scholarly journals Design of Support Pillar Arrays in Flat Evacuated Windows

1991 ◽  
Vol 44 (5) ◽  
pp. 545 ◽  
Author(s):  
RE Collins ◽  
AC Fischer-Cripps
Keyword(s):  
Stress Concentration ◽  
Tensile Stress ◽  
Atmospheric Pressure ◽  
Thermal Conductance ◽  
Design Procedure ◽  
Pillar Array ◽  
Pillar Arrays ◽  
Support Pillar ◽  
Glass Plates ◽  
Mechanical Tensile

Flat evacuated glazing consists of two plane sheets of glass separated by a narrow evacuated space. These structures must incorporate an array of support pillars in order to maintain the separation of the glass plates under the influence of atmospheric pressure forces. A design procedure is outlined for determining the dimensions of this pillar array. Two important constraints in the design process are the mechanical tensile stress on the outside of the glass plates near the pillar, and the thermal conductance through the array of support pillars. A third constraint arises because of stress concentration near the pillars on the inside of the window. Evacuated windows having usefully low values of thermal conductance through the pillar array and tolerably small levels of exterior tensile stress can only be produced if large stresses exist on the inside of the structure in the region of the glass plates near the support pillars. The implications of these stresses are discussed. It is concluded that it is possible to design a pillar array for which the localised tensile stresses and overall thermal conductance have usefully small values.

Determination of DC06+ZE Sheet Crack Cause

2016 ◽  
Vol 368 ◽  
pp. 121-125
Author(s):  
Pavel Kejzlar ◽  
Tomáš Pilvousek ◽  
Michal Tregler
Keyword(s):  
Stress Concentration ◽  
Tensile Stress ◽  
Deep Drawing ◽  
Crack Formation ◽  
Local Stress ◽  
Local Deformation ◽  
Local Stress Concentration ◽  
Bcc Lattice ◽  
Hard Particles

The present work deals with determination of the cause of crack occurring in a part of car body manufactured from deep-drawing sheet. UHR-SEM, EDS, EBSD and measurement of microhardness were used for evaluation of the structure, local deformation and crack formation mechanism. A material analysis discovered foreign particles in the material. These particles were identified as MgAl2O4 with BCC lattice. The occurrence of these hard particles led to local stress concentration, decrease in mechanical strength and sheet breach due to tensile stress during deformation.

Simulation of the Optical Properties for Silicon Nano-Pillar Array Using Finite Difference Time Domain Method

2009 ◽  
Vol 60-61 ◽  
pp. 367-370 ◽  
Author(s):  
Yuan Xun Liao ◽  
Fu Ting Yi
Keyword(s):  
Finite Difference ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Wave Length ◽  
Time Domain Method ◽  
Small Deviations ◽  
Pillar Array ◽  
Domain Method ◽  
Pillar Arrays ◽  
Difference Time

We use two-dimensional FDTD (Finite difference time domain) method to simulate light transmitting in Si nano-pillar arrays and get some results. The Si nano-pillar array, with diameters, heights, intervals respectively 50-80nm, less than 480nm, 26-44nm, is used as the testifying structure. The reflectivities of both experiment and simulation match well either for bulk silicon or for structure silicon even though small deviations are caused by the uneven size of the pillar’s diameters, heights, and intervals. What’s more, we find reflectivity (ref) increases along with diameter’s (d) increasing for a single pillar with diameters of 20-100nm under a constant light of 600nm, and reaches 10.48% at d=100nm. And with a constant d equal to 20nm, an infinite aspect ratio (r) and a light 600nm, ref is decreasing when the intervals (i) of pillars are increasing. Finally, under the condition of different i, the relations between ref and r are investigated. The undulation of these curves shows that the reflective waves play an important role in sub-wave length optics. Analysis also reveals that there exists a best i for achieving the lowest ref, too large or too small i will cause high ref, even if r is great; moreover, the lager i is, the higher pillar is needed to achieve the lowest ref.

Functional Toxicology and Pharmacology Test of Cell Induced Mechanical Tensile Stress in 2D and 3D Tissue Cultures

2018 ◽  
pp. 157-192
Author(s):  
Gerhard M. Artmann ◽  
Jürgen Hescheler ◽  
Haritha Meruvu ◽  
Sefa Kizildag ◽  
Aysegül Artmann
Keyword(s):  
Tensile Stress ◽  
Tissue Cultures ◽  
Mechanical Tensile ◽  
2D And 3D

A Tensile Stress Concentration Equation for Countersunk Holes

2007 ◽  
Vol 44 (1) ◽  
pp. 194-200 ◽  
Author(s):  
Kunigal N. Shivakumar ◽  
Anil Bhargava ◽  
James C. Newman
Keyword(s):  
Stress Concentration ◽  
Tensile Stress ◽  
Concentration Equation

scholarly journals Microfabrication of High-Aspect Ratio KNN Lead-Free Piezoceramic Pillar Arrays by Aqueous Gelcasting

Ceramics ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 287-296
Author(s):  
Cailing Wu ◽  
Benke Li ◽  
Xiaofeng Wang ◽  
Feng Ji ◽  
Dou Zhang ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Lead Free ◽  
Solid Loading ◽  
High Mechanical Strength ◽  
Pillar Array ◽  
Novel Approach ◽  
Pillar Arrays ◽  
Gelcasting Process

The present paper reported a novel approach for the fabrication of a high-aspect ratio (K, Na)NbO3 (KNN) piezoelectric micropillar array via epoxy gelcasting, which involves the in situ consolidation of aqueous KNN suspensions with added hydantoin epoxy resin on a polydimethylsiloxane (PDMS) soft micromold. KNN suspensions with solid loadings of up to 45.0 vol.% have rheological behavior, which was suitable for the gelcasting process. The uniform green KNN bodies derived from the optimized suspension of 42.0 vol.% solid loading and 15.0 wt.% resin had exceptionally high mechanical strength (9.14 MPa), which was responsible for the integrity of the piezoceramic micropattern structure. The square-shaped KNN piezoelectric pillar array with lateral dimensions of up to 5 μm and an aspect ratio of up to five was successfully fabricated.

Study on Constructional Reinforcement for the Foundation of Blast Furnace due to Temperature Effect

2011 ◽  
Vol 94-96 ◽  
pp. 1545-1548
Author(s):  
Ying Min Li ◽  
Lu Wang ◽  
Li Ping Liu
Keyword(s):  
Blast Furnace ◽  
Numerical Analysis ◽  
Stress Concentration ◽  
Tensile Stress ◽  
Temperature Effect ◽  
Circular Area ◽  
Concrete Hydration ◽  
Concrete Hardening ◽  
Small Spacing

Based on the test and numerical analysis, the paper studied the constructional reinforcement of blast furnace foundation under the influence of concrete hydration and top temperature. The results indicate that constructional reinforcement should be thinner and have a small spacing. Stress concentration always appears around the corner and constraints of blast furnace foundation, where should be strengthened with constructional reinforcements. In order to prevent cracks caused by internal tensile stress during concrete hardening, it is necessary to place temperature reinforcement inside the foundation. Temperature effect should be considered at the circular area on top of blast furnace foundation and should be strengthened with constructional reinforcements.

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