Shock and vibration tests of space light-weighted corner cubes manufactured with adhesion process

The aim of this study was to evaluate the influence of anatomical characteristics on the adhesion performance of Vatairea sp., Paulownia sp., Aspidosperma populifolium and Tectona grandis wood. Specimens for anatomical, physical and mechanical analyzes were produced from tangentially oriented boards. The treatments were joint glued from pieces of the same anatomical orientation (radial and tangential), evaluated for shear strength and glue line failure. The Vatairea sp wood had the highest specific gravity (0.74 g cm-3) and the Paulownia sp (0.34 g cm-3) wood was smaller. Aspidosperma populifolium species showed the highest shear strength in the glue line in the tangential and radial faces. The anatomical variables with higher influence on the wood adhesion process were pith ray cells and especially fibers that exhibit the greatest correlation with the shear strength of the glue line.

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FEATURES OF SIMULATING THE FORCE ACTIONS FROM A DAMAGED ENGINE AT GROUND VIBRATION TESTS OF AN AIRPLANE

TsAGI Science Journal ◽

10.1615/tsagiscij.2017019466 ◽

2016 ◽

Vol 47 (6) ◽

pp. 649-663

Author(s):

Regina Vladimirovna Leonteva ◽

Vsevolod Igorevich Smyslov

Keyword(s):

Ground Vibration ◽

Vibration Tests

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Packaging. Complete, filled transport packages and unit loads. Sinusoidal vibration tests using a variable frequency

10.3403/02658686 ◽

2002 ◽

Keyword(s):

Variable Frequency ◽

Sinusoidal Vibration ◽

Vibration Tests

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Packaging. Complete, filled transport packages and unit loads. Vibration tests at fixed low frequency

10.3403/02797418u ◽

2015 ◽

Keyword(s):

Low Frequency ◽

Vibration Tests

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Effects of Precast Cladding Systems on Dynamic Characteristics of Steel Frame Buildings by Ambient and Free Vibration Tests

Shock and Vibration ◽

10.1155/2017/5231727 ◽

2017 ◽

Vol 2017 ◽

pp. 1-20 ◽

Cited By ~ 1

Author(s):

Jun Ma ◽

Shinji Nakata ◽

Akihito Yoshida ◽

Yukio Tamura

Keyword(s):

Free Vibration ◽

Dynamic Characteristics ◽

Steel Frame ◽

Ambient Vibration ◽

Test Cases ◽

Vibration Method ◽

External Wall ◽

Wide Range ◽

Cladding Panels ◽

Vibration Tests

Full-scale tests on a one-story steel frame structure with a typical precast cladding system using ambient and free vibration methods are described in detail. The cladding system is primarily composed of ALC (Autoclaved Lightweight Concrete) external wall cladding panels, gypsum plasterboard interior linings, and window glazing systems. Ten test cases including the bare steel frame and the steel frame with addition of different parts of the precast cladding system are prepared for detailed investigations. The amplitude-dependent dynamic characteristics of the test cases including natural frequencies and damping ratios determined from the tests are presented. The effects of the ALC external wall cladding panels, the gypsum plasterboard interior linings, and the window glazing systems on the stiffness and structural damping of the steel frame are discussed in detail. The effect of the precast cladding systems on the amplitude dependency of the dynamic characteristics and the tendencies of the dynamic parameters with respect to the structural response amplitude are investigated over a wide range. Furthermore, results estimated from the ambient vibration method are compared with those from the free vibration tests to evaluate the feasibility of the ambient vibration method.

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Lithium-Doped Biological-Derived Hydroxyapatite Coatings Sustain In Vitro Differentiation of Human Primary Mesenchymal Stem Cells to Osteoblasts

Coatings ◽

10.3390/coatings9120781 ◽

2019 ◽

Vol 9 (12) ◽

pp. 781 ◽

Cited By ~ 4

Author(s):

Paula E. Florian ◽

Liviu Duta ◽

Valentina Grumezescu ◽

Gianina Popescu-Pelin ◽

Andrei C. Popescu ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Doping Agent ◽

Hydroxyapatite Coatings ◽

3D Network ◽

Immunofluorescence Labelling ◽

Good Biocompatibility ◽

Adhesion Process

This study is focused on the adhesion and differentiation of the human primary mesenchymal stem cells (hMSC) to osteoblasts lineage on biological-derived hydroxyapatite (BHA) and lithium-doped BHA (BHA:LiP) coatings synthesized by Pulsed Laser Deposition. An optimum adhesion of the cells on the surface of BHA:LiP coatings compared to control (uncoated Ti) was demonstrated using immunofluorescence labelling of actin and vinculin, two proteins involved in the initiation of the cell adhesion process. BHA:LiP coatings were also found to favor the differentiation of the hMSC towards an osteoblastic phenotype in the presence of osteoinductive medium, as revealed by the evaluation of osteoblast-specific markers, osteocalcin and alkaline phosphatase. Numerous nodules of mineralization secreted from osteoblast cells grown on the surface of BHA:LiP coatings and a 3D network-like organization of cells interconnected into the extracellular matrix were evidenced. These findings highlight the good biocompatibility of the BHA coatings and demonstrate that the use of lithium as a doping agent results in an enhanced osteointegration potential of the synthesized biomaterials, which might therefore represent viable candidates for future in vivo applications.

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Measurement of Young’s Modulus and Shear Modulus of Some Structures Welded Using Flux Cored Wire by Vibration Tests

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.216.151 ◽

2014 ◽

Vol 216 ◽

pp. 151-156 ◽

Cited By ~ 1

Author(s):

Liviu Bereteu ◽

Mircea Vodǎ ◽

Gheorghe Drăgănescu

Keyword(s):

Shear Modulus ◽

Arc Welding ◽

Natural Frequencies ◽

Free Vibrations ◽

Vibration Modes ◽

Cored Wire ◽

Flux Cored Arc Welding ◽

Longitudinal Elastic Modulus ◽

Vibration Tests ◽

Non Destructive

The aim of this work was to determine by vibration tests the longitudinal elastic modulus and shear modulus of welded joints by flux cored arc welding. These two material properties are characteristic elastic constants of tensile stress respectively torsion stress and can be determined by several non-destructive methods. One of the latest non-destructive experimental techniques in this field is based on the analysis of the vibratory signal response from the welded sample. An algorithm based on Pronys series method is used for processing the acquired signal due to sample response of free vibrations. By the means of Finite Element Method (FEM), the natural frequencies and modes shapes of the same specimen of carbon steel were determined. These results help to interpret experimental measurements and the vibration modes identification, and Youngs modulus and shear modulus determination.

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