THE METHODS OF DETERMINATION OF Al2O3 SINGLE-CRYSTAL FIBERS CROSS-SECTION AREA FOR TENSILE STRENGTH CALCULATION

AbstractThis study has deeply investigated the basic equations analysis of dispersion and loss in photonic crystal fibers (PCF) within the operating wavelengths of 850, 1,300, and 1,550 nm. The confinement loss, effective refractive index, and effective cross-section area of PCF are also studied. The variations of total dispersion and losses against hole diameter and distance between holes variations in PCF are clarified. Confinement loss, effective refractive index, and effective cross-section area variations for PCF are sketches with the variations of the operating wavelength.

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SHRINKAGE INFLUENCE ON STRESS-STRAIN STATE OF COMPOSITE MASONRY MEMBERS/SUSITRAUKIMO DEFORMACIJŲ ĮTAKA KOMPLEKSINIŲ MŪRO ELEMENTŲ ĮTEMPIŲ IR DEFORMACIJŲ BŪVIUI

Journal of Civil Engineering and Management ◽

10.3846/13921525.2001.10531721 ◽

2001 ◽

Vol 7 (3) ◽

pp. 177-183 ◽

Cited By ~ 2

Author(s):

Gediminas Marčiukaitis

Keyword(s):

Reinforced Concrete ◽

Cross Section ◽

Modulus Of Elasticity ◽

Masonry Structures ◽

Cross Section Area ◽

Section Area ◽

Deformation Properties ◽

Different Types ◽

Tension And Compression

Composite masonry structures consists of various units (bricks or ceramic, concrete and other blocks) masonry and concrete or reinforced concrete layers. Analysis has shown that in most cases deformation properties of masonry, concrete and reinforced concrete are different. There is a big difference in modulus of elasticity and shrinkage deformations. Methods for determination of shrinkage and modulus of elasticity for different types of masonry and reinforced concrete have been presented. Analysis of distribution of stresses and deformations in layers has shown that for a given difference of shrinkage in layers the stresses of tension and compression in the layers depend on the cross-section area of these layers and the ratio of the modulus of elasticity. Formulas are given for calculation of these stresses.

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Use Of Pulsed IR Thermography For Determination Of Size And Depth Of Subsurface Defect Taking Into Account The Shape Of Its Cross-Section Area

Archives of Metallurgy and Materials ◽

10.1515/amm-2015-0181 ◽

2015 ◽

Vol 60 (2) ◽

pp. 615-620 ◽

Cited By ~ 5

Author(s):

O. Wysocka-Fotek ◽

M. Maj ◽

W. Oliferuk

Keyword(s):

Cross Section ◽

Rectangular Cross Section ◽

Time Derivative ◽

Equivalent Diameter ◽

Ir Thermography ◽

Flat Bottom ◽

Surface Distribution ◽

Cross Section Area ◽

Section Area

Abstract The paper is devoted to reconstruction of size and depth (distance from the tested surface) of artificial defects with square and rectangular cross-section areas using the pulsed IR thermography. Defects in form of flat-bottom holes were made in austenitic steel plate. The defect size was estimated on the basis of surface distribution of the time derivative of the temperature. In order to asses the depth of defects with considered geometries on the basis of calibration relations (i.e. dependence of time of contrast maximum vs. defect depth for given defect diameter) obtained for circular defects, the ‘equivalent diameter’ describing not only the defect cross-section area but also its shape was assigned. It has been shown that presented approach gives satisfactory results.

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Tests of Concrete Strength across the Thickness of Industrial Floor Using the Ultrasonic Method with Exponential Spot Heads

Materials ◽

10.3390/ma13092118 ◽

2020 ◽

Vol 13 (9) ◽

pp. 2118 ◽

Cited By ~ 6

Author(s):

Bohdan Stawiski ◽

Tomasz Kania

Keyword(s):

Compressive Strength ◽

Cross Section ◽

Cross Sections ◽

Ultrasonic Method ◽

Concrete Strength ◽

Testing Machine ◽

Cross Section Area ◽

Section Area ◽

Strength Result

The accepted methods for testing concrete are not favorable for determining its heterogeneity. The interpretation of the compressive strength result as a product of destructive force and cross-section area is burdened with significant understatements. It is assumed erroneously that this is the lowest value of strength at the height of the tested sample. The top layer of concrete floors often crumble, and the strength tested using sclerometric methods does not confirm the concrete class determined using control samples. That is why it is important to test the distribution of compressive strength in a cross-section of concrete industrial floors with special attention to surface top layers. In this study, we present strength tests of borehole material taken from industrial floors using the ultrasonic method with exponential spot heads with a contact surface area of 0.8 mm2 and a frequency of 40 kHz. The presented research project anticipated the determination of strength for samples in various cross-sections at the height of elements and destructive strength in the strength testing machine. It was confirmed that for standard and big borehole samples, it is not possible to test the strength of concrete in the top layer of the floor by destructive methods. This can be done using the ultrasonic method. After the analysis, certain types of distributions of strength across concrete floor thickness were chosen from the completed research program. The gradient and anti-gradient of strength were proposed as the new parameters for the evaluation of floor concrete quality.

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