Determination of Shear Stress in Pull out Tests in Laminated Bamboo Guadua angustifolia

2015 ◽  
Vol 668 ◽  
pp. 17-22 ◽  
Author(s):  
Caori Patricia Takeuchi ◽  
Martin Estrada ◽  
Dorian Luis Linero
Keyword(s):  
Shear Strength ◽  
Shear Stresses ◽  
Average Value ◽  
Pull Out ◽  
Laminated Bamboo ◽  
Tension Tests ◽  
Cross Section Area ◽  
Section Area ◽  
The Common

Specimens of laminated bamboo Guadua angustifolia do not usually fail due to fiber breakage when submitted to shear stresses. The common failure mechanism in that case is slippage in the fiber-matrix interface, accompanied by degradation of the lignin matrix (parenchyma). In this study the shear strength of laminated bamboo Guadua angustifolia specimens was determined by tension tests reducing the cross section area. The perimeter of the slipped area was determined using digital image processing. Shear stresses were calculated taking into account the load and slipped area in specimens of two different groups, depending on the orientation of the laminated boards. It was found that the average value of the shear strength on pull out tests were 2.9 MPa, which is a mechanical property of the material that is useful, for example, in the analysis of the behavior of the joints, and analysis of the fracture process.

Dimensioning of Aerated Grit Chambers and Use as a Highly Loaded Activated Sludge Process

1989 ◽  
Vol 21 (4-5) ◽  
pp. 13-22
Author(s):  
Jorg Londong
Keyword(s):  
Activated Sludge ◽  
Pilot Scale ◽  
Air Injection ◽  
Activated Sludge Process ◽  
Cross Section Area ◽  
Section Area ◽  
Degree Of Separation ◽  
Highly Loaded ◽  
Adsorption Stage

The aerated grit chamber has long been used to separate sand from sewage. Nevertheless, there are no definite and uniform recommendations for dimensioning, and there is little information in the literature about the degree of separation attainable. Thus, principles for dimensioning and the possible degree of separation are derived from measurements of large pilot scale plants, two-dimensional models, and existing aerated grit chambers. The following values for dimensioning were found in this work: a detention period of about 20 minutes; a width to depth ratio (w/d) of about 0.8; a minimal and maximal cross section area between 1 and about 7 m2; a flow velocity of 20 cm/s at the bottom of the aerated grit chamber. Simple formulae for the determination of the required amount of air can be given in relation to the w/d ratio, the depth of air injection and the kind of aeration used (fine or coarse bubble). The simultaneous use of an aerated grit chamber as an adsorption stage (highly loaded activated sludge process) is possible without additional air being required to maintain the velocity at the bottom of the grit chamber. For purely aerobic operation, however, the amount of air has to be increased.

Deformation of ice under high internal shear stresses

1969 ◽  
Vol 6 (4) ◽  
pp. 963-968 ◽  
Author(s):  
John J. Jonas ◽  
Fritz Müller
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Polarized Light ◽  
Shear Stresses ◽  
Strain Rates ◽  
Transparent Plastic ◽  
Cross Section Area ◽  
Section Area ◽  
Polycrystalline Ice ◽  
Glacier Surges

By means of transparent plastic dies, cylindrical samples of single crystal and polycrystalline ice were extruded into rods of one quarter the original cross-section area. The deformation was carried out at −5 °C and a mean strain rate of about 10−2 s−1. With the aid of polarized light, the formation of cracks and the occurrence of dynamic recrystallization were studied. The experiments of Steinemann, and more recent results in metals suggest that, during such plastic flow, two types of dynamic recrystallization are involved. At low strain rates, the recrystallization is periodic, leading to rapid increases in strain rate at constant applied stress; at higher strain rates, the recrystallization is continuous and the strain rate is constant. The possibility that dynamic recrystallization of the periodic type is associated with glacier surges is discussed.

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

2001 ◽  
Vol 7 (3) ◽  
pp. 177-183 ◽  
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.

In-Plane Shear Strength Determination of Composite Materials in Laminated and Sandwich Panels

1997 ◽  
Vol 50 (11S) ◽  
pp. S237-S240 ◽  
Author(s):  
J. R. Vinson
Keyword(s):  
Shear Strength ◽  
Composite Materials ◽  
Test Procedure ◽  
Sandwich Panels ◽  
Laminated Composite ◽  
Adhesive Bond ◽  
Shear Stresses ◽  
Plane Shear ◽  
Laminated Composite Materials

A simple test procedure is available to determine the in-plane shear strength of laminated composite materials, as well as other orthotropic and isotropic advanced material systems. The test apparatus is simple, inexpensive, and the flat rectangular plate test specimen is not restricted in size or aspect ratio. In addition to its use for laminated composite materials, the test can also be used for foam core sandwich panels. In sandwich panels, the tests can be used to determine the in-plane shear strength of the faces, the core and/or the adhesive bond between face and core. The shear stresses developed vary linearly in the thickness direction and are constant over the entire planform area.

scholarly journals LCDiXRay: a user-friendly program for powder diffraction indexing of columnar liquid crystals

2014 ◽  
Vol 47 (2) ◽  
pp. 668-679 ◽  
Author(s):  
Nicolas Godbert ◽  
Alessandra Crispini ◽  
Mauro Ghedini ◽  
Manuela Carini ◽  
Francesco Chiaravalloti ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Structural Information ◽  
Structural Parameters ◽  
X Ray Diffraction ◽  
Cell Parameters ◽  
Cross Section Area ◽  
Section Area ◽  
Columnar Mesophases ◽  
User Friendly

The formulation of a standard computerized procedure for the indexing of powder X-ray diffraction (PXRD) patterns of columnar liquid crystals, with the determination of all structural information extracted from a properly indexed PXRD spectrum and the attribution of the columnar mesophase symmetry, is presented. In particular, the proposed program notably accelerates the identification of columnar mesophases together with thein situdetermination of their structural parameters such as mesophase type, space group, cell parameters, cross-section area, intermolecular stacking distance between consecutive discoids and, in the case of ordered mesophases, the estimation of the number of molecules constituting each discoid.

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

2015 ◽  
Vol 60 (2) ◽  
pp. 615-620 ◽  
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.

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

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2118 ◽  
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.

Shear Strength Parameters Determination of Compacted Loess with Compression-Tension Tests

2011 ◽  
Vol 287-290 ◽  
pp. 1271-1274
Author(s):  
Xiao Jun Li
Keyword(s):  
Shear Strength ◽  
Dry Weight ◽  
Tension Test ◽  
Shear Strength Parameters ◽  
Strength Index ◽  
Strength Parameters ◽  
Weight Density ◽  
Tension Tests ◽  
Compacted Loess

Compression-tension test and direct shear test are used to evaluate the shear behavior of remolded loess under different water content and different dry weight density. Through massive analysis of test data, it is found that the valves of c and φ determined by compression-tension test can be used to characterize the shear strength index of soil.

Sign in / Sign up

Export Citation Format

Share Document