scholarly journals Pseudo Stable Phenomenon of Crack Extension in Three Point Bending Test for Soda-Lime Glass.

1996 ◽  
Vol 45 (3) ◽  
pp. 310-315
Author(s):  
Hidetoshi KOBAYASHI ◽  
Masashi DAIMARUYA ◽  
Taketoshi NOJIMA
2003 ◽  
Vol 17 (08n09) ◽  
pp. 1329-1334 ◽  
Author(s):  
Sang Yeob Oh ◽  
Hyung Seop Shin ◽  
Chang Min Suh

In applications of brittle materials such as soda-lime glass and ceramics, they are usually subjected to a multi-axial stress state. Brittle materials with cracks or damage caused by foreign impacts are apt to fracture abruptly from cracks because of their low fracture toughness. Depending upon the crack pattern developed, the strength using a multi-axial stress state might be different from the one using a uniaxial stress. As a result, when a small size crack was introduced by Vicker's indentation, the residual strength using a biaxial stress state obtained by the ball-on-ring test was greater than that using a uniaxial stress by the 4-point bending test. In the case of the specimens cracked by a spherical impact, there was overall decrease in the bending strength with increasing an impact velocity.


Author(s):  
Branimir Bajac ◽  
Jovana Stanojev ◽  
Slobodan Birgermajer ◽  
Milena Radojevic ◽  
Jovan Matovic

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 129
Author(s):  
Marcos Soldera ◽  
Sabri Alamri ◽  
Paul Alexander Sürmann ◽  
Tim Kunze ◽  
Andrés Fabián Lasagni

All-purpose glasses are common in many established and emerging industries, such as microelectronics, photovoltaics, optical components, and biomedical devices due to their outstanding combination of mechanical, optical, thermal, and chemical properties. Surface functionalization through nano/micropatterning can further enhance glasses’ surface properties, expanding their applicability into new fields. Although laser structuring methods have been successfully employed on many absorbing materials, the processability of transparent materials with visible laser radiation has not been intensively studied, especially for producing structures smaller than 10 µm. Here, interference-based optical setups are used to directly pattern soda lime substrates through non-lineal absorption with ps-pulsed laser radiation in the visible spectrum. Line- and dot-like patterns are fabricated with spatial periods between 2.3 and 9.0 µm and aspect ratios up to 0.29. Furthermore, laser-induced periodic surface structures (LIPSS) with a feature size of approximately 300 nm are visible within these microstructures. The textured surfaces show significantly modified properties. Namely, the treated surfaces have an increased hydrophilic behavior, even reaching a super-hydrophilic state for some cases. In addition, the micropatterns act as relief diffraction gratings, which split incident light into diffraction modes. The process parameters were optimized to produce high-quality textures with super-hydrophilic properties and diffraction efficiencies above 30%.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2450
Author(s):  
Andreas Borowski ◽  
Christian Vogel ◽  
Thomas Behnisch ◽  
Vinzenz Geske ◽  
Maik Gude ◽  
...  

Continuous carbon fibre-reinforced thermoplastic composites have convincing anisotropic properties, which can be used to strengthen structural components in a local, variable and efficient way. In this study, an additive manufacturing (AM) process is introduced to fabricate in situ consolidated continuous fibre-reinforced polycarbonate. Specimens with three different nozzle temperatures were in situ consolidated and tested in a three-point bending test. Computed tomography (CT) is used for a detailed analysis of the local material structure and resulting material porosity, thus the results can be put into context with process parameters. In addition, a highly curved test structure was fabricated that demonstrates the limits of the process and dependent fibre strand folding behaviours. These experimental investigations present the potential and the challenges of additive manufacturing-based in situ consolidated continuous fibre-reinforced polycarbonate.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 488
Author(s):  
Oumaima Nasry ◽  
Abderrahim Samaouali ◽  
Sara Belarouf ◽  
Abdelkrim Moufakkir ◽  
Hanane Sghiouri El Idrissi ◽  
...  

This study aims to provide a thermophysical characterization of a new economical and green mortar. This material is characterized by partially replacing the cement with recycled soda lime glass. The cement was partially substituted (10, 20, 30, 40, 50 and 60% in weight) by glass powder with a water/cement ratio of 0.4. The glass powder and four of the seven samples were analyzed using a scanning electron microscope (SEM). The thermophysical properties, such as thermal conductivity and volumetric specific heat, were experimentally measured in both dry and wet (water saturated) states. These properties were determined as a function of the glass powder percentage by using a CT-Meter at different temperatures (20 °C, 30 °C, 40 °C and 50 °C) in a temperature-controlled box. The results show that the thermophysical parameters decreased linearly when 60% glass powder was added to cement mortar: 37% for thermal conductivity, 18% for volumetric specific heat and 22% for thermal diffusivity. The density of the mortar also decreased by about 11% in dry state and 5% in wet state. The use of waste glass powder as a cement replacement affects the thermophysical properties of cement mortar due to its porosity as compared with the control mortar. The results indicate that thermal conductivity and volumetric specific heat increases with temperature increase and/or the substitution rate decrease. Therefore, the addition of waste glass powder can significantly affect the thermophysical properties of ordinary cement mortar.


2020 ◽  
Author(s):  
Iskender Akkurt ◽  
Kadir Gunoglu ◽  
Recep Kurtuluş ◽  
Taner Kavas

Heritage ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 524-540
Author(s):  
Philippe Colomban ◽  
Gulsu Simsek Franci ◽  
Farahnaz Koleini

In the late 19th century, ancient tombs were discovered near the village of Vohemar at the northeastern point of Madagascar, and subsequent excavations during the French period (1896–1945) revealed the presence of a major necropolis active from ~13th to 18th centuries. Some artefacts (Chinese ceramic shards and glass trade beads) recovered from these excavations was sent to France and now in part belong to the collection of the Musée d’Histoire Naturelle, Nimes. Carnelian and glass trade beads were analyzed with a mobile Raman spectrometer, which identified different materials (soda-lime glass, quartz/moganite, carnelian/citrine, chalcedony) and coloring agents (Naples yellow, cassiterite, amber chromophore, transition metal ions, etc.). The results are compared with those obtained on beads excavated at different sites of Southern Africa and at Mayotte Island, and it appears that (most of) the beads come from southern Asia and Europe. The results confirmed the role that northern Madagascar played within the maritime networks of the Western Indian Ocean during the 15th–16th century.


2015 ◽  
Vol 1100 ◽  
pp. 152-155
Author(s):  
Libor Topolář ◽  
Hana Šimonová ◽  
Petr Misák

This paper reports the analysis of acoustic emission signals captured during three-point bending fracture tests of concrete specimens with different mixture composition. Acoustic emission is an experimental tool well suited for monitoring fracture processes in material. The typical acoustic emission patterns were identified in the acoustic emission records for three different concrete mixtures to further describe the under-the-stress behaviour and failure development. An understanding of microstructure–performance relationships is the key to true understanding of material behaviour. The acoustic emission results are accompanied by fracture parameters determined via evaluation of load versus deflection diagrams recorded during three-point bending fracture tests.


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