is obtained for SNK samples vis-à-vis the neat samples. TL is found to increase beyond that of the neat sample above a threshold frequency when an air-gap is introduced between two SNK layers. With an increase in the weight of nanoparticle addition, measured TL tends to be closer to mass law predictions. This study demonstrates that SNK fabric could provide improved acoustic performance in addition to its ballistic capabilities, making it suitable for multifunctional applications and could form the basis for the development of simplified models to predict the structural acoustic response of such nanoparticle–fabric composites.

Obtention of an Al-Based Composite Material by Direct Fusion of Used Beverage Cans

2012 ◽  
Vol 706-709 ◽  
pp. 271-276 ◽  
Author(s):  
Claudia Carrasco ◽  
C. Montalba ◽  
Carlos Camurri
Keyword(s):  
Composite Material ◽  
Aluminium Alloys ◽  
Metal Matrix ◽  
Mechanical Analysis ◽  
Heat Treated ◽  
Structural Applications ◽  
Metal Matrix Composite Material ◽  
Direct Fusion ◽  
Scanning Electron

In the present study, the fabrication of an Al-based metal matrix composite material obtained directly from the melting of the aluminium used beverage cans in a modified rheocasting process is presented. The analysed operational condition is the shear rate applied to the bath and its influence on the properties of the obtained samples. Additionally, samples were heat treated at two different times. The characterization of the phases obtained in Al-based MMC was made by means of metallography, scanning electron microscopy with energy dispersive spectroscopy and electron microprobe with wavelength dispersion spectroscopy. The results show that some constituents were formed during the fabrication process of the MMC, mainly Al6(Fe, Mn), which are partially transformed during the heat treatment. Additionally, samples were evaluated using dynamic mechanical analysis, and the results suggest that the obtained MMC could have very good mechanical properties, similar or superior to the aluminium alloys commonly used for structural applications such as 6XXX family.

Synthesis and characterization of mechanically strong carboxymethyl cellulose–gelatin–hydroxyapatite nanocomposite for load-bearing orthopedic application

2017 ◽  
Vol 53 (1) ◽  
pp. 230-246 ◽  
Author(s):  
Chandrani Sarkar ◽  
Pushpa Kumari ◽  
Kumar Anuvrat ◽  
Sumant Kumar Sahu ◽  
Jui Chakraborty ◽  
...  
Keyword(s):  
Carboxymethyl Cellulose ◽  
Synthesis And Characterization ◽  
Load Bearing

scholarly journals Fabrication and Characterization of Ta–GelMA–BG Scaffolds by Chemical Crosslinking Processing for Promotion Osteointegration

2021 ◽  
Vol 8 ◽  
Author(s):  
Fujian Zhao ◽  
Xiongfa Ji ◽  
Yang Yan ◽  
Zhen Yang ◽  
Xiaofeng Chen ◽  
...  
Keyword(s):  
Early Stage ◽  
Bone Defects ◽  
Chemical Crosslinking ◽  
Composite Scaffolds ◽  
Load Bearing ◽  
3D Printed ◽  
Fabrication And Characterization ◽  
Cell Adhesion And Proliferation

The repair of bone defects in load-bearing positions still faces great challenges. Tantalum (Ta) has attempted to repair bone defects based on the excellent mechanical properties. However, the osseointegration of Ta needs to be improved due to the lack of osteoinduction. Herein, tantalum–gelatin–methacryloyl–bioactive glass (Ta–GelMA–BG) scaffolds were successfully fabricated by loading BG in 3D-printed Ta scaffolds through a chemical crosslinking method. The results showed that the composite scaffolds have the ability to promote cell adhesion and proliferation. The incorporation of BG resulted in a significant increase in apatite-forming and osteogenesis differentiation abilities. In vivo results indicated that the Ta–GelMA–BG scaffolds significantly enhanced the osteointegration at the early stage after implantation. Overall, the Ta–GelMA–BG scaffolds are a promising platform for the load bearing bone regeneration field.

scholarly journals Fabrication and Mechanical Characterization of Stir Cast AA6063-Borosilicate-Fly Ash Hybrid Metal Matrix Composites

2018 ◽  
Vol 7 (3.6) ◽  
pp. 101 ◽  
Author(s):  
G Jims John Wessley ◽  
A Gaith Franklin ◽  
S J. Vijay
Keyword(s):  
Wear Resistance ◽  
Fly Ash ◽  
Aluminium Alloy ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Wear Test ◽  
Hardness Test ◽  
Structural Applications

This paper presents the development and characterization of aluminium alloy 6063 based metal matrix composite with varying combinations of fly ash and Borosilicate reinforcements.  In the present work, the aluminium alloy 6063 (AA) is taken at a constant 84 vol% while the reinforcements Fly Ash (FA) and Borosilicate (B) are varied in the proportions of 2%, 4% 8%, 125 and 14%. Six samples were fabricated by stir casting and the mechanical properties were analyzed using tensile test, hardness test and wear test while the microstructure is analyzed by obtaining SEM and EDX images of the specimen. It is seen that both the reinforcements used in this study, increased the tensile and wear resistance of the alloy. The desirable mechanical and micro structural properties were found to be in the specimen with 84% AA, 14% FA and 2% B. The tensile strength of the aluminum alloy at this desirable combination is found to increase by 11.97%, ductility by 36.75% and the wear resistance by 62%.  This metal matrix composite of AA6063 with fly ash and Borosilicate reinforcements can be used in automobile, aerospace and structural applications where wear resistance and tensile properties are mainly required.

Damping and Bandgap Characteristics of a Viscoelastic Tensegrity Damper

2021 ◽  
pp. 1-47
Author(s):  
Mohamed Raafat ◽  
Amr Baz
Keyword(s):  
Mathematical Model ◽  
Material Characterization ◽  
Structural Vibrations ◽  
New Class ◽  
Structural Applications ◽  
Theoretical Predictions ◽  
Specific Frequency ◽  
The Mathematical Model ◽  
Theory And Experiments

Abstract A theoretical and experimental investigation of a new class of a tensegrity-based structural damper is presented. The damper is not only capable of attenuating undesirable structural vibrations, as all conventional dampers, but also capable of completely blocking the transmission of vibration over specific frequency bands by virtue of its periodicity. Such dual functionality distinguishes the tensegrity damper over its counterparts of existing structural dampers. Particular emphasis is placed here in presenting the concept and developing the mathematical model of the dynamics of a unit cell the damper. The model is then coupled with a Floquet-Bloch analysis in order to identify the bandgap characteristics of the damper. The predictions of the mathematical model are validated experimentally using a prototype of the damper which is built using 3D printing. A comprehensive material characterization of the damper is performed followed by a detailed extraction of the static and dynamic behavior of the damper in order to validate the theoretical predictions. Close agreement is observed between theory and experiments. The developed theoretical and experimental techniques provide invaluable means for the design of this new class of dampers particularly for critical structural applications.

Structural Characterization of Foamed Composite Structural Insulated Panel with Coir for Load Bearing Wall Application

2018 ◽  
Vol 934 ◽  
pp. 222-226
Author(s):  
Jericson H. Advincula ◽  
Dustin Glenn C. Cuevas ◽  
Allan Dave A. Dela Cruz ◽  
John Paul D. Carreon
Keyword(s):  
Flexural Strength ◽  
Structural Characterization ◽  
Exterior Wall ◽  
Load Bearing Capacity ◽  
Maximum Increase ◽  
Load Bearing ◽  
Permanent Formwork ◽  
Foamed Concrete ◽  
Design Loads

Permanent formwork building system is a method that uses the formwork as a contributor to the load bearing capacity of the structure. This study characterized the proposed foamed composite structural insulated panel (CSIP) with coir for load bearing wall application in low rise construction. The percentage of coir in foamed concrete that could significantly increase the compressive and flexural strength of the panel considering the effect of coir to the workability of the foamed concrete were determined. The results showed that the samples with 0.5% coir had the maximum increase in its compressive and flexural capacity and further addition of coir decreases its capacities. The results also showed that it could carry the required design loads. Moreover, using Euler’s buckling equation for the effect of slenderness, the panel could be used as exterior wall for a height of 2m, 3m, and 4m and as interior wall for a height of 2m and 3m. It can be concluded that the proposed panel could be used as a load bearing wall in low rise construction.

Constitutive Behavior and Testing of Structural Adhesives

1987 ◽  
Vol 40 (10) ◽  
pp. 1393-1402 ◽  
Author(s):  
Erol Sancaktar
Keyword(s):  
Mechanical Model ◽  
Material Characterization ◽  
Constitutive Relations ◽  
Superposition Principle ◽  
Surface Preparation ◽  
Ring Test ◽  
Stress Strain ◽  
Testing Procedures ◽  
Structural Adhesives

Material characterization of structural adhesives in the bulk and bonded forms is discussed. Constitutive relations used for describing stress–strain data are reviewed. The difficulties associated with adhesive characterization in the bonded form are cited. Common testing procedures for adhesive characterization in the bulk and bonded forms are reviewed. In presenting the constitutive relations used in material characterization of structural adhesives, deformation theories introduced by Hencky are reviewed first. The modifications made in this theory to render it rate dependent and bilinear are discussed and applications to adhesive characterization are cited. Application of linear viscoelasticity, mechanical model characterization, and its use in describing the dependence of adhesive and cohesive strengths on rate, temperature, and bond thickness are presented. The time–temperature superposition principle and three-dimensional stress–strain relations in integral and differential operator forms are reviewed. Frequent assumptions for dilatation and distortion operations are presented. Procedures for describing nonlinear viscoelastic behavior are reviewed. It is pointed out that the extent of nonlinearity is dependent on both the stress level and the time scale. The use of nonlinear spring and dashpot elements, nonlinear differential operators, and perturbation of elastic and viscous coefficients are cited. Prandtl’s incremental theory of plasticity and its extension in the form of over-stress theory is presented. The incorporation of this over-stress idea into the viscoelastic mechanical model characterization is discussed. The modified Bingham model and the Chase–Goldsmith model developed in this fashion and their application to adhesive material characterization are presented. The use of empirical relations for the description of creep behavior is discussed. Prediction of shear behavior based on bulk tensile data is demonstrated. It is suggested that characterization of adhesive behavior in the bonded form should include the application of stress analysis, fracture mechanics, polymer chemistry and surface analysis techniques. In testing bonded samples the use of thick adherend symmetric single lap geometry or napkin ring test geometry is advised and it is suggested that the specimens should be prepared with the same surface preparation and cure techniques.

Characterization of in-plane load bearing of a honeycomb paperboard

2018 ◽  
Vol 32 (1) ◽  
pp. 23-37 ◽  
Author(s):  
Xinni Mou ◽  
Lixin Lu ◽  
Wen Zhang ◽  
Haiyan Yang
Keyword(s):  
Load Bearing
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